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Investigation of polycyclic aromatic hydrocarbons in soils from Caserta provincial territory, southern Italy: Spatial distribution, source apportionment, and risk assessment
... As a result, it is critical to monitor PAH levels in soil and keep pollutants discharged within recommended limits. 32 Sierra Leone in West Africa is suffering from numerous environmental problems (soil, water, and air pollution) due to the lack of an adequate environmental quality monitoring system. According to 33 combustion activities, untreated municipal solid waste dumping, automobile emissions, industrial emissions, wood burning, agricultural activities, and other factors all contribute to Sierra Leone's environmental contamination. ...
... † The total PAH mean concentration observed in KT soil (1142 ng g −1 dw) was signicantly higher than those found in urban soils in Turin (857 ng g −1 dw), Italy; 13 rural areas (333 ng g −1 dw), southern Italy; 48 Dajiuhu (42.4 ng g −1 dw), central China; 11 and Caserta provincial territory (84.9 ng g −1 dw), southern Italy. 32 Nonetheless, PAH levels in our research were lower as compared to other world regions, including Shenyang (2370 ng g −1 dw), China; 49 Beijing urban areas (3917 ng g −1 dw), China; 16 Glasgow urban areas (11 930 ng g −1 dw), UK; 13 Delhi rural areas (1910 ng (Table S2 †). In general, these studies collectively reported the proximity of anthropogenic activities such as combustion, industrialization, agriculture, economic growth, land use, and densely populated urban areas to enhance PAH pollution. ...
... Overall, the clay-silt textures made signicant contributions in KB and BG soils, thus suggesting that PAH in KB and BG soils might have quicker release rates and high bioavailability and size based on their hydrophobicity as compared to WL and KT soils with a high proportion of sand. 32,77 Moreover, clay-silt particles in KB and BG may have strong PAH binding capacities as compared to MK and SN, and a much stronger binding capacity of PAH than those in WL and KT due to increasing clay-silt particle surface areas. As mentioned above, soil pH was strongly correlated with PAH contents, compared to some studies that investigated high soil organic matter (SOM) with binding capacity at lower pH. ...
This study investigates the concentration and distribution of polycyclic aromatic hydrocarbons (PAHs) in soils, potential sources, risk assessment, and soil physicochemical properties influencing PAH distribution in developed and remote cities in Sierra Leone. Seventeen topsoil samples (0-20 cm) were collected and analyzed for 16 PAHs. The average concentrations of Σ16PAH in soils in the surveyed areas were 1142 ng g-1 dw, 265 ng g-1 dw, 79.7 ng g-1 dw, 54.3 ng g-1 dw, 54.2 ng g-1 dw, 52.3 ng g-1 dw, and 36.6 ng g-1 dw in Kingtom, Waterloo, Magburaka, Bonganema, Kabala, Sinikoro, and Makeni, respectively. Based on the European soil quality guidelines, Kingtom and Waterloo soils were categorized as heavily and weakly contaminated soil PAHs respectively. The main PAH compounds of this study were 2-ring, 4-ring, and 5-ring PAHs. High molecular weight PAHs (4-6 rings) made up 62.5% of the total PAHs, while low molecular weight PAHs (2-3 rings) was 37.5%. In general, HMWPAHs were predominant in Kingtom, followed by Waterloo. The appointment of PAH sources using different methods revealed mixed sources, but predominantly pyrogenic sources (petroleum, biomass, coal, and fossil fuel contributions). Soil pH has a significant impact on PAH distribution. The toxicity equivalent quantity (TEQBaP) levels in soils pose a potential health risk to residents in developed cities but pose a negligible health risk to residents in remote cities. This study is significant as its findings reveal the status of PAH soil contamination in Sierra Leone. The results have important implications for policymakers and stakeholders to identify high-risk zones and establish proper environmental monitoring programs, pollution control measures, and remediation strategies to prevent future risks.
... Residents are exposed to PAHs carried by ash/dust particles along the three main paths of exposure: ingestion, inhalation and Table 1. Exposure parameters in the probabilistic exposure risk assessment and their variable value range (Justifications for the selection provided in [44] ABS unitless Log-normal LN (0.13, 1.26) [43,45,46] EF day year -1 Log-normal LN (252, 1.01) [41,47] CSF ingestion mg kg -1 day -1 Log-normal LN (7.3, 1.56) [42] CSF inhalation mg kg -1 day -1 Log-normal LN (3.14, 1.8) [47] CSF dermal mg kg -1 day -1 37.47 [48] PEF soil mg 3 kg -1 1.36 Â 10 9 [ 40,43] LN (gm, gsd): Geometric mean and geometric standard deviation. U (min, max): Minimum and maximum data. ...
... Residents are exposed to PAHs carried by ash/dust particles along the three main paths of exposure: ingestion, inhalation and Table 1. Exposure parameters in the probabilistic exposure risk assessment and their variable value range (Justifications for the selection provided in [44] ABS unitless Log-normal LN (0.13, 1.26) [43,45,46] EF day year -1 Log-normal LN (252, 1.01) [41,47] CSF ingestion mg kg -1 day -1 Log-normal LN (7.3, 1.56) [42] CSF inhalation mg kg -1 day -1 Log-normal LN (3.14, 1.8) [47] CSF dermal mg kg -1 day -1 37.47 [48] PEF soil mg 3 kg -1 1.36 Â 10 9 [ 40,43] LN (gm, gsd): Geometric mean and geometric standard deviation. U (min, max): Minimum and maximum data. ...
... The values for relative skin adherence factor for soil used in the current study are the most commonly used values (for both age groups) and have been used previously in Chinese [42,68,40] , Italian [69,43] , Taiwanese [70] and Indian [13,71] studies. These values are adopted worldwide from the recommendation of [45] . ...
Profiling and cancer risk assessment on the polycyclic aromatic hydrocarbons (PAHs) content of coal ashes produced by the major coal combustion plants from the eastern coalfield region in India was conducted. Thirteen PAHs were detected on coal ashes collected from ash deposition sites of major thermal power plants and the profiling of the PAHs was done. Benzo[a]pyrene equivalents (BaP eq) for individual PAHs were calculated and applied to the probabilistic assessment model from US EPA (1989). Monte Carlo simulations were conducted to assess the risk of inhabitants exposed to PAHs through the dust of the coal ash deposition site. In fly ash, the range of total amount of carcinogenic PAHs was from 3.50 to 6.72 mg g À1 and for the bottom ash, the range was 8.49 to 14.91 mg g À1. Bottom ashes were loaded with ample amounts of 5-and 6-ring carcinogenic PAHs, whereas fly ashes were dominated by medium molecular weight PAHs. The simulated mean cancer risks from fly ashes were 2.187 E-06 for children and 3.749 E-06 for adults. For the case of bottom ash, the mean risks were 1.248 E-05 and 2.173 E-05 respectively for children and adults. Among all the three exposure routes, dermal contact was the major and caused 81% of the total cancer risk. The most sensitive parameters were exposure duration and relative skin adherence factor for soil, which contributed the most to total variation. The 90% risks calculated from the bottom ashes (2.617 E-05 for children and 4.803 E-05 for adults) are marginally above the acceptable limit (>1.000
... Polycyclic aromatic hydrocarbons (PAHs) are a group of pollutants with highly stable chemical structures that can be originated by different sources [1][2][3]. Although natural sources such as the petrogenic process can generate PAHs, anthropogenic sources, such as the incomplete combustion of biomass, coal, diesel, and other fossil fuels, the direct release of oil and its products, and their emissions from power generation plants and coke ovens, contribute more to their concentrations in the natural environment [4][5][6]. Once released into the environment, PAHs are transported and distributed within different environmental media, such as soils and sediments, water bodies, and the atmosphere. Surface soils are considered to be large reservoirs and sinks for PAHs, due to the physicochemical properties of soils that enable the adsorption of PAH compounds to soil particles with high organic matter content [3,7,8]. ...
... Various studies, including work done by the International Agency for Research on Cancer (IARC), have shown that PAHs are a group of toxic compounds with ecotoxic, genotoxic, mutagenic, and estrogenic effects [5][6][7]9]. Additionally, their adverse effects intensify with their accumulation and amplification in biological organisms [2,5,7]. ...
... In order to evaluate the cancer risks posed by the PAHs in soils and other environmental media, a health risk assessment model and an incremental lifetime cancer risk (ILCR) assessment model were proposed by the US Environmental Protection Agency (US EPA), two approaches which have been widely used by various authors [8,10,11]. Considering the different carcinogenic potencies of different PAH compounds, the toxic equivalent quantity for Benzo(a)Pyrene (BaP TEQ ) calculated from the PAH concentrations and their toxic equivalent factors (TEFs) were used in the cancer risk assessment [1,6,7]. However, the contributions of different PAH sources to the BaP TEQ concentration and their associated cancer risks were rarely reported in the literature. ...
