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Accumulation of potentially toxic elements in road deposited sediments in residential and light industrial neighborhoods of Singapore
... As in other maps of various metals such as Zn (Figure 2), Ni ( Figure 8) and Cr ( Figure 10), where their highest concentration was found at the same point, to the southwest, in this case, the highest PLI value (57) is found in the same place, as this point is a touristcommercial area where many people transit throughout the day. ...
... As in other maps of various metals such as Zn (Figure 2), Ni ( Figure 8) and Cr (Figure 10), where their highest concentration was found at the same point, to the southwest, in this case, the highest PLI value (57) is found in the same place, as this point is a touristcommercial area where many people transit throughout the day. ...
... The average Pb concentration in Cartagena was 227.2 mg kg −1 (Table 1), slightly higher than in Murcia [31], Mexico City [6] or Singapore [57]. Decades ago, vehicle emissions were the main source of Pb emissions, but with the elimination of Pb in fuels in 1970, emissions decreased drastically [46]. ...
In the present work, a study has been carried out on the contamination of heavy metals in urban dust deposited on the roads of the city of Cartagena (Spain) in order to know the content of metals such as Ni, Zn, Pb, Cd, Cr and Cu. Likewise, the possible relationship between the concentration of heavy metals and the color of the sample, level of magnetism and traffic density was studied. Contamination was evaluated using several indices such as contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), pollutant load index (PLI) and ecological risk index (RI). A total of 88 samples were taken in the urban area of Cartagena, and the metals were determined by acid digestion and measured by inductively coupled plasma mass spectrometry. The concentration of heavy metals in urban dust from Cartagena was Zn (672 mg kg−1) > Cu (248.9 mg kg−1) > Pb (227 mg kg−1) > Cr (82.7 mg kg−1) > Ni (47.7 mg kg−1) > Cd (4.1 mg kg−1). Contamination levels were high in Pb, Zn, Cd and Cu, according to environmental indices. A correlation was found between magnetism and metal concentration, which was repeated for all metals except Cd. Dark-colored samples contained higher metal concentrations than light-colored samples. Meanwhile, streets with medium and low traffic intensity were found to have higher concentrations of heavy metals. This study’s objective was to identify pollution hotspots caused by heavy metals in dust in the urban ecosystem of Cartagena city.
... There were industrial and mining enterprises near Quanji River. Typical components of the industry include Ni, As, Pb, Cd, and Cu (Pourkhabbaz and Pourkhabbaz, 2012;Yuen et al., 2012;McComb et al., 2015;Chen et al., 2016), and untreated industrial wastewater and sewage discharge may be sources of these PTEs (Shamuyarira and Gumbo, 2014;Rzetala, 2016;Gopinathan et al., 2022). These human activities may be the reason for the high concentration of PTEs in the sediments of the Quanji River. ...
... Pb and Zn have been identified as tracers for transportation Zhao et al., 2019a). Previous studies have found that Pb is mainly related to exhaust emissions from automobiles, tire erosion, and wear (Pourkhabbaz and Pourkhabbaz, 2012;Yuen et al., 2012;Reshmi, 2022). Zn is an essential component of tires, and frequent wear results in zinc particles entering the soil (Trujillo et al., 2016;Yadav et al., 2019). ...
... Consequently, Pb and Zn have been identified as tracers for transportation Zhao et al., 2019a). Cd, Cu, and Ni are commonly used in tires, brakes, and lubricants (Pourkhabbaz and Pourkhabbaz, 2012;Yuen et al., 2012;Long et al., 2021). Additionally, Cd and Cu are believed to be tracer elements of agriculture (Cai et al., 2019;Fei et al., 2019) due to their accumulation primarily from the use of pesticides and fertilizers (Yang et al., 2018;Qu et al., 2018). ...
... The anthropogenic emission of metals is more complex, mainly from industrial activities and vehicle-related emissions. The former includes raw metal materials used, the building industry, smelting, mechanical engineering, coal burning, pesticide industry, electroplating, and steel industry, and the latter involves fuel emissions, tires, brake pads, vehicle equipment, and asphalt wear (Fukuzaki et al., 1986;Fergusson and Kim, 1991;Miner, 1993;Lindgren, 1996;De Miguel et al., 1997;Zayed et al., 1999;Mokrzycki et al., 2003;Yokel and Delistraty, 2003;Zhang et al., 2004;Faiz et al., 2009;Wei et al., 2009;Lu et al., 2010;Shi et al., 2010;Duong and Lee, 2011;Ren et al., 2011;Chen et al., 2012Chen et al., , 2013Chen et al., , 2014Yuen et al., 2012;Duan and Tan, 2013;Valotto et al., 2015;Ali et al., 2017;Pan et al., 2017;Tang et al., 2017). Moreover, waste combustion and construction and demolition operations are among the sources of metal pollution in street dust (Gunawardana et al., 2012;Saeedi et al., 2012). ...
... In comparison to urban areas in Nanjing, China (Li et al., 2013), Ulsan, Korea (Duong and Lee, 2011), Kuala Lumpur, Malaysia (Mun'im Mohd Mun'im Mohd Han et al., 2014), and Luanda, Angola (Ferreira-Baptista and De Miguel, 2005), the most metal content in street dust in Miaoli townships shows a tendency of much greater concentration. For the Steel Enterprise area in Xihu, except Pb and Zn in street dust collected from the industrial area in Huludao, China, Pb in Kavala, Greece, Co and Cr in Delhi, India, as well as Co, Ni, and Pb in Singapore, has the highest metal concentration in street dust than in the industrial area in other countries (Christoforidis and Stamatis, 2009;Zheng et al., 2010;Yuen et al., 2012;Pathak et al., 2013;Tang et al., 2017;Skrbic et al., 2018). ...
... The rest of the metals are less than 10%, which means that Pb has an independent pollution source, speculating that it may be caused by the asphalt road and the friction between the road surface paint and the vehicle, resulting in the discharge of Pb from asphalt and paint (Fergusson and Kim, 1991). Factor 3 has the highest proportion in the contribution percentage of Ni and Cr, which are 73.3% and 46.1%, respectively, and the remaining Sb, Cu, Zn, Fe, and Co also have a contribution percentage of 10%-20%, so it is speculated that the pollution sources may be the wear of vehicle brake pads and emissions from metal and machinery-related industries (Shi et al., 2010;Duong and Lee, 2011;Yuen et al., 2012;Chen et al., 2014). Factor 4 has the highest contribution percentage of Zn at 82.1%, and it is suggested that the source pollution may be mainly the wear and tear of vehicle tires (Fukuzaki et al., 1986;Yuen et al., 2012;Duan and Tan, 2013). ...
Due to the numerous industrial parks and high traffic density in Miaoli, Taiwan, large amounts of metals may be released into the atmosphere, accumulating in street dust. Therefore, this study aimed to collect street dust in Miaoli to quantify the metals and assess the accumulation degree, sources, and potential risks. The enrichment factor (EF), geological accumulation index (Igeo), ecological risk, and non-carcinogenic and lifetime carcinogenic risk were estimated to assess the accumulation degree and the potential environmental and health risks. Pearson correlation analysis, principal component analysis, and positive matrix factor model were used to clarify the relationship between levels of metals and identify possible sources. The levels of metals in street dust in order were Fe > Zn > Mn > Cu > Cr > Ni > Pb > Sr > Co > Sb. According to Igeo, the level of Ni indicated moderately polluted. The levels of Zn, Cu, and Pb showed moderate to strong pollution, strong pollution, and very strong pollution, respectively. Results of average ecological risk analysis pointed out that Pb and Cu represent a very high risk, while other metals posed low-to moderate-level ecological risks. Excluding the Steel Enterprise area, based on the EF value and source identification, it might be concluded that Co, Sr, Fe, Mn, and Sb were mainly from natural sources, while Cu, Pb, and Zn come from anthropogenic pollution sources. Based on the results of the risk assessments, most metals pose no serious adverse health risk to humans. But, in comparison to Miaoli townships, the health risks of residents living in the Steel Enterprise area were higher. However, given that children and adolescents exposure to Co, Cr, Pb, and Ni together constitute a relatively higher carcinogenic risk (CR > 10-6), more attention needs to be paid to the populations most susceptible.
... Traffic and industrial emissions are main contributors of intense toxic metal pollution on the environment (Duong and Lee, 2011;Guney et al., 2010;Yuen et al., 2012;Mmaduakor et al., 2022) and are the source of Pb, Zn, Cu and Cd (Nduka and Orisakwe, 2010), whereas Ni interrelated both to naturally occurring sources and emanates from industrial processes. Cr, Pb, Sn and Zn are linked with atmospheric deposition (Shi et al., 2008). ...
... When EF is close to 1, it indicates a natural source while EF > 10 suggests an anthropogenic source. According to Yuen et al. (2012) the Enrichment factor (EF) is defined by: ...
... A look at roadside soil (RS), PC1 had high loading for As, Ni, Cu, Fe, Mn and Pb which accounts for 67.82% of total variance. Traffic and industrial emissions are the most important contributors to increased concentration of toxic metal pollution in the environment (Duong and Lee, 2011;Guney et al., 2010;Yuen et al., 2012;Mmaduakor et al., 2022) and are the most common toxic metal pollutants include Pb, Zn, Cu and Cd (Nduka and Orisakwe, 2010), whereas Ni are interrelated both to naturally occurring sources and can emanates from industrial toxins. Cr is linked with atmospheric deposition (Shi et al., 2008). ...
Heavy metals posed threat to humans and environment. Spatial distribution/source identifications of heavy metals in soil, dust and water along major road of three economic zone of Enugu: Enugu/PH road (Industrial area), Agbani Road (Residential) and Ogui New Layout Road (Com-mercial) were evaluated. Soil and dust samples were collected at 15 cm depth and 1 m from roads, underground water at 65 m from roadside between December 2020-April 2021. Heavy metals were quantified by AAS. Heavy metals (mg/kg) in roadside soil varied from 0.00 to 0.05 (Cr), 1.50-4.00 (As), 0.08-6.93 for Ogui. The level of heavy metals (mg/ kg) in roadside dust ranged from 0.00 to 0.18 (Cr), 0.00-2.33 (As), 0.85-2.05 for Ogui. As in water Enugu/PH (0.081 mg/L), Agbani (0.079 mg/L) and Ogui (0.150 mg/L). Principal component analysis indicated that Cr, As, Ni, Cu, Hg, Pb Fe and Mn distributions were affected by traffic, industrial release and natural sources, ecological analysis showed low to moderate pollution. Risk assessment (children/adults) via each pathway were HI <1. Estimated cancer risk of 75% heavy metals via CR ing / inh / der (soil, dust water) below 1× 10 − 6-1 × 10 − 4 , total cancer risk shows high probability of carcinogenic risk via ingestion as children > adult susceptibility on prolonged exposure to vehicular activity, hence alarming contamination status of heavy metals in Enugu and associated health risk.
... Figure 2 presents the values of the Igeo index. An enrichment factor (EF) can be used to assess metal contamination of ro and the likely contribution of anthropogenic sources [36,53,54]. Slightly differen were obtained by analyzing the values of the EF index than the Igeo values. ...
... Figure 3 shows the EF values. An enrichment factor (EF) can be used to assess metal contamination of road dust and the likely contribution of anthropogenic sources [36,53,54]. Slightly different results were obtained by analyzing the values of the EF index than the Igeo values. ...
... Figure 2 presents the values of the Igeo index. An enrichment factor (EF) can be used to assess metal contamination of ro and the likely contribution of anthropogenic sources [36,53,54]. Slightly different were obtained by analyzing the values of the EF index than the Igeo values. ...
This paper presents an analysis of the content and spatial distribution of heavy metals (HM) in street dust in Suwałki, a city located in northeastern Poland. The HM content of street dust was also evaluated using the geochemical index (Igeo), enrichment factor (EF), and contamination factor (CF), and local HM sources were identified using chemometric methods. The arithmetic averages of HM contents in dust arranged in the following order: Fe > Zn > Mn > Cu > Cr > Ni > Pb, were 11,692.80, 215.97, 194.78, 142.84, 63.59, 17.50, 17.04 mg∙kg−1, respectively. Higher values than the local background occurred for Cr, Cu, Ni, Zn and Pb. The values of Igeo, CF, and EF indicate that the highest pollution in dust is due to Zn and Cu. The spatial distribution of metals was evaluated using maps of HM content in road dust samples from Suwałki. The spatial distribution of HM showed areas with high contents of Cr, Cu, Ni, Zn and Pb located mainly in the central and eastern parts of the city. In these areas, high traffic volume, the presence of shopping centers, administrative buildings and bus stops dominate. Statistical models of multivariate analysis (FA) and cluster analysis (CA) identified two sources of HM. The first source of pollution was associated with local industrial activity and motor vehicle travel, and the second with natural sources.
... To that end, the nation aims to double the number of community gardens and allotments from 1500 to 3000 plots by 2030 (Begum 2020). The growing prevalence of gardens within public housing estates in Singapore that are visited frequently by onsite residents potentially represent an uncertain health risk because the gardens are inherently located in a dense matrix of industrial and residential land-uses with high road densities (Ng et al. 2006;Joshi and Balasubramanian 2010;Yuen et al. 2012). Further, other green landscapes such as public parks and accessible woodlands are also frequently visited locations of potential exposure to PTEs (Han et al. 2017). ...
... Several studies have examined selected PTEs in a variety of Singaporean soils/sediments, including forests (Nguyen et al. 2018(Nguyen et al. , 2020Leitgeb et al. 2019;Wang et al. 2022), landfills (Patra et al. 2017), mangroves (Cuong et al. 2005), water bodies (Sin et al. 1991;Chen et al. 1996Chen et al. , 2016Nguyen et al. 2018), marine sediments (Rahman et al. 1979;Goh and Chou 1997;Wood et al. 1997;Cuong et al. 2008), military lands (Nguyen et al. 2019), road dust (Joshi and Balasubramanian 2010;Joshi et al. 2009;Yuen et al. 2012); fly ash (Tan et al. 1997;Wu and Ting 2006); and various types of urban lands (Zhou et al. 1997;Ng et al. 2006). The studies of Chen (1999), Zhou et al. (1997), and Wang et al. (2022) Fig . 2 The map shows major land-cover/land-use types in Singapore, with sample locations shown as diamonds (community gardens), circles (public parks) and triangles (woodlands). ...
... The main sources of high PTE concentrations in Singapore soils are likely vehicular phenomena and industrial activities (Zhou et al. 1997;Wood et al. 1997). For example, Yuen et al. (2012) reported roads in or near industrial areas had higher levels of PTEs in surficial dust compared with residential areas (Table 2). Joshi et al. (2009) reported very high concentrations of Cu (9069 ± 3742 mg/kg) and Zn (1696 ± 446 mg/kg) for road sediment in industrial areas. ...
Background
Urban agriculture is potentially an important piece of the food security puzzle for a rapidly growing urban world population. Community gardening is also promoted as a safe and viable form of exercise for aging populations in crowded settings where opportunities to participate in other action activities may be limited. Knowledge of potential site-specific health risks to environmental contaminants is important in dialogues promoting urban farming.
Methods
We assess the pseudo-total concentrations of selected potentially toxic elements (PTEs) in the soils of community gardens, public parks, and woodlands in the tropical urban island nation of Singapore. We compare concentrations of cadmium, copper, lead, and zinc with amalgamated risk guidelines to form a baseline understanding of the level of contamination in these spaces. We also perform providence tracking with lead isotopes to identify potential sources of contaminants.