Beijing and Tianjin are two of the largest cities in northern China with high population densities and highly developed manufacturing industries. In the past decade, some authors have reported their PAH concentrations in surface soils, identified their sources and quantitatively reported their health risks. However, the contributions of different PAH sources to their toxicity have not been reported thus far. In this study, we reviewed the PAH concentrations, contributions of different sources to the toxicity, and cancer risks in soils from different land use types found within Beijing and Tianjin from data gathered by 41 studies. The total PAH concentration varied in the range of 175.7–1989.0 ng g ⁻¹ with a higher median PAH concentration detected in urban soils (789.7 ng g ⁻¹ ), followed by suburban soils (647.3 ng g ⁻¹ ) and rural soils (390.8 ng g ⁻¹ ). Source identification using diagnostic ratios and principal component analysis (PCA) suggested that the PAHs in all three land use types mainly originated from biomass and coal combustion, vehicular emissions, and petrogenic processes with contributions varying from 13% to 62%. Furthermore, results from a positive matrix factorization (PMF) model suggested that vehicular emissions and coal combustion in urban soils, and the vehicular emissions, coal combustion and biomass combustion in suburban and rural soils dominated the total PAH concentrations (>85%). These results were consistent with those of the PCA model. Results of the additional toxicity apportionment performed using the PMF model suggested that vehicular emissions and coal combustion contributed the most to the toxic equivalent quantity for Benzo(a)Pyrene (BaP TEQ ) and, by extension, to the carcinogenic potencies. The incremental lifetime cancer risk (ILCR) values suggested a low risk level for adults exposed to PAHs in the different land use types found within Beijing and Tianjin.
... In addition, it was demonstrated that some territorial units (i.e., Sarno River basin, Naples urban and metropolitan areas) De Vivo et al., 2016;Lima et al., 2017;Minolfi et al., 2018, and references therein) other than the Campania plain are also affected by environmental problems. The results of the "Campania Trasparente" project (De Vivo et al., 2021a;De Vivo et al., 2021b;De Vivo et al., 2022;Qi et al., 2020;Qu et al., 2016;Qu et al., 2018a;Qu et al., 2019b;Qu et al., 2021) from which stem the present study, reinforced, even more, this latter evidence. ...
... The research group in environmental geochemistry at the Department of Earth, Environment and Resources Sciences dealt with two tasks. Specifically, the group completed, on one aspect, the analysis and elaboration of geochemical data relating to the concentration of PTMs and POPs in regional topsoils and subsoils (De Vivo et al., 2021a;De Vivo et al., 2021b;Qi et al., 2020;Qu et al., 2019b), and, on another aspect, the monitoring of air pollutants through the use of passive sampling techniques (Qu et al., 2018a;Qu et al., 2021). Details on methods are given in the following sections. ...
... The Campania region consists of four provinces (Avellino, Benevento, Caserta, Salerno) and one metropolitan city (Naples). Several findings involving air-soil exchange and health risk of POPs have been published on the provincial territories, such as Caserta (Qi et al., 2020), Benevento (Qu et al., 2019a) and NMA (Qu et al., 2019b). Given space limitations, the air-soil exchange process and risk for exposure to POPs is not fully explored here. ...
... However, to date, there are few POP studies that have been conducted with large atmospheric sample sizes, even with the use of PASs. Limiting the sample size restricts spatial data visualization (e.g., concentration and risk level)-a method that has been successfully used in other environmental media, such as soil and sediment studies (Qi et al., 2020;Qu et al., 2018b). The Campania region of southern Italy has long suffered from severe potentially toxic metal (PTM) pollution and is plagued by organic pollutants (Albanese et al., 2010;Cicchella et al., 2016;Senior and Mazza, 2004). ...
... Phe and Flu are the dominant components of ultrafine particles in gasoline exhaust and diesel-fueled vehicles, so their abundance might indicate contributions from vehicle emissions. There is a general consensus among the scientific community that vehicular exhaust was a dominant emission source in Caserta (Qi et al., 2020). A decreasing urban/rural PAH gradient was observed in this study, which is in good agreement with previous results reported from the NMA (Qu et al., 2019b). ...
... The DFs of four dibenzopyrene isomers (i.e., DBaeP, DBahP, DBaiP, and DBalP) were almost zero. Furthermore, the only site with detectable dibenzo(a,e) pyrene overlaps the hotspot area, which was identified by a recent PAH survey of Caserta Territory soil (Qi et al., 2020). ...
Because most relevant studies have used small sample sizes, to date, representative atmospheric monitoring of persistent organic pollutants (POPs) on a regional scale has been very limited, which makes it difficult to precisely identify “hotspots” and possible pollution sources. In this study, an ultrahigh resolution monitoring technique was used to measure the atmospheric spatial variations in POP concentrations on a regional scale, throughout Campania, Italy. The occurrence of specific POPs—including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and phthalate esters (PAEs)—were investigated using polyurethane foam-based passive air samplers (PUF-PAS), which were deployed at 129 sites across the Campania Territory between April and July 2016. The results show that the highest POP levels occurred in the Naples metropolitan area (NMA), although there were other problematic spots throughout the Territory. More specifically, hotspot areas in the NMA that depict serious POP pollution were found in the Bagnoli brownfield site, Sarno River Basin, and parts of the northeastern NMA sector. The atmospheric POP contamination in Campania is jointly controlled by the contributions of local emissions and long-range atmospheric transport. Diffusion model was employed to identify the potential sources of various POPs. The simulation showed that all the POP sources are located in the NMA and are closely related to industrial sites. This study demonstrates the advantage of using large sample sizes to identify POP source locations and achieve geospatial visualization of POP concentration and risk assessment levels.
... Besides, TMLs can cause a possible health risk to humans via external exposure, breathing, and the food web (Guan et al., 2018;Liu et al., 2019). TMLs may harm human health because some (i.e., As, Cd, Hg, and Cr) are carcinogenic and mutagenic (Qi et al., 2020). To lessen the health hazard of TMLs, it is crucial to identify and understand their abundance, distribution, origin, and health issues in the natural ecosystem . ...
... Both models were applied to get more consistent source distribution and identification with various ranking and contribution rates (Khan et al., 2023). Human body variability creates uncertainty in risk assessments (Chen et al., 2016;Qi et al., 2020). Monte Carlo simulation was used to lower the uncertainty of human health risk assessments . ...
Toxic metal(loid)s (TMLs) in agricultural soils cause detrimental effects on ecosystem and human health. Therefore, source-specific health risk apportionment is very crucial for the prevention and control of TMLs in agricultural soils. In this study, 149 surface soil samples were taken from a coal mining region in northwest Bangladesh and analyzed for 12 TMLs (Pb, Cd, Ni, Cr, Mn, Fe, Co, Zn, Cu, As, Se, and Hg). Positive matrix factorization (PMF) and absolute principal component score-multiple linear regression (APCS-MLR) receptor models were employed to quantify the pollution sources of soil TMLs. Both models identified five possible sources of pollution: agrochemical practice, industrial emissions, coal-power-plant, geogenic source, and atmospheric deposition, while the contribution rates of each source were calculated as 28.2%, 17.2%, 19.3%, 19% and 16.3% in APCS-MLR, 22.2%, 13.4%, 24.3%, 15.1% and 25.1% in PMF, respectively. Agrochemical practice was the major source of non-carcinogenic risk (NCR) (adults: 32.37%, children: 31.54%), while atmospheric deposition was the highest source of carcinogenic risk (CR) (adults: 48.83%, children: 50.11%). NCR and CR values for adults were slightly higher than for children. However, the trends in NCR and CR between children and adults were similar. As a result, among the sources of pollution, agrochemical practices and atmospheric deposition have been identified as the primary sources of soil TMLs, so prevention and control strategies should be applied primarily for these pollution sources in order to protect human health.
... Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent and ubiquitous organic pollutants in the environment. The incomplete combustion of organic materials has the potential to produce PAHs (Basant and Balram 2016;Qi et al. 2020). Human activities are known to be important sources of excessive accumulation of PAHs in environment, including industrial and civil coal burning, traffic combustion emissions, biomass combustion, and coking emissions (Jiang et al. 2009;Qu et al. 2020). ...
... The average content of soil Σ16PAHs in the Taiyuan residential areas was 1835 ± 1695 ng·g −1 (geometric mean: 1082 ng·g −1 ) ng·g −1 , which was less than that in parks in Beijing (6653 ng·g −1 ) (Zhang et al. 2016), but it exceeded that of the green spaces in Shenzhen (72 ng·g −1 ) and parks in Hong Kong (811 ng·g −1 ) (Chung et al. 2007). Industrial zones and residential areas were more polluted than those in the Caserta provincial territory in south Italy (29 ng·g −1 ) (Qi et al. 2020), Chennai in India (64 ng·g −1 ) (Rajan et al. 2021), Kathmandu (capital of Nepal) (1172 ng g −1 ) (Pokhrel et al. 2018), and Ahwaz in Iran (1733 ng·g −1 ) (Mohit et al. 2019). The pollution levels of the Σ16PAHs in sewage irrigation area and the cultivation areas were similar, both of which were at a moderate pollution level (600-1000 ng·g −1 ), and the mean value of Σ16PAHs was 648.6 ± 530.5 ng·g −1 (geometric mean: 495.2 ng·g −1 ) and 693.8 ± 412.6 ng·g −1 (geometric mean: 599.4 ng·g −1 ), respectively. ...