Results
All pseudo-total concentrations of Cd, Cu, Pb, and Zn in the soil were below threshold concentrations considered to represent substantial risk. Further, PTE concentrations in gardens were largely equivalent to those found in community parks and woodlands, but the geographical distribution varied. Provenance tracking with Pb isotopes indicated Pb in gardens was both anthropogenic and natural, but spatially variable. The lack of strong spatial clustering of areas with the highest PTE concentrations was inconsistent with a common point source of contamination. However, the correlation between Cu and Zn suggest a common source for these elements, such as road/trafficking or atmospheric deposition.
Conclusion
We find limited risk of urban gardeners to exposure to Cd, Cu, Pb, and Zn—elements that are commonly abundant in urban settings with dense transportation networks and substantial industrial activities. The low levels of PTEs are encouraging for the promotion of urban farming for food production and leisure in this dense urban setting. However, as concentrations were low, we did not assess bioavailability and bioaccessibility of the PTEs. These assessments would need to be determined in cases of with higher levels of contamination to provide a more thorough consideration of actual human risk.
... For this purpose, it is necessary to identify, assess and quantify the concentrations of heavy metals in road dust and in the adjacent soil arable layer. Traffic and industrial emissions, are considered important factors in metal pollution in road dust [1][2][3]. With the phasing out of leaded gasoline in developed countries and the implementation of other control measures, traffic-related metal emissions had significantly decreased [4,5]. ...
... The Enrichment factor, is a parameter that, allows to see whether the concentration of heavy metals obtained in soils are anthropogenic or natural in origin [26]; if EF close to 1 indicates a natural source while EF > 10 suggests an anthropogenic source. According to Yuen et al. [3] the Enrichment factor (EF) is defined by: ...
... where: (C i / ) Sample and (C i / ) Background are the ratios of metal concentration (i), standardizer (Fe) in sample, metal concentration (i) and standardizer (Fe) in the background material, respectively. In this research, the (Fe) has been used as a standardizer because it has low variability in occurrence and is a main component of the Earth's crust [27,28]; and soils 80m from the roadway were used as reference materials [3,13] ...
This study is one of the first works which examined the assessment of heavy metal contamination of pavement-side soils in Algeria. It deals with the section of National Highway 3 (RN3), which crosses the wilaya of Batna. In the environment of sampling sites there is no industry or dangerous activity on the environment, the heavy metals addressed in this study are (Pb, Cu, Cr, Fe, Ni, Zn), their origin being road traffic. The objectives of this study were to: (1) Determine the concentrations of heavy metals in road dust; (2) Identify the sources of different heavy metals in soils and road dust; (3) Exploring the extent of heavy metal pollution in neighbouring soils. To this end, 33 samples were collected, including 03 road dust and 30 soil samples over different distances from 1m to 80m. The samples were analyzed by FRX. Results indicated that concentrations in road dust were higher than in soil. The distribution of heavy metal concentrations in dust is Fe>Pb>Zn>Cu>Cr>Ni, and the distribution in the ground is Fe>Pb>Cu>Zn>Cr>Ni in the direction of Biskra and in the opposite direction and decreases away from the road, while the distribution in the central solid ground is Fe> Cu>Cr>Pb>Zn>Ni. Climatic conditions such as wind, rainfall, temperature, humidity and the nature of the terrain were also significantly related to their enrichment in these roadside soils. The enrichment factor (EF) and the geo-accumulation index (Igeo) were calculated, as well as all elements with a (EF) that ranges from moderate to high to extremely contaminated, reflecting the high anthropogenic load of these metals in the study area and the results of the Igéo accumulation indices confirm the results obtained for the enrichment factor (EF). Doi: 10.28991/cej-2021-03091736 Full Text: PDF
... The enrichment factor (EF) is a widely used index for evaluating the degree of PTEs enrichment in atmospheric dust (Yuen et al., 2012) and investigating the possible effects of anthropogenic activities on their concentration (Soltani et al., 2015). EF was calculated using the following equation (Eq. ...
... where M c is the concentration of the target PTE in Zahedan atmospheric dust samples, M r is the concentration of aluminium (Al) as a reference element (Yuen et al., 2012), s indicates the studied sample, and b represents the background used in this study, which was the PTE concentration in the Upper Continental Crust (UCC; Taylor & McLennan, 2003). ...
Zahedan City is situated in the Sistan basin, a highly active dust source region that poses significant risks to human and ecological health due to potentially toxic elements (PTEs) present in atmospheric dust. In this study, we investigated the concentration, sources, and human health risk assessment of PTEs in 88 monthly atmospheric dust samples collected between December 2020 and October 2021 using inductively coupled plasma mass spectrometry. The results showed that the concentrations of PTEs in atmospheric dust followed the descending order of Mn > Zn > Ba > Sr > Cr > V > Ni > Cu > Pb > Co > As > Mo > Cd. The calculated enrichment factors revealed significant enrichment for As > Zn, moderate enrichment Pb > Ni, deficiency to minimal enrichment for Cr > Mn > Fe > Sr > Cd > V > Cu > Ba > Co, and no enrichment for Mo. Arsenic was found to be the major contributor to the potential ecological risk index, accounting for 55% of the total risk. The widespread utilization of arsenic-based pesticides in the surrounding agricultural lands may be a significant contributor to the severe arsenic pollution in the region. The winter season exhibited the highest monthly mean concentrations of Zn and Pb possibly due to temperature inversions trapping local anthropogenic pollutants near the Earth's surface. Cluster analysis revealed a strong correlation between Ni–Cr–Fe–V–Mn–Al, which shows mainly the geogenic source for these elements. The predominant exposure route for non-carcinogenic risk to humans was ingestion. The hazard index (HI) values for the heavy metals studied decreased in the following order: Cr > As > Pb > Ni > Zn > Cu > Cd, for both children and adults. The HI values indicated that there was no possible non-carcinogenic risk associated with exposure to these heavy metals in Zahedan's atmospheric dust. The result of the inhalation cancer risk assessment suggested that while the potential risks of cancer for As, Cd, Cr, and Ni were below the safe level, the levels of Chromium were close enough to the threshold to warrant further investigation and monitoring.
... Human activities are important factors that affect natural processes and the migration and accumulation of HMs: 1) Pointsource pollution of HMs from human activities: Golmud is the major industrial city in the Qaidam Basin. The typical components of industry include Ni, As, Pb, Cd, and Cu (Cheng and Hu, 2010;Pourkhabbaz and Pourkhabbaz, 2012;Yuen et al., 2012;McComb et al., 2015;Chen et al., 2016). Previous studies revealed that untreated industrial wastewater and sewage discharge might be the source of Ni, Cd, Pb, and Cu (Shamuyarira and Gumbo, 2014;Rzetala, 2016;Gopinathan et al., 2022c). ...
... These transportation lines parallel the Golmud River (Xiang, 2020). Pb, Zn, Cu, and As are the main elements in traffic exhaust and dust (Lough et al., 2005;Cheng and Hu, 2010;Pourkhabbaz and Pourkhabbaz, 2012;Yuen et al., 2012;McComb et al., 2015;Zhao et al., 2019). Therefore, transportation emissions directly caused linear pollution in the Golmud River. ...
The water quality of the Golmud River is essential for environmental preservation and economic growth of Golmud city and Qarhan Salt Lake in China. Thirty-four samples of surface water and sediment from seventeen places in the Golmud River and thirty-two dustfall samples in the Qaidam Basin were collected. The concentrations of heavy metals (HMs) were measured; water quality, risk assessment, and multiple source analysis were applied. Concentrations of HMs in water were Zn > Cu > Ni > As > Pb > Cd > Hg, and in sediment were Ni > Zn > Pb > As > Cu > Cd > Hg. In water, the Nemerow pollution index (NP) values indicated that most of the sampling points seemly were seriously polluted; other water quality assessment results suggested no pollution. In sediment, the concentrations of 27% HMs exceeded the background values of soil in Qinghai; 48% exceeded the Earth crust background values, which were As, Hg, and Cd. The single factor index method (Pi), geological accumulation index (Igeo), and contamination factor (CF) revealed that As pollution is serious, followed by Hg and Cd; the pollution load index (PLI) and modified pollution index (mCd) values indicated that 64% and 57% of samples were polluted. NP values are shown serious pollution. The ecological risk results demonstrated a low risk in water and a medium risk in sediment. The average total hazard quotient values in sediment and water for adults and children revealed low non-carcinogenic risks. Carcinogenic risk indicated Ni in water and sediment, and As in sediment may be involved in cancer risk. Multivariate statistics showed that the HMs mainly came from nature, and human activities will also impact them. The upper continental crust values indicated that As and Hg have high background values. The saline dust storm was one of the essential sources of HMs, especially Hg. Various provenances constituted the material cycling of HMs in the surface environment.
... The solution was transferred to a volumetric flask and diluted to 25 ml. All the glassware and plastic vessels were rinsed by dilute (1:1) nitric acid for 24 h and then washed with water (Yuen et al. 2012;Mohammed et al. 2020;Pradhan and Ambade 2020). Metals (Cr, Ni, Cu, Pb, Al, and Cd) in SPM samples were determined by analytical method using inductively coupled plasma (ICP, Perkin Elmer). ...
... In this study, the estimated annual Al and Pb metals have higher concentration in SPM than the other investigated metals; this may be attributed to industry processes. This is in accordance with Yuen et al. (2012). In contrast, Cd metal has the lowest concentration. ...
This study aims to estimate the association between some heavy metals in suspended particulate matter (SPM) and kidney damage among workers at different departments in a secondary aluminum production plant. It also investigates the association between Xeroderma Pigmentosum complementation group D (XPD) gene polymorphisms and worker’s susceptibility to kidney dysfunction. It was conducted on 30 workers from the administrative departments and 147 workers from different departments in the production line. Estimation of some heavy metals (Al, Co, Ni, Cu, Pb, and Cd) in suspended particulate matter (SPM) is done. Also, urinary levels of those metals were measured for all workers. Kidney injury molecule 1 (KIM-1), clusterin levels, and XPD protein level were estimated. Genotyping of XPD gene polymorphisms was performed. The measured annual average concentrations of the estimated heavy metals were lower than the permissible limits. Gravity area had the maximum concentration of metals with a higher Al average daily dose and hazardous index > 1. Kidney injury biomarkers (clusterin and KIM-1) were increased significantly (p < 0.05) while XPD protein showed the lowest levels among workers at the gravity and cold rolling areas. XPD Asn/Asp genotype was more dominant among those workers (85.7%). Conclusion: aluminum workers are at risk of kidney disorders due to heavy metal exposure. The individual’s susceptibility to the diseases is related to the DNA repair efficiency mechanisms. The defect in XPD protein represents a good indicator of susceptibility to the disease. KIM-1 and clusterin estimation is a predictor biomarker for early-staged kidney diseases.
... (Cr), 2.3-7.2 (Ni), 30-46 (Cu), 19-25 (Pb), and 34-38 (Zn) using upper crustal average values and Al as a reference element (Yuen et al., 2012). Overall, this study reports relatively higher enrichment factors for several metals. ...
... Direct comparison of PLI values from different regions of the world is difficult due to differences in geochemical background, land use, industrial history, population, number of vehicles driven per unit population, etc., between cities as well as differences in the metals used for PLI calculation. Earlier studies of road dusts reported average PLI values of 2.0-2.6 (averages of different areas in Shanghai, China), 1.5-6.5 (Loudi, China), 14.6 (residential area, Singapore) 20.6 (industrial area, Singapore), and 1.51 (Wuhan, China) Yuen et al., 2012;Zhang et al., 2012;Wang et al., 2019). Previous studies also reported PLI values in urban soils of 2.38 (Kaifeng City, China), 1.1 (range = 0.2-13.4; ...
Inhalation and/or ingestion of toxic heavy metals enriched in road dust have toxic effects on humans. From inhalation and ingestion of dust, release of readily bioavailable elements sorbed on to dust, could lead to health issues such as lung or skin cancer, kidney dysfunction, hypertension, dermal lesions, peripheral neuropathy, and vascular disease. On 49 road dust and soil samples collected in the Metro Detroit area, we analyzed a suite of trace metals in <63 μm and size-separated fractions to quantify the extent of metal enrichment and contamination status. We evaluated Enrichment Factor (EF), Pollution Index (PI), Geoaccumulation Index (GI), and Pollution Load Index (PLI). The average Chromium (Cr) concentration of 198 ppm is the highest reported for any global city in literature while in ∼80% samples, Barium (Ba), Cr, Lead (Pb), and Zinc (Zn) concentrations exceeded the USEPA limit. The EF for Barium (Ba) was found to be ≥9 in all samples, and for the rest of other elements was >1.5. The PI values for Cr, Ba, Zinc (Zn), Lead (Pb), and Selenium (Se) indicate elevated levels and for Ba, Cr, and Zn up to a moderate level. PLI values in >50% of road dusts were ≥3, indicating many sites are ‘heavily polluted’. The PLI value in Detroit road dust is higher than those reported for some other global cities including Shanghai. Observed strong correlations between Cr-Zn and Cadmium (Cd)-Silver (Ag) likely indicate a common metal source. Cluster analysis of data for Cd, Arsenic (As), Pb, and Zn appears to be distinct between different proximally related clusters, while Nickel (Ni) and Ba are potentially more distinct between property type clusters. In general, metal concentrations of industrial samples are more commonly distinct with over half of metals (≥6 of 11) differing from residential and/or soil samples. Three generalized “groups” were identified from the combination of hierarchical cluster and PCA analyses followed by varimax rotation: Group 1 characterized by Cr, Cd, Ni, Ag, Zn, and Copper (Cu); Group 2 characterized by Pb, As, Mercury (Hg), and minor Ba; and Group 3 characterized by Se. This is the first study to report all four metrics of metal pollution along with rigorous statistical analysis.
... In addition, bacteria, viral and parasitic diseases like typhoid, cholera, encephalitis, poliomyelitis, hepatitis, skin infection and gastrointestinal are spreading through polluted water. Among the pollutants, heavy metals are considered as one of the most serious environmental pollutants because of their high toxicity, abundance, and ease of accumulation by various organisms (Yuen et al. 2012;Swarnalatha et al. 2013). Accumulation may be magnified via the food chain, thereby threatening the marine ecosystem and human health (Satapathy and Panda 2017;Mazrouh and Mourad 2019). ...
The impact of human activities on some physicochemical parameters and heavy metals was studied in Lagos Lagoon, an eastern arm of the Gulf of Guinea. For ease of description, the 21 study stations were categorized into 6 regions. The mean surface and subsurface concentrations for water physicochemistry are temperature (27.34 ± 0.47 °C and 27.04 ± 0.67 °C), pH (7.86 ± 0.27 and 7.90 ± 0.29), dissolved oxygen (DO) (7.93 ± 1.11 mg/l and 6.95 ± 0.54 mg/l), Salinity (12.80 ± 12.74 ppt and 14.20 ± 13.80 ppt), turbidity (59.53 ± 43.94 NTU and 71.63 ± 49.96 NTU), nitrate (0.88 ± 0.35 mg/l and 0.82 ± 0.19 mg/l), phosphate (2.47 ± 1.55 mg/l and 1.96 ± 1.53 mg/l), silicate (2.13 ± 1.55 mg/l and 2.15 ± 1.95 mg/l). While the mean surface concentrations (µg/l) for the metals in decreasing order are Fe (162.22 ± 63.12), Pb (81.52 ± 48.56), Cu (74.19 ± 52.09), Zn (17.95 ± 16.27), Cd (15.33 ± 10.48), Ni (13.24 ± 8.60), the subsurface levels (µg/l) are Fe (179.88 ± 64.00), Cu (108.71 ± 66.64), Pb (54.43 ± 36.61), Ni (26.33 ± 18.28), Zn (25.48 ± 13.41), Cd (20.81 ± 16.81). Except for Pb and Cd, all the metals concentrations at both surface and subsurface are within the FEPA permissible limits. Contamination factor (CF) of the study area ranged from low contamination (0.1) to considerable contamination (3.08). Nemerow’s pollution index (NPI) the study area is within the good water quality (NPI < 1). Based on the outcome of this study, periodic assessment of Lagos lagoon is hereby suggested; this is with the view of ensuring adequate conservation of the lagoon system, particularly in maintaining the ecosystem services it provides within the region. There should be periodic review of the extant regulations controlling the dumping of chemical contaminants into the lagoon systems, especially in the aspects of their enforcement by the regulatory agencies, and compliance by the general public. Enlightenment programs for the public on the dangers associated with marine pollution are equally considered necessary.
... The average Pb concentration in Cartagena was 227 mg/kg (Table 1), slightly higher than in Murcia [31], Mexico City [6] or Singapore [56]. Decades ago, vehicle emissions were the main source of Pb emissions, but with the elimination of Pb in fuels in 1970, emissions decreased drastically [45]. ...
In the present work, a study has been carried out on the contamination of heavy metals in urban dust deposited on the roads of the city of Cartagena (Spain), in order to know the content of metals such as Ni, Zn, Pb, Cd, Cr and Cu. Likewise, the possible relationship of the concentration of heavy metals with the color of the sample, level of magnetism and traffic density was studied. Contamination was evaluated using several indices such as contamination factor (CF), enrichment factor (EF), geoacumulation index (Igeo), pollutant load index (PLI) and ecological risk index (RI). A total of 88 samples were taken in the urban area of Cartagena, and the metals were determined by acid digestion and measured by inductively coupled plasma mass spectrometry. The concentration of heavy metals in urban dust from Cartagena was Zn (672 mg/kg) > Cu (248.9 mg/kg) > Pb (227 mg/kg) > Cr (82.7 mg/kg) > Ni (47.7 mg/kg) > Cd (4.1 mg/kg). Contamination levels were high in Pb, Zn, Cd and Cu, according to environmental indices. A correlation was found between magnetism and metal concentration, which was repeated for all metals except Cd. Dark-colored samples contained higher metal concentrations than light-colored samples. Meanwhile, streets with medium and low traffic intensity were found to have higher concentrations of heavy metals. This study's objective was to identify pollution hotspots caused by heavy metals in dust in the urban ecosystem of Cartagena city.
... The amount of Cu and Ni was found in the roadside dust, proving that traffic mainly was responsible for this pollution. The combustion of fossil fuels and the processing of engine-wear particles results in the emission of significant quantities of nickel and copper into the atmosphere, as Yuen et al. (2012) reported. Zinc can be obtained through the mechanical abrasion of vehicle components. ...
Metal-containing dust is a potential severe environmental and human health threat. Metals present in dust may originate from car exhausts, tear and wear of tires, and vehicular emissions, which are less manageable. Metal-containing dust from roads can contaminate the soils, and crops alongside motorway. This study aimed to investigate the Pb Cd, Cu, Ni, and Zn concentrations in dust, soil, and vegetation collected from the M4 motorway Faisalabad. The results indicated that average metal concentrations in dust from all sites varies (Pb) 44.01 mg kg⁻¹, (Cd) 1.22 mg kg⁻¹, (Cu) 49.5 mg kg⁻¹, (Ni) 28.3 mg kg⁻¹, and (Zn) 113.7 mg kg⁻¹. The pollution assessment indices CF and PLI of Industrial city and Painsra had comparatively maximum levels of environmental pollution. Moreover, the geo-accumulation index (Igeo) of metals was high at Chak 115 and Painsra, while Igeo at ten sites was in the following descending order: Cd > Pb > Cu > Ni > Zn. Furthermore, it was identified that the maximum ecological risk index (Eⁱr) was in declining order, i.e., Cd > Pb > Cu > Ni > Zn, at all sites. The potential ecological risk was categorized as high risk in all respective sites. The particulate matter fractions PM2.5 and PM10 represented the maximum risk at the Industrial city site, which was unhealthy, although the Painsra site had poor air quality. The total suspended particulate was classified as hazardous at FDA city and Painsra. In contrast, food crops (maize, sugar cane, and sesame) and soil along the M4 motorway have similar Pb, Cd, Cu, Ni, and Zn contamination patterns like dust. However, two crops, maize and sugarcane, along the M4 motorway were found to be more polluted. The level of metals contamination through dust disposition was consistently higher adjacent to roads, possibly indicating depraved impacts on food crops.
... The Enrichment Factor (EF) is an informative indicator that provides insights into the condition and prevalence of environmental pollutions (Bourliva et al., 2017;Soltani et al., 2015;Yuen et al., 2012), specifically PTEs, within aquatic environments . The given equation represents the EF Eq. (2; Buat-Menard and Chesselet, 1979). ...
To assess the contamination sources, patterns, and environmental risk related to potentially toxic elements (PTEs) in the sediment of the region, ninety-seven surface sediment samples were systematically collected from the marine boundary of the Iranian coastal territory in the northwestern Persian Gulf. The concentrations of major and trace elements in the sediments can be ranked as follows: Ca > Al > Fe > Sr > Mn > Ba > Cr > Ni > V > Zn > Cu > Pb > As > Mo > Cd.
The study found that Ca, As, Sr, and Cd showed significant enrichment, while Ni and Cr showed moderate enrichment. The ecological risk index analysis indicated a low risk level, with Cd contributing to 61% and As contributing to 26% of the estimated risk. Anthropogenic sources were found to be responsible for significant enrichment of As and Cd in the northwestern Persian Gulf, particularly near coastal areas and in the Musa estuary. High concentrations of Arsenic result from urban/agricultural wastewater, industrial activities, and gas/oil fields. Natural weathering, riverbank erosion, and aeolian inputs also contribute to Arsenic levels. Cadmium pollution comes from wastewater, shipping, oil tankers, agriculture runoff, and industrial factories. Nickel and Chromium were moderately enriched, mainly due to their natural occurrence in high concentrations in the soil of southern Iran. The study also revealed a significant correlation among the elements Al, Ni, Cr, Fe, Mn, V, Zn, and Cu, suggesting that these elements predominantly originate from lithogenous sources. The study highlights the importance of identifying and controlling sources of As, Cd, Ni, and Cr pollution in the northwestern Persian Gulf to protect the marine ecosystem and public health. The implementation and enforcement of stricter environmental regulations can reduce PTEs contamination in the region and safeguard the aquatic ecosystem and public health.
... The enrichment factor (EF) was used to investigate the degree of metal enrichment from natural and anthropogenic sources depending on a reference element (widely used elements are Fe, Al, and Mn) to control the variations caused by heterogeneous samples (Bourliva et al., 2017;Wu et al., 2015;Yuen et al., 2012). It was computed using Equation (4) according to Buat-Menard and Chesselet (1979), where C x is the measured concentration of the metal x in the sample, C ref is the measured concentration of the chosen reference element in the sample, B x is the geochemical background value of the target element in the upper continental crust (Wedepohl, 1995), and B ref is the corresponding background concentration of the reference element. ...
Wadi El-Qamar is an unplanned area where industrial facilities are located adjacent to homes, which necessitated assessing the quality of the urban environment in this area by studying heavy metal contents as a source and sink of anthropogenic contaminants.
... The Enrichment Factor (EF) is a helpful indicator that reflects the status of environmental contaminants, particularly heavy elements, in marine environments [47,48]. The following equation expresses the EF Equation (1) [40,41]. ...
This study presents a comprehensive analysis of sediment texture along with geochemical variation, potential sources, and ecological risk assessment of major elements and trace metals in the bottom sediments of Iranian territorial waters situated in the northeast Persian Gulf. To achieve this, diverse laboratory methods, GIS techniques, statistical analyses, and index analysis approaches were employed. Over 50% of the sediment particles are mud, while one-third are sand-sized particles, primarily composed of skeletal fragments. The sediment's elements concentrations were ranked in descending order as Ca > Al > Fe > Sr > Mn > Ba > Cr > Ni > V > Zn > Cu > Pb > As > Co > Mo > Cd. Cluster analysis revealed strong correlations among Al-Ni-Cr-V, Cd-Cu-Zn-Pb, Ba-Fe, silt-clay, and Ca-Sr. Calcium and strontium showed extremely severe enrichment due to high content of carbonate matter. Arsenic and Mo were significantly enriched, while Ba, V, Co, Zn, and Cu demonstrated moderate enrichment. Nevertheless, all the sampling stations were classified as having zero to very low levels of contamination, indicating a low potential ecological risk. Arsenic emerged as the primary contributor to the ecological risk index. Notably, no strong correlation was found between As, Mo, and other elements, indicating that As and Mo likely originate from distinct sources.
... The deposited sediments come from natural processes such as dust storms, soil erosion, wildfires (Men et al., 2018;Jeong et al., 2021), and human-induced processes such as construction, mining operations, and fuel-burning (Niyogi, 2011). Fossil fuel burning occurs mainly in power generation plants and vehicles (Yuen, 2012). The sources are sometimes referred to as extrinsic and intrinsic sources ( Table 1). ...
... Fly ash can contain Cr and Cd and coal burning was also one of the main sources of Cr (Rout et al., 2015;Verma et al., 2015). Traffic-related materials can contain Pb and Zn, as they are used in products such as tires, brake lining, and brake pads (Grigoratos & Martini, 2015;Yuen et al., 2012). Furthermore, vehicular emission is also an important source of Pb (Cerda et al., 2011). ...
To investigate the temporal behaviors of heavy metals in sewage sludge in typical cities of industrial, industrial-agricultural, agricultural, or energy focused. Samples were collected every 10 days for a period of 1 year in four types of cities of Lanzhou, Tianshui, Qingyang, and Zhangye. The average annual values for all four cities were Cd (1.59–3.16 mg/kg), Pb (41.9–55.1 mg/kg), Cr (63.8–92.0 mg/kg), Cu (75.7–92.6 mg/kg), Zn (498–612 mg/kg), and Ni (3.66–4.25 mg/kg). The highest values were observed in June for Cd, Cr, and Zn, at Lanzhou and Tianshui. At Qingyang and Zhangye, the Cd, Cr, and Zn contents were stable throughout the year. There was a similar monthly change among the four cities regarding the levels of Ni content, and it was far below the background value. The monthly fluctuations in Cd, Pb, Cr, and Zn are mainly due to street dust effect. For cities with a developed industry, the impact of street dust during the first rains of the year on sewage sludge’s heavy metal content must be highlighted as being of particular importance.
... The study of PTEs associated with urban dust becomes highly demanded (Acosta et al., 2015;Benhaddya et al., 2016;Dat et al., 2021;Deng et al., 2018;Deocampo et al., 2012;Fedotov et al., 2016;Kelepertzis et al., 2020;Vlasov et al., 2021;Yuen et al., 2012). The spatial distribution, source apportionment, and assessment of risks (environmental, ecological, health) of PTEs in urban dust are the main goals of studies. ...
Potentially toxic elements (PTEs) in urban dust of Moscow megacity and related risks have been studied. 78 samples were collected in the Moscow downtown in sites with different anthropogenic load, namely, major highways, residential area, and recreation zones. The concentrations of PTEs in urban dust were determined by ICP-MS and ICP-AES. Then, environmental, ecological and health risks of PTEs in urban dust were assessed. In addition, potential sources of PTEs in dust were identified. It is shown that Moscow dust is mainly contaminated by Sb, Zn, Pb, Cd, Cu, Sn, and Mo, which according to the data of principal component and correlation analyses can be attributed to anthropogenic sources (non-exhaust vehicle emissions). Potential ecological risk factor demonstrates that Cu, Mo, and Cd have moderate potential ecological risks in 13% of studied area, while Sb has this risk in 62% of area. Potential ecological risk indices indicate that 41% of studied territory is of moderate ecological risk. Concerning the human risks through ingestion, dermal contact, and inhalation pathways, PTEs in Moscow dust have no significant non-carcinogenic risks for adults. However, the value of total hazard index for children is 1.8 showing that non-carcinogenic risks may occur. Moreover, possible carcinogenic risks caused by Cr are evaluated. The finding of the present study can be used for ecological management in the megacity to reduce both ecological and human risks. A special attention should be given to periods of hot and dry weather and to traffic-related emissions.
... The lethality of most heavy metals for humans is estimated in the range of 500-350 mg per day. Heavy metals cause various diseases such as infertility, poisoning, nervous system disorders, breaking chromosomes, premature aging and various cancers in humans [28,128]. Cancer is the main cause of death in developed and developing countries of the world. ...
In the era of industrialization and technological progress, pollution has reduced the quality of life for humans. Heavy metal pollution is one of the main causes of environmental degradation. The underlying causes are natural as well as human. Heavy metal contamination of soil has become a worldwide environmental issue that has attracted considerable public attention, mainly due to increased concern for the safety of agricultural products. Heavy metals refer to some metals and metals with biological toxicity such as cadmium, mercury, arsenic, lead and chromium. These elements enter the soil agricultural ecosystem through natural processes resulting from raw materials and through human activities. Heavy metal pollution is a great threat to the health and well-being of animals and humans due to the risk of potential accumulation through the food chain. The main sources of heavy metal pollution are air pollution, river sediments, sewage sludge and municipal waste compost, agricultural chemicals such as fertilizers and pesticides, and industrial wastes such as factories that release chemicals. Heavy metals can enter the water supply through industrial and consumer wastes or even from acid rain that decomposes soils and releases heavy metals into streams, lakes, rivers and groundwater.
... Heavy metals (e.g., As, Cd, Cr, Cu, Mn, Ni, and Pb) are more likely to accumulate than degrade and can be transferred through the food chain [11]. Sources of heavy metal pollution can be divided into two pollution source categories: point pollution and nonpoint pollution [12]. Examples of point pollution sources include domestic sewage and effluent from factory wastewater treatment systems. ...
To safeguard aquatic environments in and around the Han River watershed in South Korea, a multivariate statistical evaluation of trace elements, a trace element concentration analysis and source determination, and a human health risk assessment were conducted on 10 trace elements at 25 sites. The results demonstrated that the Han River watershed was mainly affected by anthropogenic activities (traffic/industrial activity). The range of concentrations was arranged in descending order: Fe (217.13 ± 301.03 µg/L) > Mn (102.36 ± 153.04 µg/L) > Zn (23.33 ± 79.63 µg/L) > Ba (29.05 ± 12.37 µg/L) > Ni (5.14 ± 11.57 µg/L) > Cu (3.80 ± 3.56 µg/L) > Pb (0.46 ± 0.52 µg/L) > Se (0.06 ± 0.04 µg/L) > Cd (0.01 ± 0.01 µg/L) > Ag (0.004 ± 0.013 µg/L). The hazard index values of trace elements in surface water for combined pathways (ingestion and dermal contact) were < 1.0 for both adults and children, indicating no possible human health hazards. The estimated total cancer risk did not exceed the acceptable limit (1 × 10−4) for adults and children. The findings of this study provide data-driven guidelines for water environment policy decisions in the study area.
... A major source of Pb in the soil is from abrasion of the automobile tires, engine wares, and spills from batteries including the gasoline containing Pb [52]. Besides, the low solubility of Pb allows it to have a long residence time in the roadside soil environment [53]. Cadmium was found to be the least contaminated in soils of all land-uses under the present investigation. ...