Purpose
Taiyuan has been an important energy-producing and heavy chemical industry base in China since the 1950s. The soil PAH content, spatial distribution, sources, and ecological risk in different functional zones in Taiyuan were studied. This is aimed at revealing the pollution characteristics in the long-term accumulation of soil PAHs in different functional areas of provincial industrial capitals represented by Taiyuan. This study also provides a valuable reference for safeguarding human health and pollution treatment.
Materials and methods
Seventy surface soil samples were collected from six districts in Taiyuan. The content of the 21 different PAHs was determined by GC–MS. According to field investigation of the current land use and the geographic environment around the sample sites, the 70 samples were classified into five categories: industrial zone, sewage irrigation area, cultivation area, residential areas, and ecological zone. The spatial agglomeration characteristics of the PAHs were analyzed using Moran’s index. The main emission sources of the PAHs were explored using diagnostic ratios (DRs) and a positive matrix factorization (PMF) model. The impact of the PAHs on the ecological environment was evaluated using risk quotient values (RQs).
Results and discussion
The average content of Σ21PAHs in different functional areas was in the order of industrial zones (2376 ± 1395 ng·g⁻¹) > residential areas (2109 ± 1950 ng·g⁻¹) > cultivation areas (830.3 ± 494.7 ng·g⁻¹) > sewage irrigation area (794.5 ± 634.9 ng·g⁻¹) > ecological zones (392.6 ± 232.1 ng·g⁻¹). The proportion of 3–5-ring PAHs and seven carcinogenic PAHs in Σ21PAHs were approximately 87–90% and 32–37%, respectively. High to high spatial cluster of PAHs was mainly distributed in industrial zones. PMF analysis indicated that the sources of the PAHs in the five functional zones were mainly coal burning and traffic emissions (approximately 47–60%). The ecological risk assessment suggested that nearly 92% of the soil samples had medium–high ecological risk in industrial zones.
Conclusions
The PAH content in 70 soil samples from Taiyuan obeyed log-normal distribution. There was a significant variation in soil PAH content in different functional areas. 3–5-ring PAHs were predominant. The soils of the industrial zones and residential areas were more severely contaminated with PAHs than those of the other soils. There were clear differences in sources and risks of the different functional areas. Therefore, remediation of soil contamination in Taiyuan should be considered.
... Concentrations of PAHs found in soil in other parts of China and other countries are shown in Table S3. The mean P PAHs 16 concentration in the soil in YRD was comparable to concentrations in soil from urban areas in Harbin (China) (Ma et al., 2009) and Caserta (Italy) (Qi et al., 2020). The P PAHs 16 concentrations were higher than in soil from industrial areas in Suzhou (China) Qi et al., 2020) and urban and rural areas in Beijing and Tianjin (China) (Wang et al., 2010). ...
... The mean P PAHs 16 concentration in the soil in YRD was comparable to concentrations in soil from urban areas in Harbin (China) (Ma et al., 2009) and Caserta (Italy) (Qi et al., 2020). The P PAHs 16 concentrations were higher than in soil from industrial areas in Suzhou (China) Qi et al., 2020) and urban and rural areas in Beijing and Tianjin (China) (Wang et al., 2010). The P PAHs 16 concentrations were much lower than in soil from urban and rural areas in Shanghai (China) (Wang et al., 2013), Dalian (China) (Wang et al., 2007), Jiangsu (China) (Cao et al., 2017), and Lisbon (Portugal) (Cachada et al., 2012). ...
The Yangtze River Delta (YRD) is one of the fastest developing areas in eastern China and contains many chemical industry parks. The profiles and sources of polycyclic aromatic hydrocarbons (PAHs) in soil in chemical industry parks and surrounding areas in the YRD were investigated by analyzing soil samples (n=64) were collected in the YRD and Rudong chemical park (RD), a typical chemical park in the Yangtze River Delta. The total concentrations of 19 PAHs in the YRD soil samples were 16.3–4694 ng·g⁻¹ (mean 688 ng·g⁻¹), and the total concentrations of PAHs in RD were 21.6-246 ng·g⁻¹ (mean 75.4 ng·g⁻¹). The PAHs in soil in YRD were dominated by four-ring and five-ring PAHs, and the PAHs in RD were dominated by two-ring and three-ring PAHs. It suggested that PAHs may have been supplied to soil in YRD predominantly through coal combustion and vehicle emissions, PAHs in the soil of RD may be due to the volatilization and leakage of chemical raw material. According to the different distribution characteristics of PAHs, the ratio (1.5) of (2+3) rings/4 rings was proposed to identify the chemical source of PAHs. The PAH isomer ratios and principal component analysis/multiple linear regression (PCA/MLRA) results indicated that PAHs concentrations in soil in the YRD and RD are mainly supplied by industrial and traffic emissions. Incremental lifetime cancer risks (ILCRs) indicated that PAHs in soil pose negligible cancer risks to children and adults, but much stronger risks to children than adults.
... Several researchers have reported the pattern, sources, and health risk evaluation of PAHs in road or street dusts in many cities across America, Asia, and Europe (Deka et al. 2016;Gope et al. 2020Gope et al. , 2018Hoseini et al. 2016;Hussain et al. 2015;Kamal et al. 2015;Ma et al. 2017;Mon et al. 2020;Najmeddin and Keshavarzi 2019;Qi et al. 2020;Soltani et al. 2015;Yu et al. 2014). However, only very few studies have assessed the causes and human health risks of PAHs in dusts of African cities (Bandowe and Nkansah 2016;Hassanien and Abdel-Latif 2008;Iwegbue et al. 2020;Obiri et al. 2013). ...
... Ratios of PAHs in the environment are used to categorize their sources (Ferrara et al. 2020;Gope et al. 2020;Qi et al. 2020;Tobiszewski and Namiesnik 2012). Bivariate plots of PAHs ratio in road dust of Ibadan are shown in Fig. 4. Specific PAH ratio offers valuable and consistent statistics on PAHs sources. ...
Road dust is a principal source and depository of polycyclic aromatic hydrocarbons (PAHs) in many urban areas of the world. Hence, this study probed the spatial and seasonal pattern, sources, and related cancer health risks of PAHs in the road dusts sampled at ten traffic intersection (TIs) of a model African city. Mixed PAHs sources were ascertained using the diagnostic ratios and positive matrix factorization (PMF) model. The results showed fluctuations in mean concentrations from 36.51 to 43.04 µg/g. Three-ring PAHs were the most abundant PAHs with anthracene (Anth) ranging from 6.84 ± 1.99 to 9.26 ± 4.42 µg/g being the predominant pollutant in Ibadan. Benzo(k)Fluoranthene (BkF) which is a pointer of traffic emission was the most dominant among the seven carcinogenic PAHs considered, varying from 2.68 ± 0.43 to 4.59 ± 0.48 µg/g. Seasonal variation results showed that PAH concentrations were 20% higher during dry season than rainy season. The seven sources of PAHs identified by PMF model include the following: diesel vehicle exhausts, gasoline combustion, diesel combustion, coal tar combustion, gasoline vehicle exhausts, coal and wood (biomass) combustion, and emissions from unburnt fossil fuels. Employing the incremental lifetime cancer risk (ILCR) model, the city’s cancer risk of 5.96E-05 for children and 6.60E-05 for adults were more than the satisfactory risk baseline of ILCR ≤ 10⁻⁶ and higher in adults than in Children.
... It is one of the global human activities that is associated with negative impacts on the environment (Potter & Bailey, 2008), especially in densely populated urban areas (Rodrigue et al., 2009). Polycyclic aromatic hydrocarbons (PAHs) are one of the most widespread groups of organic micro-contaminants present in environmental solid matrices of urban areas (Liu et al., 2010a;Vane et al., 2014;Jiang et al., 2016;Ciarkowska et al., 2019;Ehigbor et al., 2020;Gupta & Kumar, 2020;Konstantinova et al., 2020a;Qi et al., 2020;dos Santos et al., 2021). There are many individual compounds from the PAH group (Wenzl et al., 2006), but the most investigated PAHs in environmental compartments are sixteen PAHs included in the US EPA priority pollutant list (Keith, 2015). ...
... Previous studies suggested various conclusions about the influence of soil organic matter on PAH concentrations in urban soils, which are essentially constantly exposed to significant inputs of PAHs from anthropogenic sources. While some authors confirmed a significant positive relationship between PAH concentrations and TOC (Vane et al., 2014;Qi et al., 2020;Yang et al., 2021), others found no correlations (Agarwal, 2009;Liu et al., 2010a). This is explained either by the constant fresh entry of PAHs into the soil causing a sorption disequilibrium between PAHs and TOC or by the more significant influence of black carbons, such as soot and chars, on the sorption of PAHs in urban soils (Agarwal & Bucheli, 2011;Wu et al., 2018). ...
Combustion of fossil fuels is the most important source of polycyclic aromatic hydrocarbons (PAHs) in the environment. Cities are typical of many human activities which are dependent on fossil fuels (road and railway transport, heat generation, waste incineration and industry) on a small area, leading to high concentrations of PAHs in urban air, dust and soil. The aim of this study was to determine the possible influence of urban traffic on the accumulation of sixteen priority PAHs in soils (n = 132 at two soil depths of 0–10 cm and 10–20 cm) taken at intersections (n = 37) with different traffic volumes and road ages. Variable concentrations of the sum of PAHs (∑16PAH) ranging from 188 to 21,950 μg/kg with a mean and median of 3021 μg/kg and 1930 μg/kg were recorded, respectively. Concentrations of PAHs positively correlated with soil organic carbon content (TOC) (rSpearman = 0.518; p < 0.001). Statistically significant positive correlations between ∑16PAH concentrations and traffic volume/road age were found in this study (rSpearman = 0.689/0.619; p < 0.001), while ∑16PAH concentration decreased with increasing distance from the road edge and was statistically lower at a soil depth of 10–20 cm than at 0–10 cm (p < 0.05). Multivariate statistical methods (principal component analysis and cluster analysis) applied to log-ratio transformed data (clr) to decrease the constant sum constraint coupled with positive matrix factorisation (PMF) modelling pointed to the dominance of pyrogenic emission sources, with 62.1% traffic-related (petrol and diesel emissions, liquid fuel and motor oil spills, and tyre wear) according to PMF results.
... In other words, the source contributing the highest PAH concentration might not be the most important source of cancer risk. Many previous studies have determined the risk level from PAH concentrations without providing the major contributor of risk Qi et al., 2020). However, owing to the different toxicities of PAHs, the contributions of the sources to the risks are more important for protecting human health via source-oriented mitigation. ...
... The PMF receptor model released by the US EPA (version 5.0, www. epa.gov) was employed to identify the sources of PAHs and quantify the contributions of various sources based on their fingerprints (Qi et al., 2020;Yu et al., 2019). Compared with other models for source apportionment, such as the Unmix receptor model and principal component analysis with multiple linear regression, the advantages of the PMF model are the utilization of non-negativity constraints and better performance in resolving the factor profiles and contributions by weighing every single value with user-provided uncertainties. ...
As carcinogenic and ubiquitous pollutants, an in-depth understanding of the long-term environmental behaviors of polycyclic aromatic hydrocarbons (PAHs) and their driving forces is crucial for reducing human health risks. Based on long-term monitoring data from 2001 to 2016, this study systematically investigated the temporal and seasonal trends, periodic oscillation, source apportionment, and human health risks of PAHs in eight rivers in the Free State of Saxony, Germany. The results showed that the annual average ∑16PAHs (sum of 16 PAH concentrations) ranged from 28.2 ng·L⁻¹ to 202 ng·L⁻¹. Using the Mann–Kendall test, a trend of decreasing PAH concentrations was determined (slope range: -0.103 to -0.0159). Wavelet analysis indicated that the most significant periodic oscillation of PAHs was 10–30 months, with more pollution in winter. Source apportionment analysis suggested that vehicular emissions and coal combustion contributed the most to PAH concentrations (20.6–40.30% and 21.7–41.4%, respectively) and related health risks (54.1–80.1% and 5.61–37.9%, respectively). Furthermore, the risks (oral lifetime: 4.24 × 10⁻⁷–1.34 × 10⁻⁶; dermal lifetime: 2.86 × 10⁻⁵–9.05 × 10⁻⁵) were determined to be low. The data revealed that the substitution of petroleum and coal with cleaner energy would facilitate the mitigation of PAHs.
... Consequently, soils contaminated by PAHs showed low risks for residential populations, considering that 99 % of the soils presented TLCR values under 10 −6 ( Table 7). In the literature, higher TLCR values have been identified in southern Italy, with mean ILCRs of 4.77 × 10 −6 for adults (Qi et al., 2020), and in China, with a mean TLCR value of 1.86 × 10 −6 in Shanghai (Tong et al., 2018) and an ILCR value of 4.4 × 10 −5 in the Yangtze River Delta (Wang et al., 2017b). However, those studies were conducted mainly in industrial and highly urbanised regions and reflect the risks induced by soils under high anthropogenic pressure and not the background contamination over a large territory. ...
... Many studies have demonstrated that exposure through food ingestion significantly contributes to the total risk, as in the Yangtze River Delta, where TLCRs rose from 4.4 × 10 −5 to 9.17 × 10 −4 (Wang et al., 2017b). Similarly, in southern Italy, the risk induced by food ingestion exceeded the risks of the other pathways by 2 orders of magnitude (Qi et al., 2020). Therefore, the potential risks posed by PAHs in French soils could be underestimated, especially since a significant part of the production of cereals (soft wheat and barley) and some vegetables (potato) are cultivated in northern France. ...
Polycyclic aromatic hydrocarbons (PAHs) are persistent
organic pollutants produced by anthropogenic activities that contaminate all
environmental spheres, including soils. This study focused on PAHs measured
in 2154 soils in France, covering the entire territory based on a regular
sampling grid. The quantified concentrations in the Σ15 PAHs ranged
from 5.1 to 31 200 µg kg−1, with a median value of
32.6 µg kg−1, and PAHs were detected in 70 % of the
soil samples. The map of Σ15 PAH concentrations revealed strong
spatial variations in soil contamination throughout France, with larger
concentrations in soils of industrial regions and near major cities. PAH
molecular diagnostic ratios support the historical origin of PAHs in the
northern part of France being linked to the significant emissions of PAHs in
Europe during the industrial period of 1850–1950, in particular with the
contribution of coal and/or biomass combustion and iron–steel production. A health
risk assessment conducted for the residential population resulted in a
median value of 1.07 × 10−8 in total lifetime cancer risk,
with only 20 sites above the limit of 10−6 and one above the limit of
10−5 adopted by the French government. These results reveal the need to
conduct large-scale studies on soil contamination to determine the fate of
PAHs and evaluate the risks induced by soil pollution at a country-level
scale.
... The ratios of 1-MePhe/Phe and FluA/(FluA þ Pyr) indicated the main sources of combustions included many types (Yunker et al., 2002;Qu et al., 2019;Qi et al., 2020). The results in seawater were consistent to previous studies in the North Pacific and Arctic Ocean (Ding et al., 2007;Ma et al., 2013). ...
... The gaseous concentration distribution of Flu and Phe along the cruise transect (the figure above), and the ratios of Flu to Phe as a function to latitude (the figure below) (The domination of Flu and Phe presented inFig. S3). the main sources of grass, wood or coal combustions, and between 0.4 and 0.5 usually suggests petrogenic combustion(Qu et al., 2019;Qi et al., 2020). ...
The North Pacific-Arctic Oceans are important compartments for semi-volatile organic compounds' (SVOCs) global marine inventory, but whether they act as a "source-sink" remains controversial. To study the air-sea exchange and fate of SVOCs during their poleward long-range transport, low-altitude atmosphere and surface seawater were measured for polycyclic aromatic hydrocarbons (PAHs) by passive sampling from July to September in 2014. Gaseous PAH concentrations (0.67-13 ng m⁻³) were dominated by phenanthrene (Phe) and fluorene (Flu), which displayed an inverse correlation with latitude, as well as a significant linear relationship with partial pressure and inverse temperature. Concentrations of PAHs in seawater (1.8-16 ng L⁻¹) showed regional characteristics, with higher levels near the East Asia and lower values in the Bering Strait. The potential impact from the East Asian monsoon was suggested for gaseous PAHs, which – similar to PAHs in surface seawater - were derived from combustion sources. In addition, the data implied net volatilization of PAHs from seawater into the air along the entire cruise; fluxes displayed a similar pattern to regional and monthly distribution of PAHs in seawater. Our results further emphasized that air-sea exchange is an important process for PAHs in the open marine environments.
... The levels of PAHs in the environment are source governed. Receptor models have been widely applied to determine the sources of organic pollutants in the air (Liu et al., 2019a), soil (Qi et al., 2020), and water (Li et al., 2019). With the development of the economy, the industrial structure, consumption pattern, and energy structure may have changed, suggesting a change in the emission source of PAHs. ...
A systematic assessment of the variations in the ecological risk of PAHs and the key emission sources controlling the variations is of great importance to human health and aquatic organisms. PAH concentrations, composition, source, and ecological risk in soils and water in two different periods (2010-2011 and 2019) of three typical epikarst springs in Southwest China were investigated. Results showed that PAH concentrations in soil and water have an overall downward trend (a reduction of 57 % and 93 %, respectively) in the past 10 years, which is consistent with the downward trend in the relative contribution rate of raw coal production (a 66 % reduction). In terms of composition, the proportion of low-ring PAHs decreased, medium-ring and high-ring PAHs increased in the soil profile. The proportion of low-ring PAHs did not change obviously, the proportion of medium-ring PAHs increased, and the proportion of high-ring PAHs decreased in epikarst springs. The source of PAHs changed remarkably over time, the relative contribution of coal combustion to PAHs decreased from 38 % to 20 %, and the vehicle contribution of PAHs increased from 31 % to 44 % in soils. The relative contribution rate of unburned oil and coke oven and biomass combustion change is less. Furthermore, the ecological risk of PAHs in the soils was reduced from moderate risk 2 to moderate risk 1, the risk in epikarst spring was reduced from high risk to moderate risk 2 after 10 years. This study demonstrates that substituting petroleum and coal with green energies can reduce PAH concentrations and risk.