Ever-increasing population, rapid urbanization, and industrialization have
critically deteriorated the urban soil quality. This study was conducted to
assess the ecological risk of cadmium (Cd), chromium (Cr), copper (Cu), nickel
(Ni), and lead (Pb) in four different land-use urban soils viz, commercial area
(CA), heavy traffic ring roadside (HT), residential area (RA), and agricultural
farm (AF) of Kathmandu District, Nepal. For this purpose, concentrations of
the five heavy metals (HMs) were determined by using a flame atomic
absorption spectrophotometer (FAAS), in a total of 31 soil samples collected
from all four land uses. Pollution indices such as contamination factor (CF),
degree of contamination (CD), pollution load index (PLI), geo-accumulation
index (I-geo), ecological risk factor (ER), and potential ecological risk (PER)
were used to assess the ecological risk posed by the HMs. The overall mean
concentrations for Cd, Cr, Cu, Ni, and Pb were 0.98, 137.05, 79.80, 100.00, and
72.27 mg/kg, respectively, and were found 2-4 times greater than the
background values. The statistical analysis revealed a poor correlation of the
HMs against pH and total organic carbon (TOC) suggesting little influence on
HMs contamination. Results also showed the highest concentrations of the
HMs in HT soils among the land use types. Ecological risk assessment revealed
CF (0.42-5.06) and CD (7.83-15.72) values as indicators for low to
considerable, and moderate to considerable risks respectively, in soils of all
land uses under the present investigation. Whereas the PLI values (1.12-2.96)
corresponded to the polluted urban soils, the Igeo values (0.08-1.02)
indicated an unpolluted to the moderately polluted class of soil contamination
in all the land-uses. Likewise, the ER (0.91- 114.90) and PER (113.97-170.14)
values pointed out that all the land use urban soils were exposed to a class of
low to considerable, and moderate to considerable risks, respectively. Among
the HMs, Cd, and Pb posed a comparatively high ecological risk for soils of all
land uses and the estimated indices indicated HT as the most vulnerable land
use suggesting immediate control measures.
... The variations were more notable in rural areas than in industrial and residential areas. Since street sweeping may not be efficient in removing fine road dust particles that carry heavy metals (Yuen et al., 2012), reducing heavy metal emissions should be a primary means of controlling heavy metal contamination in urban areas. Tyre and road pavement materials should be investigated to reduce heavy metal emissions due to the interaction between tyres and road surface. ...
Heavy metal contents in road dust have been an important indicator of heavy metal pollution arising from traffic-related activities. In this study, 108 road dust samples were collected from four locations of Hong Kong, namely Kwai Hing (industrial area), Sau Mau Ping (residential area), Sai Kung and Tai Lam (rural area), over a one-year period and analysed for zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), chromium (Cr), cadmium (Cd), and arsenic (As). The geo-accumulation indices (Igeo) and contamination factors indicated zinc, copper, chromium, to a lesser extent, nickel, and cadmium pollution of road dust in industrial and residential areas. The potential ecological risks of Cu were found to be particularly high in both areas. Residential and industrial areas are prone to considerable and very high risks, respectively, based on the risk indices (RI). The sources of heavy metals may vary slightly between the areas based on Pearson's correlation analysis. It was found that the metal contents in the road dust samples vary differently between the dry and wet seasons. The concentrations of Zn were higher in the dry season while those of Cu, Cr and Ni were generally higher in the wet season.
... As pointed out by previous studies, the PTEs in dust were higher in industrial areas than in residential areas; tailing would be a leading contributor to pollution. The smelting process could also make a difference in the composition of tailings (Yuen et al., 2012;Tian et al., 2019). ...
Potentially toxic elements (PTEs) can be released during mining operations and ore processing. The pollution and health risk related to PTEs in total suspended particulates (TSPs) around the largest polymetallic rare earth mining area (Bayan Obo) and smelting area (Baotou) in Inner Mongolia, China, were evaluated. PTEs in the hair of the elderly living in these two areas and a reference area (Hohhot) were also examined. Relationships between PTEs in TSPs and hair with categorical factors (location, gender, etc.) were also modeled. Multivariate statistical analyses were carried out to analyze the possible sources of the PTEs in TSPs. The bubble maps of the concentrations of PTEs indicated that high concentrations of PTEs were near the industrial area where smelting plants and power plants were located. In addition, health risks were assessed for adults in the mining and smelting area. The carcinogenic risk of Cr was high for residents in the study areas. Also, the residents were exposed to a non-carcinogenic risk of Ni. Significant mean value differences were observed between PTEs in the hair of the elderly in Baotou and Hohhot. Results of the linear regression model indicated that around 31 % of the Pb in hair could be explained by the linear regression model, it could be affected by Ni and Zn in TSPs, but location, gender, and sampling time showed no significant contribution. Age was not significantly associated with the PTEs levels in hair in Baotou and Bayan Obo. The results provide important scientific evidence for a better understanding of the effects of PTEs in TSPs in polymetallic ore mining and smelting areas.
... The results of integrated contamination assessment followed the trend of I geo . The PLI values in this study are much higher than that conducted in the road dust of Singapore, Malaysia, and China by Yuen et al. (2012), Wahab et al. (2020), and Fan et al. (2021), and consequently have the potential to severely deteriorate the ecosystem of Dachang mining areas. Road dust comprises of several HMs (Men et al. 2020) and the associated risk is determined in many studies (Shahab et al. 2020;Liu et al. 2019b). ...
Dachang mining area in China is known as “paradise for mineralogists” due to its most reserves of Sn, Sb, Pb, and Zn non-ferrous metal resources; thus, its evaluation for heavy metal assessment and consequent health risk is unavoidable. Sixty road dust samples were collected from study area to explore pollution level, ecological, and health risks from heavy metals and were analyzed by an inductively coupled plasma optical emission spectrometer and atomic fluorescence spectrometer. The results showed that average concentration of all the heavy metals in road dust in both mining and residential areas were remarkable higher than its corresponding background values, the former being more severe, except for Cr and Co. The morphological investigation showed that most of the particles were much less than 100 μm illustrating fine part of the road dust samples. Based on integrated pollution indices, Cd, Sb, As, Zn, and Pb were extremely contaminated and exceeded hundred times of the maximum risk value. The health risk assessment revealed substantially higher carcinogenic and non-carcinogenic risks to children and adult. Highest non-carcinogenic risk resulted from arsenic in mining and residential area with HQing of 644.56 and 267.94 respectively (standard HQ ≥ 1) while carcinogenic risk to children (1.94E + 00) which greatly exceeded from the threshold value of (1.0E-4). Sb, Cd, and Pb also posed carcinogenic and non-carcinogenic risk in road dust which is caused by excessive mining activities and heavy vehicle movement in the study area.
... Cu and Zn are known as wear-generating elements, as Cu can be emitted from the wear of engine parts, fuel, and oil leakage (Hassan, 2012;Yuen et al., 2012), while Zn can be derived from tire abrasion, brake wear, and corrosion of vehicle parts (López et al., 2011). Previously deposited Pb in the soil may be re-suspended in road dust (Taylor and Kruger, 2020;Chen et al., 2019;Jeong et al., 2018;Amato et al., 2014;Chen et al., 2014). ...
The valence state and concentration of metallic pollutants are important
factors contributing to the health effects of respirable particulate matter (PM); however,
they have not been well studied. In this study, coarse and fine powder samples of atmospheric
PM were collected using a cyclone system at Kanagawa (KO), Saitama (SA), and
Fukuoka (FU) in Japan in 2017. Energy dispersive X-ray fluorescence spectroscopy (EDXRF)
was used to measure the concentrations of nine metallic elements (Ti, V, Cr, Mn, Fe, Ni, Cu,
Zn, and Pb), and X-ray absorption fine structure (XAFS) spectroscopy was used to analyze
the valence states of target elements (Cr, Mn, Fe, Cu, and Zn). The EDXRF results indicated
that the average contents of Fe, Ti, and Zn were much higher than those of the other six
elements in all samples. The XAFS results showed that the major valence states of the elements
were Cr(III), Mn(II), Fe(III), Cu(II), and Zn(II). The percentages of Mn(IV), Fe(II), and
Cu(0) were higher in KO and SA samples than in FU samples. Mn(0) and Zn(0) were
detected in some samples only, and Cu(I) was not detected in any samples. Correlation
analysis, principal component analysis, and cluster analysis were performed on the
EDXRF and XAFS data of the target elements. The source identification results showed
that the sources of metal contaminants in the samples varied considerably between
sampling sites and depended on the industrial structure and geographical location of
the sampling area. Our findings on the different valence states of the elements may be
important for determining the toxicity of PM at different locations.
... This environment like similar aquatic systems, provides food and shelter for flora and fauna as well as act as a sink for a wide variety of pollutants (Swarnalatha et al., 2013). Heavy metals among other pollutants have been of great concern due to their abundance, persistence, toxicity and nonbiodegradability (Yuen et al., 2012). Humans may be exposed to the deleterious impact of these metals through direct inhalation, consumption of aquatic organisms (ingestion) and dermal contact absorption (Chabukdhara, and Nema, 2013;Qing, 2015;Silva et al., 2017). ...
Five heavy metals and benthic foraminifera contents in sediments from Lagos Harbour (Nigeria) were investigated,
to determine the degree of contamination and the corresponding impact on the abundance of the benthic species.
Surface-sediment samples were analysed by adopting multi-acid digestion and employing inductively coupled
plasma-emission spectrometer (ICP-MS: MA-300) for metal quantification. Standard preparation for the recovery of
foraminifera was followed, and specimens were identified. The consensus-based empirical sediment quality
guidelines (SQGs); and relevant indices of contamination were used to assess the extent of sediments' degradation.
Results showed that concentrations of metals such as Cu, Pb, Ni and Zn which were below the threshold effects level
(TEL) in sediments are expectedly favourable for benthic foraminifera. Meanwhile, the corresponding low
population density of some species in response to moderate contamination by Zn, indicated that their microhabitats
are impaired, despite the concentrations being below TEL. Four dominant species identified are Hanzawaia boueana,
Textularia sgittula, Florilus atlanticus and Melonis padanum in decreasing order of abundance. Consequent upon the
spurious impact of Zn and As contamination, Textularia sagittula which constituted over 94 % of the agglutinated
forms, were implied to be most disadvantaged among the dominant species.
Keywords: Heavy metals, benthic foraminifera, Hanzawaia boueana, Melonis padanum, agglutinated forms.
... The enrichment factor (EF) approach was utilized to assess the degree of elemental pollution [34]. EF is defined mathematically as: ...
Particle size distribution (PSD) of road dust has significant repercussions on atmospheric pollution by road dust resuspension. The PSD of road dust at a few major commercial, traffic, and residential sites in Kolkata mega city was analyzed in the size range of <28–2000 µm. Predominance of the coarse size range (212–600 µm followed by 106–212 µm) was observed. In size-segregated road dust, Fe (4.02–31.2 g kg−1) dominated other elements and was followed by Mg (2.13–10.9 g kg−1), Mn (79.2–601 mg kg−1), Li (395.8–506.8 mg kg−1), and others. Fine particles (<28 μm) had higher elemental concentrations than coarser ones. Cd and Li showed the highest degree of enrichment compared to the Earth’s crust, but only Cd posed significant ecological risk due to its high ecological toxicity. Individual elements did not post significant non-cancer health risks, except for Li in children. However, the cumulative non-cancer risk from all toxic elements for children was almost four times higher than the acceptable level. Lifetime exposure to carcinogenic elements at the current level may pose 5 to 6 times higher cancer risk in the adult population than the acceptable risk of one in a million.
... This environment like similar aquatic systems, provides food and shelter for flora and fauna as well as act as a sink for a wide variety of pollutants (Swarnalatha et al., 2013). Heavy metals among other pollutants have been of great concern due to their abundance, persistence, toxicity and nonbiodegradability (Yuen et al., 2012). Humans may be exposed to the deleterious impact of these metals through direct inhalation, consumption of aquatic organisms (ingestion) and dermal contact absorption (Chabukdhara, and Nema, 2013;Qing, 2015;Silva et al., 2017). ...
Five heavy metals and benthic foraminifera contents in sediments from Lagos Harbour (Nigeria) were investigated, to determine the degree of contamination and the corresponding impact on the abundance of the benthic species. Surface-sediment samples were analysed by adopting multi-acid digestion and employing inductively coupled plasma-emission spectrometer (ICP-MS: MA-300) for metal quantification
... These sources also can contain different heavy metals (Ferreira Baptista and De Miguel, 2005). It contains various metal concentrations, because of the anthropogenic sources such as traffic (exhaust, tire abrasion, brake lining abrasion), applications of various manufacturing facilities or industries (burning of coal, metallurgical activities, auto reparation plants, chemical manufactures, etc.), and road building (asphalt, concrete, and painting of road) (Yuen et al., 2012;Lu et al., 2009;Adachi and Tainosho, 2005;Bilos et al., 2001;). The deposed dust compounds and their amount are effective and sensitive indicators for the environmental issues in metropolitan areas (Tang et al., 2013). ...
Road dust which is a contamination indicator in the environment may contain high levels of heavy metals, which can continue for a long time in the urban areas causing various problems to living organisms. Heavy metals in urban road dust can originate from many moving and steady sources such as industrial discharges, vehicle releases, atmospheric deposition, and natural geochemical processes in urban areas. In this study, assessment of contamination trace metals is investigated including antimony (Sb), barium (Ba), bismuth (Bi), gallium (Ga), lanthanum (La), scandium (Sc), strontium (Sr), and tungsten (wolfram, W) in Istanbul road dust by using enrichment factor (EF), pollution load index (PLI), contamination factor (CF), and contamination degree (Cd). In addition, statistical methods like correlation and multivariate analysis are used to identify the causative resources of these metals. According to the results of this study, PLI values are higher than 1 for all trace metals. The EF values are also found to be high for Sb, Bi, and W. The CF indicators of trace metals show moderate contamination for Ba, Sr, and Bi, and considerable contamination for W, and a very high contamination factor for Sb. The current findings indicate that anthropogenic activities are the main trace metals’ resource in Istanbul road dust samples.
... Samples were ignited in a muffle furnace (Nabertherm B150) at 550 • C for 2 h. This temperature is commonly applied as the standard temperature for loss on ignition in RDS (Ma et al., 2018;Yuen et al., 2012). The influence of ignition temperature was studied, but no significant difference of LOI with varying temperatures in RDS from 375-600 • C were detected (Gelhardt, 2020). ...
Road-deposited sediments (RDS) contain metals that can pollute receiving waters during precipitation events. The concentration of particle-bound metals tends to increase with decreasing particle size. In terms of metal load, the highest loads were often located in the medium range of particle sizes. Many studies have used varying or undocumented sieving techniques without showing the quality of the separation process. This is important as different particle size classes are documented with different pollution contents and loads. This knowledge builds the foundation for the selection of best management practices to improve receiving water quality. Based on the knowledge that the separation of particle sizes by the commonly applied dry sieving can be methodologically biased, this study compares particle size classes obtained by dry and wet sieving methods. The aim of the study was to show the methodological influence of the sieving process on the particle-size distribution (PSD) with focus on the metal distribution within RDS. Therefore, concentrations of Cu, Zn and Pb were determined and loads were calculated per sieve fraction after wet and dry sieving. Wet sieving causes a shift of the PSD to finer particles and both metal concentrations and loads are significantly higher especially in the smallest sieve fractions. Fine, highly polluted particles remained in coarser sieve fractions after dry sieving. This leads to diverging metal contents and especially loads in the fractions > 250 µm and thus lead to varying conclusions from the results. The results of the comparison of sieving methods however confirmed the relevance of the fine particle fractions in terms of best management practices. The fraction < 40 µm showed highest concentration and load in RDS after wet sieving. The results also showed the considerable influence of the sieving method used and the need to document laboratory methods as part of good laboratory practice.