... The RPF approach is commonly used to evaluate the chemicals with "common mechanism of toxicity" according to the theoretical basis of the chemicals have the same toxic mechanism while in different degree. The RPF is characterized to normalize the potency of each chemical to the index compound for integration of pesticides (Zhang et al. 2018;Qi et al. 2020), which is recommended by the Food Quality Protection Act (FQPA) for cumulative risk assessments (EPA, U, 2011). Moreover, it has been successfully applied to the cumulative risk assessments of organophosphorus and neonicotinoids (Chen et al. 2019;Cui et al. 2021). ...
The pyrethroids (PYRs) were extensively used to increase agriculture outputs. However, the cumulative exposures of PYRs would bring about potential risks through food intake. It is an urgent requirement to explore the cumulative exposures on the fruits and vegetables. In this study, a total of 1720 samples incorporating eight primary fruits and vegetables collected around China were investigated to assess the health risk for adults and children from eight PYRs. The relative potency factor (RPF) method was employed to reveal both chronic and acute cumulative exposure. As a result, the hazard index (HI) were 0.004 ~ 0.200% and 11.85 ~ 99.19% for chronic and acute cumulative dietary exposure, respectively. The national wide investigation indicated the cumulative assessments were not hazardous. Besides, the acute intake of pear, grape, and lettuce should be paid on more attention, particularly. This study provides compelling evidence to develop relative policy and regulation to improve the food quality and safety.
Graphical abstract
... In this paper we used the pollutant concentration data of the topsoil sampled in correspondence to the fish sampling sites. Soil sampling and analytical procedures are detailed in Zuzolo et al. (2020) for PTEs, in Qi et al. (2020) for PAHs, in Qu et al. (2019a) for OCPs, and in Qu et al. (2019b) for the PCBs. ...
In this study, we investigated the presence, abundance, and chemical nature of microplastics (MPs) in the freshwater fish gastrointestinal tract in the South of Italy, and evaluated the possible correlation between MPs and environmental pollutants. Fifty specimens belonging to five species (Scardinius erythrophthalmus, Barbus barbus, Rutilus rubilio, Leuciscus cephalus, Salmo trutta), from twenty sites were collected. MPs chemical feature was identified by means of Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) and Raman microscopy. MPs were represented by 34.86 % fragments, film, and foam (all together MPs) and 65.14 % by fibers (MFs). The mean number of MPs/MFs per fish ranged from 6.25 ± 4.35 in R. rubilio and 2.26 ± 1.94 in B. barbus. The highest number of MPs/MFs per g of GIT was found in R. rubilio (9.07±9.66), and the lowest in S. erythrophthalmus (0.75±0.53). The highest number of MPs/MFs per fish species was found in L. cephalus (16), and the lowest in S. erythrophthalmus (4). Black predominated in every type of plastic debris identified, followed by blue and white, respectively for MFs andMPs. Polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS), and polypropylene (PP), were the main plastic polymers found. At fish sampling sites, comparing concentrations in soils of potentially toxic elements and persistent organic pollutants with the number ofMPs/MFs in fish, a significant correlation was noted with polychlorinated biphenyls (PCBs) and, in particular, with PCB 105, PCB 118, PCB 156, PCB 157, and PCB 167. A strong correlation was also observed with all types of polycyclic aromatic hydrocarbon (PAHs) particularly with benzo(ghi)perylene, dibenz(a,h)anthracene, benzo(b)fluoranthene, benz(a)anthracene, benzo(a)pyrene, and pyrene. The results of this studywould be useful to draft management and action plans, promote intervention plans aiming at removing threats to species and habitats, and address ways of renaturalization.
... Polycyclic aromatic hydrocarbons (PAHs) have a ubiquitous presence and pose potential risk to the environment, thus attracting considerable public attention (Floehr et al., 2013;Qi et al., 2020a). PAHs react with O 3 , NO 2 − , and •OH, NO 3 − to form PAH derivatives, such as nitrated polycyclic aromatic hydrocarbons (NPAHs) and oxygenated polycyclic aromatic hydrocarbons (OPAHs) through a series of chemical reactions (Bandowe and Meusel, 2017;Qiao et al., 2022). ...
Because polycyclic aromatic compounds (PACs) are persistent, universal, and toxic pollutants, understanding the potential source and ecological risk thereof in lakes is critical to the safety of the aquatic environment. Here, a total of 25 sedimentary samples were collected from Lake Taihu, China, in 2018. The total concentrations of 16 parent polycyclic aromatic hydrocarbons (PAHs), 15 nitrated PAHs (NPAHs), nine oxygenated PAHs (OPAHs), and five hydroxy-PAHs (OH-PAHs) ranged from 294 to 1243, 3.0 to 54.5, 188 to 1897, and 8.3 to 51.7 ng/g dw, with the most abundant compounds being fluoranthene, 1,8-dinitropyrene, 6H-Benzo[cd]pyren-6-one, and 2-phenylphenol, respectively. The spatial distribution of PACs in sediments of Lake Taihu showed elevated concentrations from east to west due to economic development and transportation. The positive correlations between most paired PAHs indicate that these compounds likely originated from similar sources. The total organic carbon and organic matter contents affected the distribution characteristics of PACs in sediments. Diagnostic ratios, principal component analysis-multiple linear regression (PCA-MLR), and positive matrix factorization (PMF) were integrated to identify the sources. PACs had various sources including combustion, petroleum leakage, traffic emissions, hydroxyl metabolism, and other oxidation pathways in sediments of Lake Taihu. The PMF (R2 > 0.9824), which showed better optimal performance compared with PCA-MLR (R2 > 0.9564) for PAHs and derivatives, is recommended as the preferred model for quantitative source analysis. Ecological risk assessment showed that the risk quotient values of OPAHs in sediments were much higher than those of other PACs and should be given special attention.
... To assess the possible carcinogenic risk caused by PAHs in the soil to the human body, the risk values of the three exposure pathways (ingestion, dermal contact and inhalation) were calculated according to the incremental lifetime carcinogenic risk (ILCR) model recommended by the EPA (De Miguel et al. 2007;Liang et al. 2019;Peng et al. 2011b;Qi et al. 2020;Zhang et al. 2015). The formula is as follows: ...
This study investigated the concentration, source, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in farmland soil and crops around the Urumqi Industrial Park in Xinjiang, China. The total concentration of 16 different PAHs in the soil (Quantity: 51) and crop (Species: onion, cabbage, coriander, beans, spinach, celery, lettuce, and sunflower) samples ranged between 2.32 and 225.11 ng/g and between 132.44 and 504.03 ng/g respectively, with average values of 39.29 ± 2.39 ng/g for the soil samples and 295.81 ± 105.00 ng/g for the crop samples. The source analysis of PAHs was performed using the positive matrix factorization and ratio method and identified the high-temperature combustion of fossil fuels, the volatilization of petroleum, coke oven emissions, and traffic emissions as main sources of PAHs in soil. The ecological risk posed by the PAHs detected in the soil samples was within a safe range. The incremental lifetime cancer risk (ILCR) value quantifies resulting from human exposure to soil containing PAH is at a safe level except for the potential carcinogenic risk to children due to ingestion exposure (ILCRs > 1.0 × 10–6). The ILCR posed by crops exceed 1.0 × 10–6 and the risk from sunflower crop was the highest. The highest ILCR values for each crop high exposed for the adult female population. These results indicate that the farmland soil and crops near the Urumqi Industrial Park have been contaminated by PAHs and require urgent remediation to minimize adverse effects of exposure to carcinogens.
... For example, the reported concentration ranges of ∑ 16PAHs were 83.3-7220 ng/g in 57 soil samples collected from the main urban area of Shanghai, China , 37.76-7559.21 ng/g in 121 topsoil samples collected from Beijing urban parks, China , 29-1940 ng/g in an industrial area of Uzbekistan (Bandowe et al., 2021), 10.0-4191 ng/g in soils from Caserta provincial territory, southern Italy (Qi et al., 2020), and 232-990 mg/kg in roadside soil of Ibadan metropolis, Nigeria (Ige et al., 2021). According to the environmental standards for soil issued by some countries, such as the Netherlands and Canada, ∑ 16PAHs concentrations at some countries and regions have exceeded. ...
Inoculation with arbuscular mycorrhizal (AM) fungi can accelerate the phytoremediation process by increasing plant biomass and improving soil physicochemical and biological characteristics. However, a quantitative, data-based conclusion is yet to be derived on the roles of AM fungi in remediating soils polluted by polycyclic aromatic hydrocarbons (PAHs), and the impact factors are unclear. To address these issues, we performed a meta-analysis of 45 articles to estimate the effects of AM inoculation on the phytoremediation of soils polluted by PAHs and to examine the influence of experimental conditions on these effects. Our results showed that AM inoculation significantly decreased the residual soil PAHs concentration at all PAHs levels, and the largest effect of AM treatment was 48.5% compared to the non-mycorrhizal treatment. This should be attributed to increased plant growth and PAHs uptake, and soil biological activity in the rhizosphere induced by AM symbionts. Compared to the non-mycorrhizal treatment, the largest AM effects on the total plant biomass, root PAHs concentration, shoot PAHs concentration, soil bacterial biomass, soil catalase activity, and soil polyphenol oxidase activity were 51.7%, 565%, 53.1%, 141%, 100% and 51.9%, respectively. Although these effects on the above mentioned parameters varied with AM fungi (genus, species, and inoculation mode), soil PAHs (source, concentration, and type), plant type (dicots and monocots), and experimental conditions (experimental duration, soil sterilization and additional factors), few negative AM effects were observed. This study confirmed the feasibility of using AM fungi to enhance the phytoremediation of PAHs-contaminated soil.