Heavy metals present a substantial threat to both the environment and human health. Considering the delicate ecological equilibrium of the Tibetan Plateau (TP) and its heightened susceptibility to anthropogenic impacts, scholarly attention has progressively turned toward the examination of heavy metal pollution within the plateau's environment. In this study, we conducted a comprehensive analysis of various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb, and Sb), utilizing topsoil samples collected from the TP during the period of 2018–2021. Additionally, snow and cryoconite samples obtained from TP glaciers during the same timeframe were also subjected to analysis. The results indicate elevated concentrations of total heavy metals in the eastern and western TP (328.7 μg/g), as opposed to the central and southern TP (145.7 μg/g). Most heavy metals exhibit a consistent spatial distribution pattern. High Enrichment Factors (EFs) and Geoaccumulation Index (Igeo) values for As and Cd suggest their enrichment in TP topsoil. Receptor modeling identified three primary sources of heavy metals within the topsoil: industrial sources (42.3%), inherent natural sources within the surface soil (20.6%), and vehicular emissions (14.2%). Substantial differences in heavy metal concentrations and spatial distribution were observed between the topsoil and the glacial snow-cryoconite matrix. The prominent presence of Sb in the snow-cryoconite matrix, in contrast to its low abundance in the topsoil, indicates distinct source influences of long-range transported materials between the two environments. Our inference suggests that the influence of heavy metals from distant pollutants undergo mixing and dilution in the topsoil due to the presence of local indigenous heavy metals, although such influence is notably observed on the glacier surface of the TP. Consequently, this underscores the significant impact of long-range transported sources on heavy metals, surpassing the influence of local TP soils, to the alpine glaciers and even other atmospheric sediments in Tibetan Plateau.
Anthropogenic activities have caused environmental metal contamination in urban areas. Biomonitoring using organisms such as invertebrates can evaluate metal pollution, supplementing chemical monitoring, which cannot comprehensively reflect how metals influence organisms in the urban environment. To assess metal contamination in Guangzhou urban parks and its source, Asian tramp snails (Bradybaena similaris) were collected from ten parks in Guangzhou in 2021. The metal concentrations (Al, Cd, Cu, Fe, Mn, Pb, and Zn) were measured by ICP-AES and ICP-MS. We evaluated the metal distribution characteristics and correlations among metals. The probable sources of metals were determined by the positive matrix factorization (PMF) model. The metal pollution levels were analysed using the pollution index and the Nemerow comprehensive pollution index. The mean metal concentrations were ranked Al > Fe > Zn > Cu > Mn > Cd > Pb; metal accumulation in the snails was ranked Al > Mn > CuFe > Cd > Zn > Pb. Pb-Zn-Al-Fe-Mn and Cd-Cu-Zn were positively correlated in all samples. Six major metal sources were identified: an Al-Fe factor corresponding to crustal rock and dust, an Al factor related to Al-containing products, a Pb factor indicative of traffic and industries, a Cu-Zn-Cd factor dominated by the electroplating industry and vehicle sources, an Mn factor reflecting fossil fuel combustion, and a Cd-Zn factor related to agricultural product use. The pollution evaluation suggested heavy Al pollution, moderate Mn pollution, and light Cd, Cu, Fe, Pb, and Zn pollution in the snails. Dafushan Forest Park was heavily polluted; Chentian Garden and Huadu Lake National Wetland Park were not widely contaminated. The results indicated that B. similaris snails can be used as effective biomarkers for monitoring and evaluating environmental metal pollution in megacity urban areas. The findings show that snail biomonitoring provides a valuable understanding of the migration and accumulation pathways of anthropogenic metal pollutants in soil‒plant-snail food chains.
Sporting walkways are planned features designed to facilitate physical exercise in urban areas. Potentially toxic elements (PTEs) associated with deposited dust (DD) of urban sporting walkways (USWs), suburban sporting walkways (SSWs) and residential sporting walkways (RSWs) in Jeddah, Saudi Arabia, were measured and interpreted in relation to concentration, spatial distribution, pollution level and human health risk. The elemental concentrations followed a similar pattern, but were generally lower than those in road dust. Pb, Zn, Cu, Cd, and As had elevated Crustal Enrichment Factors (>10), ranging up to 185 for Cd. Except for Fe, ∑PTE concentrations were in the following order: USWs (1431 mg/kg) > SSWs (1073 mg/kg) > RSWs (892 mg/kg). Based on the spatial pattern and enrichment factor, and ecological risk values, sporting walkways (SWs) had moderate to heavy pollution levels of Cd, As, Pb, Zn and Cu, and heavy to extreme pollution level of Cd in USWs. Cd presented a high ecological risk, accounting for 85% of the summed ecological risk indices of the elements with elevated concentration. Carcinogenic and non-carcinogenic risks for children and adults follow the order: USWs > SSWs > RSWs. Ingestion was the main pathway for carcinogenic and non-carcinogenic risks, well exceeding that for the dermal and inhalation pathway. Most risks to human health were generally within the acceptable range, although risks to children were generally higher than those to adults, by a factor of 5.5 for non-carcinogenic risk. Incremental Lifetime Cancer Risks for individual elements did not exceed 10⁻⁴ for any element.
Water is the most fundamental requirement for existence on Earth. There is a natural existence of metals in the water resources but various anthropogenic sources have added immensely to an abnormally high concentration of heavy metals. The main concern with these metals is they show toxicity at very low concentration and also associated with environmental degradation, poor water quality, and different human diseases. They bioaccumulates in the plant and animal system over a period of time by entering through food, air, and water. There are mainly two sources of water pollution, point and nonpoint source (NPS). Injudicious use of fertilizer and pesticide in agricultural practices contributes as NPS pollution to water resources through land run off and has been the source of heavy metals. Industries such as leather, paper and pulp, dye, steel, electroplating, fertilizer manufacture, ore processing and others often discharge untreated wastewater loaded with many criteria metals like Pb, Cd, Cr, etc., into the water and contributes to the point source of water pollution. These metals, once they enter the water, begin to accumulate in the food chain. Some metals also bioaccumulate in animal and human system causing various diseases like Minamata, cancer, etc. To control NPS pollution in water bodies, installation of suitable engineering structures can be undertaken in contaminated area to reduce land runoff. The wastewater generated in industrial facilities has to be treated up to WHO recommended limits before its discharge into water bodies.
Background: The objective of this study is to evaluate the effects of traffic on human health comparing biomonitoring data measured during the COVID-19 lockdown, when restrictions led to a 40% reduction in airborne benzene in Rome and a 36% reduction in road traffic, to the same parameters measured in 2021. Methods: Biomonitoring was performed on 49 volunteers, determining the urinary metabolites of the most abundant traffic pollutants, such as benzene and PAHs, and oxidative stress biomarkers by HPLC/MS-MS, 28 elements by ICP/MS and metabolic phenotypes by NMR. Results: Means of s-phenylmercaputric acid (SPMA), metabolites of naphthalene and nitropyrene in 2020 are 20% lower than in 2021, while 1-OH-pyrene was 30% lower. A reduction of 40%
for 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodGuo) and 60% for 8-oxo-7,8-dihydroguanine (8-oxoGua) were found in 2020 compared to 2021. The concentrations of B, Co, Cu and Sb in 2021 are significantly higher than in the 2020. NMR untargeted metabolomic analysis identified 35 urinary metabolites. Results show in 2021 a decrease in succinic acid, a product of the Krebs cycle promoting inflammation. Conclusions: Urban pollution due to traffic is partly responsible for oxidative stress of nucleic acids, but other factors also have a role, enhancing the importance of communication about a healthy lifestyle in the prevention of cancer diseases.
Increasing attention has been paid to antibiotic resistance genes (ARGs) in environments. However, no available literature could be found on ARGs contamination in urban underlying surface sediments. In this study, sediments from commercial public squares around Nanjing (China) were selected for the investigation of target ARGs distribution, showing that intracellular ARGs (iARGs) in particles were the dominant with their relative abundances in descending order of 4.82 × 10⁻² copies/16S rRNA (<0.063 mm), 4.18 × 10⁻² copies/16S rRNA (0.063–0.125 mm), 3.70 × 10⁻² copies/16S rRNA (0.25–0.5 mm), 3.44 × 10⁻² copies/16S rRNA (0.5–1 mm), 3.20 × 10⁻² copies/16S rRNA (0.125–0.25 mm) and 9.53 × 10⁻³ copies/16S rRNA (1–2 mm), which was different with that of extracellular ARGs (eARGs). The influence of street sweeping on ARGs levels indicated that the species and relative abundances for both iARGs and eARGs in sediments from different sites were not consistent with the corresponding population densities. The correlation between ARGs and dominant bacterial communities implied that both Firmicutes and Bacteroidetes were positively correlated with ARGs (P < 0.01). The role of solar UV disinfection demonstrated that UV irradiation could inactivate antibiotic resistance bacteria (ARB) slightly with 0.5–1.0 log reduction, implying a considerable risk of ARB after solar irradiation. Our results suggested that it would need the more effective sweeping modes for the cleaning of small particles (<0.25 mm) and the higher disinfection to ARGs potential hosts (like Firmicutes and Blastocatella).
To investigate the characteristics of heavy metals (As, Cd, Cr, Cu, Pb, Hg, Ni and Zn) in urban road dust from different cities and functional areas in the Pearl River Delta (PRD), South China, a total of 294 dust samples were analyzed. The contamination characteristics and health risk of heavy metals in the dust were assessed, their chemical speciation were distinguished, and their sources were identified by the correlations, cluster and principal component analysis (PCA). The mean concentrations of As (15.89 mg/kg), Cd (1.59 mg/kg), Cr (143.75 mg/kg), Cu (184.42 mg/kg), Pb (114.82 mg/kg), Hg (0.11 mg/kg), Ni (41.53 mg/kg) and Zn (645.94 mg/kg) in urban road dust were in high or moderate levels compare with other previous researches. In this case, the contamination of Cr, Cu, Ni and Zn in the industrial area (IA) and the contamination of Cd and Hg in the commercial area (CA) were significantly higher relative to other functional areas (P < 0.05), and the contamination of heavy metals in Foshan City was significantly higher than other cities (P < 0.01). The order of mobility of the heavy metals with higher concentration in urban road dust of the Pearl River Delta declined in the following order: Zn, Ni, Cu, Pb and Cr. Statistical analysis result showed the contaminated heavy metals in urban road dust were mainly contributed by industrial activities, traffic activities and building pollution. There were no significant carcinogenic and noncarcinogenic risks for adults, children however showed significant noncarcinogenic effect caused by As and Cr in partial points, albeit with low contamination level of the two metals. The ingestion was a principal pathway for heavy metals via urban road dust to exposure population. More protection measures should be considered to reduce children’s exposure to the dust, especially in the CA and IA.
In this study, a total of 26 surface sediments samples were collected from the Liao River estuary wetland, China. The concentration, enrichment factors, potential ecological risk, and source apportionment of potentially toxic metals including Sr, Zn, Cr, Ni, Pb, Cu, and As in different seasons were analyzed. The average concentrations of potentially toxic metals in surface sediments from the Liao River estuary wetland were below the first class of Chinese marine sediment quality standard. There was no significant difference in the concentrations of potentially toxic metals in the sediments collected in June and November. The concentrations of potentially toxic metals in the periphery of the nature reserve were higher than those in the core area of the nature reserve. The average enrichment factors of As, Pb, Cu, Ni, Zn, and Cr were about 1, classified as minimal enrichment. The average enrichment factor of Sr was >2, which corresponds to moderate enrichment. The individual (Er) and total potential ecological risks (RI) of these seven potentially toxic metals were low. The positive matrix factorization model suggested that the potentially toxic metals in surface sediments from the Liao River estuary wetland in June were dominantly from atmospheric deposition, industrial discharges, natural sources, and traffic emission. However, the traffic emission source was replaced by agricultural production and metal smelting activities in November.
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Coal mining contributes to economic development, but has an immense impact on the quality of the environment. Soils near coal mines may get contaminated by the dispersion of coal particles and dust from the mines. Soil samples were collected near an opencast coal mine (OCM) in Dhanbad, India. The enrichment of PTEs in coal mine soils and associated human exposure risks were assessed. Health risk assessment was determined by adopting three exposure routes: direct ingestion, inhalation, and dermal contact. Pollution load index was 2.1 which indicates enrichment of heavy metals potentially toxic elements (PTEs). The enrichment of PTEs of heavy metals decreased in the order Sr > Ba > Be > Cu > Ni > Cr > Pb > Rb > Hg > Co > Cd > Zn > As. Hazard quotient for all these elements was < 1.0, indicating no exposure risk. PTEs in coal mine soils are unlikely to pose potential health risk.
The potential toxic element (PTEs) contamination levels, sources, and exposure risk assessment in road dust (RD) from a typical plateau city in southwest China (Kunming) were conducted in this study. The RD was analyzed to determine the PTEs concentrations using ICP-MS. The enrichment factor (EF), geo-accumulation index (Igeo), and multivariate statistical analysis were employed to assess the pollution levels and source identification of PTEs, respectively. In addition, the health risk model was used to assess human health risks. The results showed that the concentrations of PTEs in each functional area could be arranged as follows: CA>TA>IA>RA. The Igeo of Cu, Zn, and Cd were mostly 1–3, which illustrated moderately to heavily contaminate to these element contaminations in each functional (RA, TA, IA, and CA) based on the EF and PCA analysis that the main sources of heavy metals in RD from Kunming are anthropogenic source (61.8%) and natural source (13.4%). The health risk assessment indicates that chromium has a non-cancer risk for children in RA, whereas no cancer risk was found from the inhalation pathways in this study.
The study assessed the concentration and health hazards of Cd, Mn, Pb, Ni and Zn in 54 road surface dust samples. Heavy metal concentrations descended as follows: Mn > Zn > Pb > Ni > Cd and the concentrations were 316.22, 161.24, 88.76, 22.69 and 0.21. Health hazard assessment showed that the modes of exposure descended in the sequence of ingestion > dermal contact > inhalation for children and dermal contact > ingestion > inhalation for adults. The hazard index for both populations was >1 suggesting susceptibility to non-cancer risks. The carcinogenic risk for Ni and Cd was below 1 × 10⁻⁴ suggesting a negligible risk of cancer for both populations. The study suggests that more research studies on HM contamination in road dusts are to be undertaken in the country to develop HM pollution threshold values in road dusts and to account for pollution in city centers.
The heavy metals of soils around coal waste pile at Taoyuan coal mine (in Anhui province, China) has exceeded provincial’s background values, posing a serious threat to residents in the mine area. Quantitative evaluation on human health risks (HHR) from different sources of heavy metals can determine priority sources and help to reduce risks. Statistics, spatial distribution, and positive matrix factorization (PMF) were applied to identify contribution of sources, and HHR from different sources were quantitatively calculated by combining the HHR with PMF model. In this study, 37 samples were collected from topsoil (0–20 cm) around coal waste pile. Four sources were apportioned as follow: industrial activities (48.37%), transportation (22.44%), natural source (15.44%), and leaching from coal waste pile (13.70%). As for carcinogenic risk, industrial activities was the priority source. Moreover, the noncarcinogenic risk and carcinogenic risk for children were obviously higher than adults, and the main exposure pathway for adults and children was similar, mainly from oral ingestion. The combined model was effective to assess HHR quantitatively from different sources, thereby the outcomes of the study provide a better understanding and suggestions for pollution control and human health from sources.