... The average concentration of Σ and Orlando, USA 28 , respectively. International Agency for Research on Cancer has categorized 7 isomers, which are BaA, Chr, Bbf, Bkf, Bap, Daha and Inp, as mutagenic and carcinogenic pollutants29,30 . Total concentrations of 7 carcinogenic PAHs (Σ 7c PAHs) were between 742.23 and 9526.1 ng g −1 (mean 4615.7 ng g −1 ) which accounted for about 56.96% of Σ 16 PAHs. ...
Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants. With the expansion of the city, the suburban environment is being increasingly polluted by PAHs, which pose a huge potential risk for suburban agriculture. Therefore, we conducted a survey focusing on the pollution level, sources, and risk of PAHs in Changchun suburban vegetable soils, Northeast China. The total concentrations of 16 PAHs (Σ16PAHs) in soils were between 2338.2 and 15,200 ng g−1 (mean 6778.1 ng g−1), which were significantly higher than those in most other cities. High molecular weight PAHs were the major components, which occupied over 85.63% of all PAHs. Seven potential carcinogenic PAHs accounted for 56.96% of the Σ16PAHs. Source apportionment results based on the ratio of PAH isomers and principal components analysis showed that PAHs were primarily derived from pyrolysis sources, such as biomass/coal combustion, traffic emissions, and petroleum. Ecological risk values of PAHs were between effects range-low (ERL) and effects range-median (ERM), which might cause occasionally ecological risks in the suburbs. According to the incremental lifetime cancer risk assessment results, the health risks to the exposed population were in the acceptable level, with dermal contact and ingestion being the predominant exposure pathway.
... Apportionment of soil pollution sources, which clarifies all of the potential sources, requires uniform sampling of the entire area [40][41][42], but in this study, only the sources related to mining and smelting are considered. Therefore, we provide a brief discussion of the other factors, which mainly depend on the characteristics of the major elements and the land-use types of the sampling locations. ...
Soil heavy metal pollution is frequent around areas with a high concentration of heavy industry enterprises. The integration of geostatistical and chemometric methods has been used to identify sources and the spatial patterns of soil heavy metals. Taking a county in southwestern China as an example, two subregions were analyzed. Subregion R1 mainly contained nonferrous mining, and subregion R2 was affected by smelting. Two factors (R1F1 and R1F2) associated with industry in R1 were extracted through positive matrix factorization (PMF) to obtain contributions to the soil As (64.62%), Cd (77.77%), Cu (53.10%), Pb (75.76%), Zn (59.59%), and Sb (32.66%); two factors (R2F1 and R2F2) also related to industry in R2 were extracted to obtain contributions to the As (53.35%), Cd (32.99%), Cu (53.10%), Pb (56.08%), Zn (67.61%), and Sb (42.79%). Combined with PMF results, cokriging (CK) was applied, and the z-score and root-mean square error were reduced by 11.04% on average due to the homology of heavy metals. Furthermore, a prevention distance of approximately 1800 m for the industries of concern was proposed based on locally weighted regression (LWR). It is concluded that it is necessary to define subregions for apportionment in area with different industries, and CK and LWR analyses could be used to analyze prevention distance.
... Two recent reviews show PAH concentrations in soils and sediments of different geographical regions of the world [4,5]. In particular, because PAHs in urban soils are a risk to the residents' health, the distribution and the concentration of PAHs on urban sites were studied by several authors [6][7][8][9][10][11][12][13]. ...
Polycyclic aromatic hydrocarbons (PAHs) represent a threat to human health and the environment. This review analyzes recent publications about the use of persulfate (PS) for the treatment of PAH-contaminated soils. The reviewed publications reaffirmed the versatility of this oxidant and the convenience of its use. Pollutants and PS concentrations, PS-activation methods, and combination with bioremediation in PS applications were considered. Several studies detected the formation of SO4.- and HO. radicals, with relative amounts, depending on the experimental conditions. The main parameter considered to evaluate the evolution of the treatments was the concentrations of each PAH or the global value. The optimization of the methods was focused on the application and activation of PS. Recommendations for future investigations are included.
... Classification of PAHs sources in the environment are achieved using their indicative (diagnostic) ratios (Ferrara et al., 2020;Gope et al., 2020;Qi et al., 2020;Tobiszewski & Namiesnik, 2012). Plots of PAHs ratio proffer valuable and reliable data on PAHs sources in indoor dusts of Ilorin (Fig. 3). ...
Polycyclic aromatic hydrocarbons (PAHs) have attracted significant attention in recent times on account of their reasonably high environmental burden and extreme toxicity. Samples of indoor dusts were obtained daily over a period of 2 weeks from 10 residences located within low, medium, and high density residential areas of Ilorin City. The concentration levels, potential sources, and cancer health risks of sixteen polycyclic aromatic hydrocarbons (PAHs) were investigated using gas chromatography/mass spectrometry. PAHs total concentrations varied from 3.95 ± 0.19 to 8.70 ± 0.43 μg/g with arithmetic mean of 6.09 ± 0.46 μg/g. Fluoranthene was the most dominant PAHs congener. High molecular weight (HMW) PAHs (4–6 rings) were the most prevalent PAHs and were responsible for 79.29% of total PAHs in sampled residences. Chrysene (Chry) was the most abundant compound among the 7 carcinogenic PAHs (CPAHs). Moreover, diagnostic ratios and positive matrix factorization (PMF) employed to apportion PAHs suggested that indoor dusts originated from indoor activities and infiltrating outdoor air pollutants. Diagnostic ratios revealed that PAHs are from mixed sources which include coal/wood combustion, non-traffic and traffic emissions, petroleum, petrogenic (gasoline), and petroleum combustion. Similarly, positive matrix factorization (PMF) model suggested five sources (factors) were responsible for PAHs in indoor dusts comprised of petroleum combustion and traffic emissions (60.05%), wood and biomass combustion emissions (20.84%), smoke from cooking, incense burning and tobacco (4.17%), gasoline combustion from non-traffic sources (13.89%), and emissions from coal burning and electronic devices (1.05%). The incremental lifetime carcinogenic risks (ILCR) of PAHs in adults and children estimated by applying benzo(a)pyrene (BaP) equivalent were within the satisfactory risk limits in Ilorin. Indoor PAHs emissions in Ilorin residences could be monitored and controlled by using data provided in this study.
... Release of organic chemicals into the agroecosystem occurs intentionally through agrichemical application and unintentionally through atmospheric deposition, contaminated soil amendments (such as manure or biosolids) or the use of contaminated irrigation water (Jiang et al., 2009;Li et al., 2011;Qi et al., 2020;Yurdakul et al., 2019). Plants can act as vectors for transferring chemicals from the environment to the food chain. ...
Accurate prediction of uptake and accumulation of organic contaminants by crops from soils is essential to assessing human exposure via the food chain. However, traditional empirical or mechanistic models frequently show variable performance due to complex interactions among contaminants, soils, and plants. Thus, in this study different machine learning algorithms were compared and applied to predict root concentration factors (RCFs) based on a dataset comprising 57 chemicals and 11 crops, followed by comparison with a traditional linear regression model as the benchmark. The RCF patterns and predictions were investigated by unsupervised t-distributed stochastic neighbor embedding and four supervised machine learning models including Random Forest, Gradient Boosting Regression Tree, Fully Connected Neural Network, and Supporting Vector Regression based on 15 property descriptors. The Fully Connected Neural Network demonstrated superior prediction performance for RCFs (R² = 0.79, mean absolute error [MAE] = 0.22) over other machine learning models (R² = 0.68–0.76, MAE = 0.23–0.26). All four machine learning models performed better than the traditional linear regression model (R² = 0.62, MAE = 0.29). Four key property descriptors were identified in predicting RCFs. Specifically, increasing root lipid content and decreasing soil organic matter content increased RCFs, while increasing excess molar refractivity and molecular volume of contaminants decreased RCFs. These results show that machine learning models can improve prediction accuracy by learning nonlinear relationships between RCFs and properties of contaminants, soils, and plants.
... In our study, the absence of either intensive industrial activities or extremely high traffic densities results in low soil PAH contents. The PAH levels measured in Hradec Králové are comparable (or even lower) to those found in other urban areas in Europe, such as Caserta provincial territory, southern Italy (median value 0.029 mg/kg), differently urbanized soils in Lublin (Poland) (from 0.40 to 2.42 mg/kg) and Bratislava, Slovakia (2.06 mg/kg) [41][42][43]. Our results are therefore in agreement with the findings of other studies in cities unaffected by intensive industry and/or traffic densities. ...
... Through several processes, these pollutants found their way to water systems including urban, industrial, and agricultural runoff as well as atmospheric deposition (Hosono et al., 2011;Yılmaz et al., 2016;Zheng, 2008). Primarily, PAHs are originated from incomplete combustion of organic materials (coal combustion, vehicle emissions, domestic heating, biomass burning, industrial activities, oil spillage, etc.), while OCPs have been used widely as pesticides for agriculture, as insecticide, rodenticides, and antifouling agent in history (Oliveira et al., 2016;Qi et al., 2020;Thiombane et al., 2018;Xing et al., 2016;Yılmaz et al., 2016). After the prohibition in the 1980s, OCPs can still be found in different matrices of the environment because of their low degradation/ long half-life (Li et al., , 2018Xing et al., 2020;Zhao et al., 2017a). ...
To elucidate the concentrations, spatial distribution, sources, and risk of sixteen polycyclic aromatic hydrocarbons (PAHs) and 24 organochlorine pesticides (OCPs), thirteen sites were chosen for collecting water, sediment, and soil samples from Daye lake in April 2019. All pollutants were frequently observed in three media of Daye lake. Higher concentrations of OCPs were determined in the soil whereas PAHs were dominant among sediment samples. However, the water of Daye lake is polluted with both of the pollutants. In water, ΣDRINs, ΣDDTs, ΣHCHs and LMW PAHs accounted for 22.1%, 19.6%, 17.9% and 85.5%, respectively. Among sediments, OCPs and PAHs were ranged from 1.53–51.38 ng·g⁻¹ and 14.38–4659.66 ng g⁻¹. While soil accounted for a larger percentage of hepatchlor epoxide i.e. 96.5% and HMW hydrocarbons i.e. 82.7%. Furthermore, low α-to γ-HCH ratio suggested fresh input of HCH and a higher ratio of (DDE + DDD)/DDT determined the historical use of DDT. Additionally, diagnostic molecular ratio along with principal component analysis evaluated that PAHs mainly came from fossil fuel, biomass, and coal combustion. Moreover, ecological risk assessment of Daye lake indicated that the carcinogenic PAHs in water and soil can pose 10% risk to the environment also OCPs in sediments has a visible effect on ecology. According to ILCRs evaluation, OCPs have negligible to low cancer risk among all sites for water, soil, and sediments while PAHs value fluctuated in the midst of 10⁻⁶ to 10⁻² which shows the potential risk of cancer on children as well as adults. Therefore, measures should be taken to control them in time.
... Polycyclic aromatic hydrocarbons (PAHs) have attracted widespread public attention in recent years, on account of their ubiquity in contaminated urban environment (Wang et al., 2017a(Wang et al., , 2020a(Wang et al., , 2020b. Owing to their mutagenicity, carcinogenicity, and strong ecotoxicity to humans or animals, 16 individual PAHs ( ∑ 16 PAHs) have been confirmed as priority control contaminants by the United States Environmental Protection Agency (USEPA, 2015), and the International Agency for Research on Cancer has also categorized 7 isomers ( ∑ 7c PAHs) as mutagenic and carcinogenic pollutants (Idowu et al., 2019;Qi et al., 2020). The sources of PAHs are diverse, and our previous studies have found that vehicle emissions and incomplete combustion of fossil fuels are the primary sources of PAHs in urban environments (Wang et al., 2015(Wang et al., , 2017c. ...
Polycyclic aromatic hydrocarbons (PAHs) are one of the important environmental pollutants that are mainly originated from industrial activities, vehicle emissions, biomass combustion, etc. Nowadays, the surrounding environment of the abandoned industrial area may still have potential health effects on the population, but current researches have paid less attention to this issue. Therefore, we report a comparative investigation focusing on the concentration, distribution, source identification, and risk assessment of PAHs in soils from surrounding areas of an abandoned industrial district and an ecological village in Zhejiang Province, China. Our findings are as follows: the levels of ∑16PAHs ranged from 150.2 to 83096 ng·g⁻¹ with an average concentration of 7680.4 ng·g⁻¹ in industrial area, whereas 49.4 to 778.2 ng·g⁻¹ with an average concentration of 213.5 ng·g⁻¹ in rural area. Although high molecular weight PAHs were both dominant contaminants in study areas, the composition profiles of 16 priority PAHs in soils from the two sampling sites had large differences. Source identification analysis verified that fossil fuel burning and vehicle emissions were the main sources of PAHs in industrial area, while the primary sources were biomass burning and vehicle emission in rural area. The incremental lifetime cancer risk results demonstrated that dermal contact was the most influential factor for all groups, and adults might face higher potential health risk than children in both industrial and rural areas. Moreover, the overall ecological risk of soil PAH pollution was low in rural area, but some individual samples were still high in the abandoned industrial area. Our research is of great significance for the management of the surrounding environment of abandoned industrial areas.
... However, the presence of POPs in various environmental media may diversify the risk by different degrees, and thus even a low inhalation risk should not be ignored. For instance, other related investigations (Qu et al. 2019;Qi et al. 2020) showed that food ingestion was the dominant pathway of OCPs and PAHs exposure, contributing to over 99.9% of CR (Apart from atmospheric inhalation, soil ingestion, dermal contact and inhalation of fugitive dust were the other exposure pathways). ...
From October 2012 to September 2013, air samples of hexachlorocyclohexanes (HCHs) were collected by polyurethane foam passive air samplers (PUF-PAS) from Caiban Village (CbV), Baihua Village (BhV), Bumeishan Village (BmsV) and Qitang Village (QtV), located in the rural region of Zhangzhou, Southeast China. The test results showed that four HCH isomers (α-, β-, γ-, δ-HCH) were ubiquitous with ∑HCHs concentrations ranging from 4.80 to 41.9 pg/m3 and a mean value of 17.7 pg/m3. A seasonal variation was established in the air HCH levels. The highest ∑HCHs concentration was observed in the autumn whereas the lowest was detected in the spring. The ratio α/γ-HCH, which was used to identify the contamination source, revealed that air HCHs originated mainly from historical technical HCH residues and lindane usage. The health risk of inhalation exposure to atmospheric HCHs, assessed by the inhalation dosimetry methodology, was low and considered negligible for the local residents.
Changchun, China is located in one of the world's three golden corn belts. As a key commodity grain base in China, Changchun plays a vital role in providing food security in the northeast. A total of 16 polycyclic aromatic hydrocarbons (PAHs) was analyzed to determine the influence of anthropogenic activities on the environmental quality of agricultural soils under straw burning conditions. The polycyclic aromatic hydrocarbons soil contamination severity was evaluated using the Maliszewska-Kordybach method. The results indicated that the agricultural soils of Changchun are substantial contaminated with PAHs. Petroleum, biomass, and coal combustion are the primary sources of PAH and have been determined using principal component analysis (PCA) and the isomeric ratio approach. The degree of hazard to human health was assessed using toxicity equivalence and increased lifetime cancer risk (ILCR) factors, except in localized areas during adulthood, the general risk was found to be modest. This study provides important information on PAH exposure in agricultural soils in northeast China, and the findings aid in the exploitation of straw and the mitigation of soil environmental concerns, allowing northeast China to achieve green agricultural development.
Extreme environmental disturbances induced by organic contaminated sites impose serious impacts on soil microbiomes. However, our understanding of the responses of the core microbiota and its ecological roles in organic contaminated sites is limited. In this study, we took a typical organic contaminated site as an example and investigated the composition and structure, assembly mechanisms of core taxa and their roles in key ecological functions across soil profiles. Results presented that core microbiota with a considerably lower number of species (7.93%) than occasional taxa presented comparatively high relative abundances (38.04%) yet, which was mainly comprised of phyla Proteobacteria (49.21%), Actinobacteria (12.36%), Chloroflexi (10.63%), and Firmicutes (8.21%). Furthermore, core microbiota was more influenced by geographical differentiation than environmental filtering, which possessed broader niche widths and stronger phylogenetic signals for ecological preferences than occasional taxa. Null modelling suggested that stochastic processes dominated the assembly of the core taxa and maintained a stable proportion along soil depths. Core microbiota had a greater impact on microbial community stability and possessed higher functional redundancy than occasional taxa. Additionally, the structural equation model illustrated that core taxa played pivotal roles in degrading organic contaminants and maintaining key biogeochemical cycles potentially. Overall, this study deepens our knowledge of the ecology of core microbiota under complicated environmental conditions in organic contaminated sites, and provides a fundamental basis for preserving and potentially utilizing core microbiota to maintain soil health.
Nitrated polycyclic aromatic hydrocarbons (NPAHs) have become a concerning topic because of their widespread occurrence and carcinogenicity. However, studies on NPAHs in soils, especially in agricultural soils, are still limited. In this study, a systematic monitoring campaign of 15 NPAHs and 16 polycyclic aromatic hydrocarbons (PAHs) was performed in agricultural soils from the Taige Canal basin in 2018, which is a typical agricultural activity area of the Yangtze River Delta. The total concentration of NPAHs and PAHs ranged from 14.4 to 85.5 ng g-1 and 118-1108 ng g-1, respectively. Among the target analytes, 1,8-dinitropyrene and fluoranthene were the most predominant congeners accounting for 35.0% of ∑15NPAHs and 17.2% of ∑16PAHs, respectively. Four-ring NPAHs and PAHs were predominant, followed by three-ring NPAHs and PAHs. NPAHs and PAHs had a similar spatial distribution pattern with high concentrations in the northeastern Taige Canal basin. The soil mass inventory of ∑16PAHs and ∑15NPAHs was evaluated to be 31.7 and 2.55 metric tons, respectively. Total organic carbon had a significant impact on the distribution of PAHs in soils. The correlation between PAH congeners in agricultural soils was higher than that between NPAH congeners. Based on diagnostic ratios and principal component analysis-multiple linear regression model, vehicle exhaust emission, coal combustion, and biomass combustion were the predominant sources of these NPAHs and PAHs. According to the lifetime incremental carcinogenic risk model, the health risk posed by NPAHs and PAHs in agricultural soils of the Taige Canal basin was virtually negligible. The total health risk in soils of the Taige Canal basin to adults was slightly higher than that to children.