Research work completed in the mid-1990's suggests that street sweeping programs can be optimized to reduce the pollutant washoff from urban streets significantly. The abilities of several different sweeping technologies to pick up accumulated street dirt at various sites were evaluated. In addition, the expected reductions in average annual washoff loads of various pollutants were simulated using a calibrated Simplified Particulate Transport Model (SIMPTM) for two stormwater sites in Portland, Oregon.
Results suggest that reductions of up to 80% in annual TSS and associated pollutant loads might be achieved using bimonthly to weekly sweeping where parked car interference did not exist.
These results stand in sharp contrast to earlier conclusions dating back to December 1983. At that time, street sweeping was found to be generally ineffective as a technique for improving the quality of urban runoff. This conclusion resulted from the USEPA-sponsored Nationwide Urban Runoff Program (NURP) in which over 30 million dollars was expended in an intensive three-year investigation of urban runoff quality and its control at 28 locations throughout the USA.
Concentrations of Zn, Pb, Cd, Fe, Cr, Cu and Ti were measured in body compartments of the echinoid Diadema setosum and in the silt fraction of surface sediment from eight coral reefs in Singapore coastal waters. Metal concentrations in the echinoid varied with the body compartment analysed and with the site of sampling. Amongst the body compartments studied Zn, Cd, Fe, Cr and Cu were preferentially accumulated in the gonads, whereas Pb and Ti were accumulated mainly in the calcified body compartments. The concentrations of most metals differed according to the reef sampled. A decreasing north-south gradient of metal concentrations was observed in D. setosum populations, correlating to the distance from Singapore. A similar gradient was observed for metal concentrations in sediment. It is suggested that D. setosum could be a valuable bioindicator for assessing heavy metal contamination in coral reef ecosystems of the Indo-West Pacific.
Runoff with contaminated urban soil has an environmental risk to the aquatic environment. An assessment of heavy metals in street dust particles from a small town and their risks to the township stream network were conducted at Yangtze River delta. This assessment is based on measurement of heavy metal contents in dust particles with different particle sizes, river sediments, and suspended solids of urban runoff. The ranges of heavy metal content were 0.8–4.3, 16–380, 69–240, 9.3–350, 9.6–863 and 67–1170 mg/kg dry street dust, for Cr, Cu, Ni, Pb and Zn, respectively. Approximately 63%-71% of heavy metals were associated with particles less than 250 μ m; this particle size accounted for 40% of the total mass of street dusts. Of the five land use areas, the industrial areas had the highest heavy metal level. The smaller particle size fraction has a higher heavy metal content, low density, high mobility in runoff, and thus is a higher risk to the stream network. The topographical and hydrological features of the landscape also influence the transport of the contaminated street dusts to the aquatic environment.
Urban roadside sediments were collected for five months from eleven sites in Seoul Metropolitan City and were examined for spatial and temporal variation of heavy metal composition (Cr, Cu, Zn, Pb, Cd and As). Samples for analysis were treated with 0.1 N HCl for partial extraction and with mixed strong acid (HF + HNO3 + HClO4) for total extraction. Using the normalization of the acid extractable metal concentrations with aluminum (element/Al), two statistical approaches, i.e., two-way ANOVA test and R-mode factor analysis (FA), were performed to examine the major sources of variability in the heavy metal composition. The FA results show that Pb and Cr are strongly dependent on site-specific traffic density, whereas Cu, Cd and Zn vary with site characterization (especially the percentage of metal industry) as well as the temporal amount of precipitation. Arsenic, however, does not show any distinct change. As the roadside sediments are heavily polluted with heavy metals (especially Zn and Cu), the management and disposal of the sediments have to be guided by appropriate environmental measures.
The Earth is an unusual planet in our solar system in having a bimodal
topography that reflects the two distinct types of crust found on our
planet. The low-lying oceanic crust is thin (˜7 km on average),
composed of relatively dense rock types such as basalt and is young
(≤200 Ma old) (see Chapter 3.13). In contrast, the high-standing
continental crust is thick (˜40 km on average), is composed of
highly diverse lithologies (virtually every rock type known on Earth)
that yield an average intermediate or "andesitic" bulk composition
(Taylor and McLennan (1985) and references therein), and contains the
oldest rocks and minerals yet observed on Earth (currently the 4.0 Ga
Acasta gneisses (Bowring and Williams, 1999) and 4.4 Ga detrital zircons
from the Yilgarn Block, Western Australia (Wilde et al., 2001)),
respectively. Thus, the continents preserve a rich geological history of
our planet's evolution and understanding their origin is critical for
understanding the origin and differentiation of the Earth.The origin of
the continents has received wide attention within the geological
community, with hundreds of papers and several books devoted to the
topic (the reader is referred to the following general references for
further reading: Taylor and McLennan (1985), Windley (1995), and Condie
(1997). Knowledge of the age and composition of the continental crust is
essential for understanding its origin. Patchett and Samson (Chapter
3.10) review the present-day age distribution of the continental crust
and Kemp and Hawkesworth (Chapter 3.11) review secular evolution of
crust composition. Moreover, to understand fully the origin and
evolution of continents requires an understanding of not only the crust,
but also the mantle lithosphere that formed more-or-less
contemporaneously with the crust and translates with it as the
continents move across the Earth's surface. The latter topic is reviewed
in Chapter 2.05.This chapter reviews the present-day composition of the
continental crust, the methods employed to derive these estimates, and
the implications of the continental crust composition for the formation
of the continents, Earth differentiation, and its geochemical
inventories.
Most estuaries receive a high heavy-metal input from industries. This is reflected in the relatively high levels found in
numerous estuarine organisms and in sediments. Many indicators have been suggested for facilitating the detection of heavy-metal
pollution, but the problems in using these indicators to evaluate the metal loading of estuaries are considerable. Variations
in species composition, and conditions at different sites, differences in season of sampling, and age of organism, as well
as different metal levels in different parts of the organism, make the interpretation of results difficult. The levels reported
here, similar to those in other unpolluted estuaries, have been used to suggest a baseline concentration for heavy metals
in estuaries. The concept of a baseline is fundamental to the formation of a “Biological Quality Index” and “Pollution Load
Index,” and a formula for such an index is suggested and tested at a preliminary level against published data for an English
and a European estuary.
Marine environmental levels of the metals copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) were measured from sediments collected around 20 coastal locations around Singapore, over a 2-year period. Sediment-size analysis was conducted on sediment samples, and Atomic Absorption Spectrophotometry was used in the analyses of sediment heavy metal concentrations. The levels of heavy metals in marine sediment was largely dependant on sediment particle size, as illustrated by the correlation of sediment size with Multidimensional Scaling (MDS) configurations of sediment metal concentrations. In addition, the proximity to shipping activity, and the release of anti-fouling paint from boats also influence heavy metal concentrations in marine sediments of Singapore.
Concentration and mass loadings of heavy metals adsorbed on sediment from an urban road surface in Beijing were investigated.
The buildup and washoff processes are discussed. Results showed that masses of sediments smaller than 500 μm in diameter varied
from 11.2 to 25.5 g/m2. On average, sediments smaller than 125 μm accounted for 42.9% of sediments smaller than 500 μm in mass. Cd, Cr, Cu, and
Ni were more likely to attach to smaller sediments than bigger ones, compared to Pb and Zn. Mass loading of the sediments
generally increased with antecedent dry periods, but the linear relationship was better for smaller sediments than for bigger
ones. Heavy metal concentrations adsorbed on sediments with diameter less than 40 μm generally decreased more obviously than
those adsorbed on bigger ones after rainfall events.
It has long been known that, in the right concentrations, many metals are essential to life and ecosystems [1–4]; chronic low exposures to metals can lead to severe environmental and health effects. Similarly, in excess, these same metals can be poisonous [5–9]. The main metal threats are associated with heavy metals such as lead, arsenic, cadmium, and mercury. Unlike many organic pollutants, which eventually degrade to carbon dioxide and water, heavy metals will tend to accumulate in the environment, especially in lake, estuarine, or marine sediments [10]. Metals can also be transported from one environment compartment to another [11], which complicates the containment and treatment problem.
Street surface pollution is a source of water and air quality degradation in urban areas. Street sweeping is practiced in most urban areas to remove debris and sediments from roads and to reduce pollutant export to the natural environment. The objective of this study was to investigate the environmental effects of not performing street cleaning in the urban environment. The cites of Berkeley and Oakland in California have an "Opt-Out" Program, which has allowed citizens to opt out of having street cleaning services performed on their streets. The composition of road dusts and sediments on opt-out streets were compared to that of those on streets that are swept. For streets that are swept, the before and after effect of street sweeping was also examined. Samples of road sediments were collected from street surfaces and analyzed for metal and polyaromatic hydrocarbon (PAH) pollutant loads. Pollutant levels on road surfaces were found to be site specific. Some opt-out streets have distinctly higher levels of sediments and/or pollutants, while others do not. Discontinuation of the Opt-out Program will likely contribute to some reduction in road surface pollutants, but not to a large extent. Though there does seem to be some environmental concern associated with the Opt-out Program, there is no immediate need to discontinue it.
Samples of common grass collected in the vicinity of a motorway were analyzed by ICP-MS in order to identify some elements showing a concentrational increase in parallel to Pt (years 1992 – 1994). The amounts of Al, Ce, La, Nd and Zr increased significantly within the sampling period and were recognized to be part of automobile catalyst emissions. Concentrational behavior of Ce and its relation to Pt were investigated in detail. Conditions for the prediction of Pt concentrations from a corresponding Ce distribution are reported. It is shown that Pt detected along streets should be attributed to catalyst emissions.
Although street sweeping is commonly regarded as a cost-effective storm-water best management practice, there is little quantitative evidence that street sweeping directly improves runoff water quality. In this paper, several previous street sweeping studies were reevaluated using statistical power analysis. Two-group, independent-sample one-sided t-test power analyses were performed using log-transformed event mean concentrations (EMCs) of total suspended solids, suspended sediment concentration or chemical oxygen demand. The effect size between the two groups was estimated using the sweepers' pickup efficiency, which showed that the failure to detect the difference between mean EMCs of the two sample groups (i.e., unswept and swept groups) is likely due to limited sample numbers. Too few samples, which also resulted in a high coefficient of variation, were analyzed to detect the likely difference between swept and unswept observations. In addition, the temporal gap between street sweeping and subsequent storm events was not controlled to improve statistical power.
Samples of sediment found on an urban road in Aberdeen (Scotland) were collected by washing designated surfaces. This method, called the "wet" method, was capable of collecting sediment of the smallest particle size range that is normally left behind by traditional sampling techniques using dry vacuuming. Over 17 months (mainly on a weekly basis), 66 samples were collected and analyzed for sediment loading, particle size distribution, concentration of heavy metals (Zn, Cu, Pb, Cd) in four sediment size fractions, and several dissolved pollutants in the effluent collected from washing (NO3-, SO42-, PO43-, Cl-, F-, NH4+, total organic carbon, total carbon). Standard statistical methods, including multiple regressions, were used to determine relationships amongst different sediment characteristics. It was found that sediment loading, as well as concentrations of Cl- and SO42-, were highest in the winter months, 4 especially when snow was present on the road surface. It was observed that 66% of total road sediment loading was found within a 0.5 m strip next to the curb. The average sediment particle sizes found were smaller than those previously recorded in the literature. As expected, the concentrations of heavy metals were highest in the smallest particle size fraction analyzed (<63 mum), and this occurred during the summer months when less sediment was available on the street surface. The antecedent dry weather period had a very weak and negative influence on the loading rate of the smallest particle size fraction next to the curb.
A study of oil and grease in urban stormwaters was performed on a small watershed in Richmond, Calif., with the objective of determining the amount of oil and grease discharged into San Francisco Bay. Five sampling stations were selected at various places in the watershed that were indicative of specific land uses, and runoff from seven storms was sampled and analyzed. The results of the survey indicated that oil and grease concentration was highly dependent upon land use, ranging from 4.1 mg/L in residential areas to 15.3 mg/L in parking lots. A statistical analysis of oil and grease and storm characteristics showed that oil and grease concentration was independent of all storm characteristics, except that mass of oil and grease discharged was proportional to total rainfall. Qualitative analysis of the oil and grease by gas chromatography indicated that it most resembled used automobile crankcase oil. Several samples showed evidence of spills of specific compounds. A simulation of management techniques indicated that a 90% reduction in discharge from commercial properties and parking lots, which represented only 9.6% of the total surface area, would result in a 53% reduction in total oil and grease discharge. Growth simulation predicted a potential 27% increase in discharge if 5% of the watershed were converted from open land to commercial property.
Thirty-eight core sediment samples were recently collected from different locations of the Singapore coastal region. The aim of the project was to trace the history of marine pollution in various coastal regions and to determine the impact of industrial activities. Two nuclear analytical techniques were employed in this study: particle induced X-ray emission (PIXE), Rutherford backscattering (RBS) as well as X-ray fluorescence (XRF). Combined together these techniques provide an excellent tool to determine elemental concentrations of more than 30 elements with detection limits as low as few ppm. Our results show that elemental concentrations in most of the regions do not show a significant variation with depth. However, in regions where industrial and shipping activities are high, for example the Port of Singapore area and the northern part of Johore Straits, the concentrations of metals like Cr, Ni, Cu, Zn, Sn and Pb were found to have an obvious decreasing trend with the depth. In these cores, concentrations in the top 10–15 cm were sometimes ten times higher than the corresponding base line concentrations. Elemental depth profiles of Ni, Cu, Zn, As, Sn and Pb and their mean concentrations in various regions are reported and discussed.
This paper investigates the sources of antimony (Sb) in municipal/industrial waste and the consequences of the pres ence of antimony in the input of waste.The average Sb con centration of the feed stream to waste incinerators is approx imately 42 mg/kg. More than 50% of the antimony originates from all types of flame retardants and approximately 35% comes from flame retardants used in consumer electrical and electronic equipment. There is a tendency to decrease the application of halogenated products (and thus of antimony) in flame retardants. Also, the other fields of application of antimony show a decreasing trend. There are no indications that a substantial increase of the concentration of antimony in the feed to municipal waste incinerators will occur in the near future. During the incineration process, the antimony compounds are only found in the bottom ash and fly ash. No volatile Sb compounds are present in the flue gas. This means that efficacious particle removal systems are sufficient for a complete Sb removal during incineration.
To evaluate the capability of calcareous desert soils to minimize the migration of lead (Pb) from Pb‐containing aqueous solutions, soil from six Saudi Arabia sites were filtrated with Pb‐containing municipal solid waste (MSW) landfill leachate. Leaching continued until Pb breakthrough occurred (C/Co = 1) or 7 months’ infiltration if breakthrough did not occur, usually several hundred PVD. The effluent from (5 × 10 cm) soil columns was analyzed for selected metals and pH. Lead was strongly attenuated by all soils. Lead appeared in the effluent only after influent Fe attained a breakthrough. Calcium was negatively attenuated. Only Onaiza sand and Buraida sand reached their maximum Pb‐holding capacity (i.e., a complete Pb breakthrough). As a result of removing the soil from the columns in 2‐cm segments, lead was found to be almost evenly distributed throughout the columns. A dominant fraction of the attenuated Pb was readily extracted by 0.1 N HCl. The attenuation data behaved according to the Freundlich and the Langmuir adsorption isotherms, suggesting the prominence of Pb sorption over other mechanisms. Kharj sand and Quatif sandy loam retained the highest quantity of Pb, though allowing some to pass through, thus indicating multiple reactions of sorption, precipitation, chelation, and organic complexation. This was demonstrated by nonconformity of the data to normal Freundlich or Langmuir isotherms. Hasa and Deerab loams retained all the Pb of the 0‐ to 2‐cm layer. Only 11% was acid extractable.Attenuation was correlated mostly with particle size and lime. The following regression equation (R = 0.967) roughly estimates how far aqueous Pb‐bearing solutions will migrate through these six arid‐land soils: Z = Pb retained, as percent of the total addedC = clay + percent siltY = percent CaCO3 + percent CaSO4Thus the longevity of Pb occlusion appears to be related to the migration and/or de sorption of CO3 in the soil system.
A preliminary study on heavy metals pollution in the vicinity of Kuala Lumpur city, Malaysia was carried out by analyses of soils and streetdust. The distribution of the metals in the “easily or freely leachable and exchangeable”;, “oxidisable organics”;, “acid reducible”; and “resistant”; fractions were determined by a sequential extraction technique. The result reveals a markedly high metals pollution in the city with > 98% of Pb level contributed from the surrounding environment. Pb, Zn and Mn were found to be highly soluble in the the non‐resistant fraction.
More than 100 organic compounds are quantified in these samples, including n-alkanes, n-alkanoic acids, n-alkenoic acids, n-alkanals, n-alkanols, benozoic acids, benzaldehydes, polyalkylene glycol ethers, PAH, oxy-PAH, steranes, hopanes, natural resins and other compound classes. Paved road dust acts as a repository for vehicle-related particles, which can then be resuspended by the passing traffic. To evaluate the contributions from major urban sources to the road dust complex, source profiles representing different types of vehicle exhaust, brake dust, tire debris, and vegetative detritus are compared, and their fractional contributions are estimated using several groups of organic tracer compounds. -from Authors
The chemical speciation of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in marine sediments from two coastal regions of Singapore (Kranji in the NW, and Pulau Tekong in the NE) was determined using the latest version of the 3-step sequential extraction procedure, as described by the European Community Bureau of Reference (1999). To obtain a mass balance, a fourth step, i.e., digestion and analysis of the residue was undertaken using a microwave-assisted acid digestion procedure. The total content of all metals except for Pb in sediments was greater in Kranji than in Pulau Tekong. All metals, except Cd were more mobile and bio-available in Kranji, where metals were present at higher percentages in the acid-soluble fractions (the most labile fraction). In sediments from Kranji, the mobility order of the heavy metals studied was Cd > Ni > Zn > Cu > Pb > Cr, whereas sediments from Pulau Tekong showed the same order for Cd, Ni, Pb and Cr, but had a reverse order for Cu and Zn (Cu > Zn). The highest percentages of Cr, Ni and Pb were found in the residual fractions in both Kranji (78.9%, 54.7%, 55.9%, respectively) and Pulau Tekong (82.8%, 77.3%, 62.2%, respectively), meaning that these metals were strongly bound to the sediments. Results are consistent with findings from Barcelona, Spain where similar results for Cr and Ni have also been reported for marine sediments. The sum of the 4 steps (acid-soluble + reducible + oxidizable + residual) was in good agreement with the total content, which implies that the accuracy of the microwave extraction procedure in conjunction with the GFAAS analytical method is assured.
Roads play a major role intransporting sediment associated nonpoint sourcepollutants to urban stream networks via storm drains. In urban areas the relationship of erodible soil toroads may be of critical importance in controllingmetal contributions to roads. Two 50-m transects(Park and School) were investigated perpendicular toroads in Manoa basin, Oahu, Hawaii. Concentrations ofnine elements were compared to background control soillocations and to five supplemental samples from nearbyrecreational parks. Sediment from curbside areas ofroads (road deposited sediment) was collected as thestarting point of each transect, and subsequently soilwas sampled from two depths (0–2.5 cm and 7.5–10.0 cm)along the transects. Total and 0.5 M HCl extractableconcentrations were determined for aluminum (Al),calcium (Ca), chromium (Cr), copper (Cu), iron (Fe),manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn)using either inductively coupled plasma-atomicemission spectroscopy (ICP-AES) or flame atomicemission spectroscopy (FAAS). Ca, Cu, Pb and Znexhibited anthropogenic enhancement, with Pb and Znhaving the greatest enrichment in road sedimentfollowed by locations nearest the road. Copperdisplayed a narrower band of contamination than eitherPb or Zn, and this may reflect larger aerosolassociations and more rapid fall velocities. Lead andZn exhibited substantial decay in concentration at 50 m compared to the road sediment, but enrichment wasstill apparent. The positioning of a band of soilbetween the road-curb area and the sidewalk for thePark transect facilitated deposition and storage oftrace metals, and with subsequent erosion by splash orconcentrated flow this area can account for continuedtransport of contaminated sediment to adjacent roadsurfaces. On the other hand the School transect hadno soil directly beside the road, and the nearestsample from the road (5 m) displayed enrichment butsubstantially lower than the Park transect. Thesepreliminary data suggest that remobilization of soilstored metals in close proximity to roads cansignificantly prolong the environmental contaminationof urban road systems and eventually stream sediments.
The concentrations of 12 trace metals (Al, Cd, Cr, Cu, Co, Fe,Mn, Ni, Pb, Zn, V, and Ti) in wet depositions are reported. Eighty four rainwater samples were collected using an automated wet-only sampler in Singapore for one year (2000) and subjected to chemical analysis using ICP-MS. Based on the volume-weighted meanconcentrations measured, the trace metals were classified into three groups: Al and Fe with an average concentration of largerthan 15 g L-1, Cr, Cu, Mn, Ni, Pb, Zn, V, and Ti withconcentrations between 1 and 10 g L-1, and finally Co and Cd with concentrations lower than 1 g L-1. Elementenrichment factors were calculated to distinguish between naturaland anthropogenic sources. The calculation of crustal enrichmentfactors with Al as the reference element indicated that while Ti,Fe and Mn originated from crustal sources, the remaining trace metals (Cd, Cr, Co, Cu, Ni, Pb, Zn and V) were mainly derived from anthropogenic sources. The removal of the trace metals from the atmosphere by precipitation was influenced by the rainfall amount as well as pH. The magnitude of the measured average annual wet deposition fluxes of Al, Fe, and combustion-generatedelements such as V, Ni, and Cu is higher than that reportedfor other sites outside Singapore, owing to abundant rainfallthroughout the year in this region.
Incineration has become one of the principal methods for municipal solid waste disposal particularly in all large cities throughout the world. Currently, the municipal solid waste incinerator fly ashes (MSWIF) are disposed of by landfill. The metal speciation of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) in MSWIF after been extracted with water at different pH values were examined using a sequential extraction procedure. The extraction sequence was as follows: (1) Exchangeable (NaOAc, pH 8.2), (2) Bound to Carbonates (NaOAc, pH 5.0), (3) Bound to metal oxides (HONH3Cl), (4) Bound to organic matters (HNO3, H2O2), and (5) Residual (HNO3, HCl, H2O2, HF, 1:3:1:3). The heavy metal contents in the extraction solutions were determined by inductively coupled plasma atomic emission spectrometry. The heavy metal concentrations in the different fractions obtained by sequential extraction show distinct distribution trends. The extractable fraction ranges from 25.5 to 88% of the total element content. With the pH of the extractant fall below the neutral and acidic ranges, the concentrations of heavy metals rise substantially due to the released of metals bound to carbonate fraction.
The use of pressure feedback microwave digestion technique has permitted rapid and efficient digestion of soil and sediment samples. The evaluation of different acid mixtures to digest soil samples were studied by mixed-level orthogonal array design. The selected acid mixture of HCl-HNO3-HF was employed in the survey of Pb, Zn, Cu, Cr and Mn in soil samples. Surface soil samples were collected from industrial, residential and nature reserve areas in Singapore. The five metal concentrations were determined by flame atomic absorption spectrometry and graphite furnace atomic absorption spectrometry. The lead and other metal contents in NBS SRM 1645, NIES CRM No. 2 and NRCC BCSS-1 sediment standard references were determined concurrently with the survey samples. Five measured metal loading on the surface soils was in the order: industrial area > residential area > nature reserve area. The trace metal concentrations in surface soil from areas of heavy traffic are higher than those from residential areas. The main sources of trace metal pollution are vehicular exhaust and industrial activities.
The concentrations of heavy metals in bottom sediments from urban receiving waters, Kranji Reservoir and MacRitchie Reservoir in Singapore, were investigated. Distribution of the heavy metals in the bottom sediment, interstitial water and overlying water was analysed. The concentration of heavy metals in the interstitial water was found to be significantly high and exceed the water quality criteria by three to eleven times. The partitioning coefficient shows that the solubility of the metals are in the order: Mn > Zn > Cu > Pb > Fe > Al. Fractional composition of heavy metals in the sediments was determined using sequential extraction process. The results show that Cu was largely complexed by organics, 74% of Zn was in easily remobilised fractions, and 36% of Pb was in the easily reducible fraction and 47% in carbonate and ion-exchangeable fractions. Release of sediment-bound metals was studied. The results indicate that, besides pH and redox, the sediment buffering capacity is an important parameter affecting the remobilization of heavy metals from sediment.
This chapter gives an overview of sources, transport pathways and targets of road and traffic contaminants. Pollution sources
include traffic and cargo, pavement and embankment materials, road equipment, maintenance and operation, and external sources.
Heavy metals, hydrocarbons, nutrients, particulates and de-icing salt are among the contaminants having received the greatest
attention. Runoff, splash/spray and seepage through the road construction and the soil are major transport routes of pollutants
from the road to the environment. During their downward transport through road materials and soils, contaminants in the aqueous
phase interact with the solid phase. In saturated media, diffusion, advection and dispersion are the major processes of mass
transport. In unsaturated soil, mass transport strongly depends on soil-moisture distribution inside the pores. Sorption/desorption,
dissolution/precipitation and ion exchange reactions are the most significant chemical processes governing pollutant transport
in soils. Redox conditions and acidity largely regulate heavy-metal mobility. Many heavy metals are more mobile under acidic
conditions. Plants close to heavily trafficked roads accumulate traffic pollutants such as heavy metals. Heavy metals, organics,
de-icing salt and other toxic substances disturb biological processes in plants, animals, micro-organisms and other biota
and may contaminate water bodies and the groundwater. European legislation puts strong demands on the protection of water
against pollution. Road operators are responsible for ensuring that the construction and use of roads is not detrimental to
the quality of natural waters.
To investigate the dynamic characteristics of total suspended solids (TSS) and their particle-bound heavy metals in a first
flush, the runoff sampling together with its flow rate measuring was conducted for three rainfall events at outfalls of highway
in Shanghai from June to September 2007. Field samples were analyzed to determine the concentrations of TSS and particle-bound
heavy metals, such as Zn, Pb, and Cu. Results show that the wash off behavior of TSS under varying runoff rate condition can
be explained by different antecedent dry weather period (ADWP). Contribution of fine fraction (<45 μm) to TSS was generally
higher than that of coarse fraction (>45 μm). When the runoff flow increased obviously, a significant contribution of the
coarse fraction was observed for a certain rainfall events with long antecedent dry weather condition. The changes of total
metals concentration and particle-bound metal concentrations were strongly dependent on the TSS variation. TSS was generally
well correlated with most particulate-bound heavy metals. Of the heavy metals, the concentration of Zn was found considerably
high and that of Pb was significantly low at North Zhongshan 2 Road, in Shanghai, China, but they are still within the range
reported in the literature. Fluctuation of heavy metal contents in the coarse fraction during a first flush period was more
significant compared with that in the fine fraction. The results will assist in the development of effective control strategies
to minimize heavy metals and solids in highway runoff.
Anthropogenic contributions of lead to the urban environment havebeen dominated by combustion of leaded gasoline. A number of studies have used lead concentrations in road deposited sediments(RDSs) to infer automobile contributions. However, few studies have combined concentration data, enrichment ratios, and lead isotope ratio data into a comprehensive picture of lead contamination of road sediments. An urban, non-industrialized basin, in Oahu, Hawaii, was selected for investigation. Twenty RDSsamples were collected throughout the 11 km2 system, with anundisturbed soil profile sampled to a depth of 30 cm to documentbackground lead levels.Median lead concentrations from a weak (cold) HCl digestion and a hot nitric acid digestion were 3 and 7 mg kg-1 for thebackground soil, and 256 and 303 mg kg-1 for RDSs. The median Pb enrichment ratio (HCl digestion) for RDSs was 129, witha range from 24 to 883. All the data collected point to a highlycontaminated environment.Lead isotope ratios from potential sources were examined relativeto those observed for RDSs in the system. Host geological rocks,paint, and long-range aerosol transport were ruled-out as significant sources based on an examination of isotope ratios andpotential loadings to road sediments. Leaded gasoline wasidentified as the major contributor to present-day road sedimentsbased on their radiogenic nature, with mean 206Pb/204Pb = 18.787 0.096 (95% confidence interval), 207Pb/204Pb = 15.847 0.074, 208Pb/204Pb= 38.836 0.221, and 206Pb/207Pb = 1.184 0.009. The contribution of gasoline additives to RDS for two periods, pre-1968 and post-1968, were estimated using 206Pb/207Pb ratios. The average contribution of post-1968 lead to RDSs was 59%, with a range from 32 to 81%. To explain the mixed age of lead in the RDSs, we suggest that erosional processes have mobilized sediment from roadside reservoirs in the basin that have accumulated automobile emissions primarily since the 1930s. The significant shift in useof radiogenic (J-type) ores, mostly from Missouri, USA, have allowed us to fingerprint and apportion lead in RDSs of thissystem.
Airborne antimony was sampled in two fractions of particles by a dichotomous sampler (dichot. fine mode and dichot. coarse mode) at two locations in Munich with different traffic impact. Parallel to the sampling of airborne dust, antimony was determined by two standard methods according to VDI-guidelines. Sampling of ‘total deposition’ (wet and dry) was achieved according to the Bergerhoff method (VDI, 1972) [VDI. Guideline 2119, part 2, measurement of dustfall. Bergerhoff instrument (standard method). In: VDI. Handbuch der Reinhaltung der Luft, 1972] and active biomonitoring was performed by exposure of standardized grass cultures (VDI, 1991) (VDI. Guideline 3792, part 3, measurement of the response dose. Measurement of the response dose of ambient lead in plants with standardized grass cultures. In: VDI. Handbuch der Reinhaltung der Luft, 1991). The highest airborne antimony concentrations of 14.0 ng/m (median) were found in close vicinity to traffic, with a maximum enrichment of 11.3 ng/m on particles of the dc-mode [aerodynamic diameters (dae) 2.5 μm ≤dae≤10 μm]. Antimony enrichment near traffic was confirmed by monitoring with standardized grass cultures and total depositions. Results of grass and deposition analysis after nitric acid digestion and subsequent digestion with hydrofluoric acid were compared. They illustrate that the second digestion step produced an increasing effect only on antimony concentrations in grass. Further, antimony on df-mode particles (dae ≤ 2.5 μm) correlated significantly positively with antimony deposition near traffic (significance level, α = 0.05, r = 0.786). These results suggest that the metal compounds of traffic-derived antimony in the two matrices might be different.
Effectiveness of street sweeping and washing (S/W) for controlling ambient “total suspended particles (TSP)” was evaluated by TSP measurements and determining silt load from active traffic streets. A modified regenerative-air vacuum sweeper (RAVS) and a washer were used in this study. The sweeper made a pass followed by the washer. The S/W efficiencies (ηs,ηT) were obtained based on the experimental data of silt loading and TSP. It was found that the direct impact of sweeping on ambient TSP emissions was short-lived lasting no more than 3–4 h. When a vacuum sweeper and a washer, respectively, did a good job collecting or cleaning the visible fine particles on roads, the method of S/W tested in this work was effective at removing the sources of the road dust particles. This paper concludes that street sweeping followed by washing was found to offer a measurable reduction in TSP emission potentials. Typically, the reduction efficiency of ambient TSP is up to 30%. Finally, correlated with ηS (based on silt loading), a useful equation is proposed to estimate the S/W efficiency, ηT (based on TSP) with a standard error of ±20%. It seems feasible to predict the reduction efficiency of ambient TSP controlled by the regenerative-air vacuum sweeper and washer used in this work for engineering applications. Effects of traffic volume and wind velocity on the S/W efficiencies are also discussed in the paper.
Studded tyres cause extensive wear of road surfaces during winter producing small particles. Besides transporting different adsorbed pollutants these particles also discharge metal ions by their own natural content. The major part (95%) of the asphalt is composed of stone fractions. The rest consists mainly of bitumen, which contains trace quantities of metals. Laboratory studies in this study have demonstrated different adsorbing properties of metal ions, as well as differences in adsorption when comparing stone materials. Two stone materials, a gabbro and a porphyry, have been tested for their adsorption properties concerning Pb, Cu, Zn and Cd. The gabbro showed better adsorption capacity than the porphyry. Gabbro has coarser grains, it is softer, and also has a higher content of most metals compared to the porphyry. In all tests lead and copper are more adsorbed than zinc and cadmium. All metal ions are released at about the same pH (≈4).
An understanding of pollutant characteristics on impervious surfaces is essential to estimate pollutant washoff characteristics and to design methods to minimise the impacts of pollutants on the environment. This paper presents data on surface pollutant characteristics on an urban road surface in Melbourne, Australia, from samples collected over a 36 day period. The data indicate that buildup over the dry days occurs relatively quickly after a rain event, but slows down after several days as redistribution occurs. The surface pollutant also becomes finer over the dry days as it is disintegrated. The washoff of surface pollutant is dependent on the rainfall and runoff characteristics, but the results here show that common storms only remove a small proportion of the total surface pollutant load. The data also show that street sweeping may have an adverse impact on pollutant washoff because the street sweeper releases the finer material but only removes some of them, making the fine sediment available for washoff by the next storm. The data also show that most of the nutrients are attached to the finer sediments, and to effectively reduce nutrient loads in particulates, treatment facilities must be able to remove the finer particles (down to 50 μm for TP and down to 10 μm for TN), and not just the total sediment or suspended solid load.
Fly ash from a municipal solid waste (MSW) incinerator in Singapore was physically and chemically characterized. The very fine amorphous ash particle was found to have a non-porous structure with a low specific surface area and a tendency to agglomerate. Chemical analysis indicated that a significant amount (2000–20,000 mg/kg) of toxic heavy metals, such as Al, Pb and Zn were present in the fly ash. Bioleaching using the fungus Aspergillus niger was carried out at different pulp densities of fly ash (1–8%, w/v), and results were compared with chemical leaching using various organic and inorganic acids. Although the fungus grew only in the presence of 1–2% (w/v) fly ash when it was incubated together with the fly ash (one-step bioleaching), growth was observed even at 4% (w/v) fly ash when the ash was added after 2 days of fungal incubation (two-step bioleaching). Both one-step and two-step bioleaching experiments showed similar metal extraction yield for 1% (w/v) of fly ash pulp density (80–100% for Al, Mn and Zn; 60–70% for Cu and Pb, and about 30% for Fe). Optimum pulp density for bioleaching was observed at 1% (w/v), and leaching efficiency decreased with increasing pulp density in fungal bioleaching as well as in spent medium leaching. The main lixiviant in bioleaching was shown to be gluconic acid, which was produced only in the presence of fly ash (in one-step and two-step bioleaching). Compared with chemical leaching at 1% pulp density, the fungus was more efficient in the leaching of Mn and Zn, and showed similar extraction yield for Al. However, Cu extraction yield was lower in bioleaching than chemical leaching. These results suggest that bioleaching by A. niger may be an alternative or adjunct to conventional physicochemical treatment processes of MSW fly ash to remove hazardous heavy metals. Bioleaching mechanisms are also discussed.
Urban air quality is generally poor at traffic intersections due to variations in vehicles’ speeds as they approach and leave. This paper examines the effect of traffic, vehicle and road characteristics on vehicular emissions with a view to understand a link between emissions and the most likely influencing and measurable characteristics. It demonstrates the relationships of traffic, vehicle and intersection characteristics with vehicular exhaust emissions and reviews the traffic flow and emission models. Most studies have found that vehicular exhaust emissions near traffic intersections are largely dependent on fleet speed, deceleration speed, queuing time in idle mode with a red signal time, acceleration speed, queue length, traffic-flow rate and ambient conditions. The vehicular composition also affects emissions. These parameters can be quantified and incorporated into the emission models. There is no validated methodology to quantify some non-measurable parameters such as driving behaviour, pedestrian activity, and road conditions
Limited data are available in the literature on the partitioning of interrill erosion into splash and wash components. Laboratory rainfall simulation experiments were conducted on an Oxisol at 5, 10 and 20° slopes at a constant rainfall intensity. Rainwash was separated from front splash and lateral splash using a novel experimental design. Results indicate that output of sediment from the 0.18 m2 erosion plots was dominated by splash with a geometric mean aggregate diameter (GMAD) similar to that of the original soil. The most easily detached aggregate size by splash was 500 to 1000 μm, i.e., coarse sand-sized aggregates. Wash was dominated by aggregates with a GMAD significantly finer than the soil matrix, and this reflected the limited energy available to transport coarse aggregates detached by splash. Wash and splash sediment flux, and the runoff coefficient increased significantly with slope angle. Peak front splash was associated with a different dimensionless water depth (DWD) for each slope angle. As slope angle increased the DWD at peak output increased from 0 to 0.4 at 5°, and from 1.4 to 1.7 at 20°. Time trends of front splash output for 5 and 10° slopes were similar to those presented in the literature. However, data for the 20° slopes were more complicated, with a series of pulses related to periodic migrating waves of wash sediment superimposed on the general pattern. These migrating bedload waves are interesting in that they seem analogous to those documented in the fluvial environment at steady or even decreasing discharge. Data indicate that front splash flux exceeded wash transport on all slopes tested. These data reflect the boundary conditions of the experiment, but may be applicable under certain field situations, such as on short, steep, furrow side-slopes.
Street surfaces are both sources of urban runoff pollutants and pathways for the transport of pollutants originating from adjacent land areas. This view has led to the suggestion that street sweeping may be a valuable best management practice (BMP) for the control of urban runoff quality. Initial investigtions beginning in the early 1970's indicated that changes in street sweeping practices could be beneficial in reducing urban runoff pollution. In response to this early research, the U.S. Environmental Protection Agency sponsored Nationwide Urban Runoff Program adopted a broad-based assessment of street sweeping as one of its central research elements. The key finding of street sweeping research to date is that as a general, broad-based water quality best management practice it does not appear to be effective in reducing end-of-pipe urban runoff pollution loads. Under favorable conditions, reduction of about 30 percent can be expected, but more typical performance is in the 10 to 30 percent range. For certain constituents such as lead, where street surfaces are the overwhelming sources, street sweeping can control well of 50 percent of the loads. There are other specific condition where street sweeping can be effective.
We report the results of a study of the geochemistry of sediments of the Strait of Johor between the southern tip of peninsular Malaysia and the island nation of Singapore. This shallow channel in the continental shelf connects the South China Sea to the east with the Strait of Melaka to the west. We analyzed sediment layers collected at 25 locations along the east-west axis of the Strait, from the estuary of the Johor river at its eastern end to the estuary of the Pulai river at its western end, using a box corer to minimize disturbance of surficial layers.
Antimony is ubiquitously present in the environment as a result of natural processes and human activities. It exists mainly as Sb(III) and Sb(V) in environmental, biological and geochemical samples. Antimony and its compounds are considered to be priority pollutants interest by the USEPA and the EU. In this first review paper on antimony occurrence in natural waters, 420 papers on freshwaters, marine waters, estuaries, soils, and sediments have been reviewed. All data are quoted from the original sources. Typical concentrations of total dissolved antimony are usually less than 1.0 μg/l in non-polluted waters. When redox speciation determinations are performed, most studies report the dominance of Sb(V) under oxic conditions. However, the presence of significant proportions of Sb(III) is sometimes detected. This is in contrast with thermodynamic equilibrium predictions and discrepancies are often attributed to biological activity or kinetic effects but proofs are lacking. Similarly, the existence of Sb(V), although not thermodynamically predicted, is often reported under anoxic conditions. Low concentrations of methylated antimony species are mentioned in a few studies. Antimony is not considered to be a highly reactive element in oceans, with concentrations of the order of 200 ng/l. In estuarine waters, both conservative and non-conservative behaviours are reported depending on the estuaries' characteristics. Elevated concentrations of antimony in soils and sediments are either related to anthropogenic sources or associated with high arsenic concentrations in sulfidic ores. Antimony appears to be highly unreactive in soils. Low accumulation factors are reported in algae. Airborne supply of antimony to aquatic and terrestrial systems seems to be important in systems far from direct pollution sources. However, the limited available data do not allow firm conclusions to be drawn on the reactivity and cycling of the element in natural systems and a list of research priorities is given.
This paper discusses the main characteristics of the solution chemistry of antimony in relation to its behaviour and fate in natural waters. It is based on a careful and systematic examination of a comprehensive collection of solution equilibrium and environmentally oriented studies, some published more than 100 years ago. General principles are outlined and main unknowns highlighted. Existing information on antimony reactivity in solution is scarce and often relatively old. Studies performed under conditions relevant to natural water conditions are particularly scant.
Twenty-six elements have been determined in street dust from London (U.K.), New York (U.S.A.), Halifax (Canada), Christchurch (N.Z.) and Kingston (Jamaica). The cities divide into two groups, London and New York (large urban) and Halifax, Christchurch and Kingston (small urban). The elements fall into two groups, those that originate mainly from soil (e.g. Al, K, Na, Th, Ce, La, Sm and Ti), and those (e.g. Ca, Cd, Pb, Cr, Zn, Cu and Au) that primarily originate from other sources, including cement, tyre wear, car emissions and salt. The first group of elements are in lower concentration in London and New York than in the other cities, while the reverse holds for the second group of elements. The concentrations of most elements increase with decrease in the size of the dust particles. The metals, Cd, Pb, Cu, Zn, Mn and Fe were sequentially extracted from the dust into five fractions, exchangeable metal, carbonate bound metal, MnFe oxide bound metal, organic bound metal and the residue.
Land transportation remains one of the main contributors of noise and air pollution in urban areas. This is in addition to traffic congestion and accidents which result in the loss of productive activity. While there is a close relationship between traffic volumes and levels of noise and air pollution, transport authorities often assume that solving traffic congestion would reduce noise and air pollutant levels. Tight control over automobile ownership and use in Singapore has contributed in improving traffic flows, travel speeds and air quality. The adoption of internationally accepted standards on automobile emissions and gasoline have been effective in reducing air pollution from motor vehicles. Demand management measures have largely focused on controlling the source of traffic congestion, i.e. private automobile ownership and its use especially within the Central Business District during the day. This paper reviews and analyzes the effectiveness of two measures which are instrumental in controlling congestion and automobile ownership, i.e. road pricing and the vehicle quota scheme (VQS). While these measures have been successful in achieving desired objectives, it has also led to the spreading of traffic externalities to other roads in the network, loss in consumer welfare and rent seeking by automobile traders.
While emissions control regulation has led to a substantial reduction in exhaust emissions from road traffic, currently non-exhaust emissions from road vehicles are unabated. These include particles from brake wear, tyre wear, road surface abrasion and resuspension in the wake of passing traffic. Quantification of the magnitude of such emissions is problematic both in the laboratory and the field and the latter depends heavily upon a knowledge of the physical and chemical properties of non-exhaust particles. This review looks at each source in turn, reviewing the available information on the source materials and particles derived from them in laboratory studies. In a final section, some of the key publications dealing with measurements in road tunnels and the roadside environment are reviewed. It is concluded that with the exception of brake dust particles which may be identified from their copper (Cu) and antimony (Sb) content, unequivocal identification of particles from other sources is likely to prove extremely difficult, either because of the lack of suitable tracer elements or compounds, or because of the interactions between sources prior to the emission process. Even in the case of brake dust, problems will arise in distinguishing directly emitted particles from those arising from resuspension of deposited brake dust from the road surface, or that derived from entrainment of polluted roadside soils, either directly or as a component of road surface dust.
Mercury (Hg), lead (Pb), cadmium (Cd) and copper (Cu) in hair samples from Singapore island (85 samples) and two islands off Batam, Indonesia (68 samples) were analysed to assess the environmental uptake of elements. Hair samples were washed with 0.1% Triton X-100 solution for 20 min in an ultrasonic bath, rinsed five times with de-ionized water and air dried. Ten to 20 mg of hair samples were digested with 1 ml of ultra-pure concentrated nitric acid in Parr bombs at 120 degrees C for 2 h. Hair digests were analysed by atomic absorption spectrophotometry (AAS). Hg was determined by the cold vapour AAS method and Pb, Cd and Cu by the electro-thermal graphite furnace AAS method. For Singapore hair, the contents of Cd (in microgram/g) averaged 0.17 (range 0.02-1.81); Cu 13.2 (range 3.1-70.1); Hg 5.92 (range 1.14-35.52); and Pb 6.74 (range 0.06-107.8). For the islands off Batam, Cd was 0.32 (range 0.06-1.80); Cu 21.1 (range 3.8-143.6); Hg 5.59 (range 0.78-60.86); and Pb 15.1 (range 0.13-116.6). Statistically significant differences in Cd, Pb and Hg contents were observed between the hair samples from Singapore and those of the islands off Batam in cumulative logit analysis. Hair from Singapore contained more Hg, but less Cd and Pb compared to hair from the islands off Batam. For Pb in hair, significant differences were also observed between the two islands off Batam (island 1, 18.9; and island 2, 10.2). These differences in hair metal contents are due to differences in community lifestyle (dietary, environmental or occupational intake).
This study identified the levels and sources of heavy metal contamination in road dust from busy traffic areas in a typical industrial city in Korea. This study compared the total concentrations, as determined by aqua regia digestions and atomic absorption spectroscopy, of cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn) and nickel (Ni) in the road dust from areas with different characteristics such as traffic rotaries, downtown areas, circulation roads, and asphalt and concrete highways. The contamination levels of the heavy metals in the road dust were evaluated using the contamination factor and the degree of contamination. The contamination levels of the heavy metals in the road dust were highly dependent on traffic volume and atmospheric dispersion from traffic rotaries. Industrial emissions and the frequency of brake use and vehicles coming to a complete stop were additional factors that affected the contamination levels in downtown areas. The concrete highway had higher contamination levels of the heavy metals than the asphalt highway. Vehicle speed was also a strong contributing factor to the degree of contamination of heavy metals in the road dust from the circulation roads and highways.