Petroleum contamination surrounding oilfields has attracted more concerns. However, the levels, distribution and source of petroleum of Changqing Oilfield soil still remain lots of knowns, which is important for local environmental protection. Given soil contamination issues in Changqiong Oilfield were investigated. The maximum concentrations of total petroleum hydrocarbons (TPHs), N-alkanes (TNAs) and polycyclic aromatic hydrocarbons (PAHs) were determined to be 1960.29, 96.13 and 0.82 mg/kg, respectively. TPHs were higher in the north than the south of the study area. TPHs decreased in the horizontal and vertical distribution as soil depth and distance from oil wells increased. Source analysis showed that TNAs mainly originated from petroleum, PAHs were controlled by petroleum spills, combustion and traffic. Correlation analysis implied that TPHs residues had an effect on soil environmental quality. This study have important implications for understanding the environmental behavior of petroleum and can provide support for petroleum remediation and risk control.
Substituted polycyclic aromatic hydrocarbons (SPAHs) have shown higher health and ecological risks than the corresponding parent PAHs (PPAHs) from laboratory studies, their variations in freshwater system, especially in surface sediment and pore water, remain inadequate understanding. In this study, we revealed the coexistence, ecological risk, and multiple factors affecting variations and sources of PPAHs and SPAHs (nitrated PAHs (NPAHs), oxygenated PAHs (OPAHs)) in the surface sediment-pore water system from a typical urban river in Northern China. The concentration ranges of Σ26PPAHs, Σ10NPAHs, and Σ4OPAHs in the surface sediments were 153.0–5367.4, not detected (N.D.)–105.4, and 42.2–1177.0 ng·g⁻¹ dry weight, and fell within 0.6–38.8, N.D.–297.9, and N.D.–212.6 ng·mL⁻¹ in the pore waters. The t-distributed stochastic neighbor embedding (SNE) coupled with the partitioning around medoids (PAM) elucidated spatiotemporal the variations in PAHs, emphasizing the impacts of industrial activities and sewage discharges. Besides the geochemical and hydrochemical conditions, SPAHs were affected by the potential secondary formation, especially during the wet season. The method comparisons indicated the advantages of principal component analysis-multivariate linear regression (PCA-MLR) and n-alkanes model on source identification. PAHs mainly originated from fossil fuel combustion and vehicular exhaust. The top risk quotient (RQ) values for PAHs occurred in the urban and industrial sections. A majority of the surface sediment samples emerged with low to moderate exposure risks, while all the pore water samples showed high exposure risks. The RQs of OPAHs were significantly higher (p < 0.01) than those of PPAHs. The results suggested the secondary formation of SPAHs as an important role in ecological risks of PAHs in the urban river system.
The challenge in optimizing the method of constructing species sensitivity distribution (SSD) remains. In this study, a model-averaging SSD was created to evaluate the ecological risk of Phenanthrene (PHE) in urban watershed based on reproductive fitness. Specifically, concentrations of PHE were measured in surface water samples collected from various watersheds of Wuhan, including five lake watersheds and the Wuhan reach of the Yangtze River and Han River. The reproductive endpoint of aquatic species was calculated to be most sensitive to PHE exposure, with the value of predict no-effect concentration (PNEC) at 0.19 μg/L. The results of probabilistic assessment methods, including joint probability curve (JPC), overall risk probability (ORP), and distribution-based quotient (DBQ), indicated that the ecological risks of PHE in large lakes have dropped significantly with distance from the downtown area of Wuhan, and the long-term effects of industrial activities may increase the risks in the lake watersheds. Basically, the ecological risks in Yangtze River are negligible; however, there is a relatively high risk of PHE in the Han River and some lake watersheds. The cos θ similarity analysis indicated the Yangtze River is strongly connected to the low-risk lake watersheds, and that in part reflects the risk in the Yangtze River being controlled by its surrounding these lake watersheds.
Ambient polycyclic aromatic hydrocarbons (PAHs) emissions are a major environmental problem in urban areas. We aimed to assess the concentration of PAHs-bound to particulate matter (PM), source apportionment and carcinogenic risk due to inhalation exposure to PAHs. We selected 30 sampling locations in Sabzevar, Iran (2021). PM bounds-PAHs samples were collected using a PM passive sampler. Monte Carlo simulation technique with sensitivity analysis was used to assess the carcinogenic risk of inhalation exposure to PAHs. The Positive Matrix Factorization (PMF) model was used for source apportionment of ambient PAHs. The median (iterquartile range (IQR)) of total PAHs was 1056.2 (848.5) ppb. The median (IQR) ratio of total LMW/HMW PAHs was 1.9 (1.4), indicating petrogenic sources of PAHs. The 95th percentile of lifetime cancer risk (LTCR) for children, adolescents, and adults in both genders was higher than the threshold level recommended by USEPA (i.e., 1 × 10⁻⁶). The PMF model indicated five possible PAH sources, including combustion of biomass, natural gas, combustion petroleum-based fuels, traffic sources of mixed gasoline and diesel combustion, and industrial activities. The spatial autocorrelation models indicated a clustered distribution pattern for all PAHs congeners except Anthracene. Our results suggested that point sources of ambient PAHs should be paid more attention to in urban areas. Moreover, inhalation exposure to ambient PAHs had a potential carcinogenic risk for the inhabitant of Sabzevar.
The distributions and correlations among polycyclic aromatic hydrocarbons (PAHs) in soils and plants were analyzed. In this study, 9 soil samples and 44 plant samples were collected near major lakes (Hongze Lake, Luoma Lake, Chaohu, Changhu, Danjiangkou Reservoir, Wuhan East Lake, Longgan Lake, Qiandao Lake and Liangzi Lake) in eastern China. The following results were obtained: The total contents of PAHs in soil varied from 99.17 to 552.10 ng/g with an average of 190.35 ng/g, and the total contents of PAHs in plants varied from 122.93 to 743.44 ng/g, with an average of 274.66 ng/g. The PAHs in soil were dominated by medium- and low-molecular-weight PAHs, while the PAHs in plants were dominated by low-molecular-weight PAHs. The proportion of high-molecular-weight PAHs was the lowest in both soil and plants. Diagnostic ratios and principal component analysis (PCA) identified combustion as the main source of PAHs in soil and plants. The plant PAH monomer content was negatively correlated with Koa. Acenaphthylene, anthracene, benzo[k]fluoranthene, benzo[b]fluoranthene and dibenzo[a,h]anthracene were significantly correlated in plants and soil. In addition, no significant correlation between the total contents of the 16 PAHs and the content of high-, medium-, and low-molecular-weight PAHs in plants and soil was found. Bidens pilosa L. and Gaillardia pulchella Foug in the Compositae family and cron in the Poaceae family showed relatively stronger accumulation of PAHs, indicating their potential for phytoremediation.
Soil is a key component of terrestrial ecosystems, as it provides nutrients and energy for all terrestrial organisms and is the site of various physical, chemical, and biological processes. Soil organic matter is particularly important for the role that it plays in element cycling, as well as the adsorption and degradation of soil pollutants. Nitrogen (N) fertilizer is an important nutrient element in the soil microenvironment. Applications of N fertilizer can improve soil quality, but the long-term excessive application of N fertilizer can lead to the deterioration of the soil environment, alter the properties of organic matter, and affect the adsorption and accumulation of soil pollutants. In recent years, several pollutants, especially polycyclic aromatic hydrocarbons (PAHs), have accumulated in farmland soil due to long-term sewage irrigation. However, few studies have examined the response of soil PAHs accumulation to long-term N application, as well as the relationship between this response and changes in soil microenvironmental indicators caused by N application. Here, we conducted field experiments to study changes in soil pH, total organic carbon, and dissolved organic matter (DOM) under long-term N application, as well as their effects on PAHs accumulation. The application of N fertilizer resulted in the aromatization and humification of soil DOM, enhanced the accumulation response ratio (−0.05–0.32) and the amount of PAHs accumulated in soil (more than 30%), and exacerbated the environmental risks of PAHs. Our findings provide new insights that could aid the management and control of PAHs pollution of soil in sewage-irrigated areas.
Over the last two decades, the Campania region in Italy has been the focus of public debate and concern about environmental issues. Using data from soil, water, air, vegetables, animal products, and human blood, a multimedia monitoring study was performed to measure the contribution of persistent organic pollutants (POPs) to pollution in the region. We report results for a range of POPs in the air, including organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and phthalate esters (PAEs). Most of these chemicals are ubiquitous, with higher concentrations occurring in the urban and metropolitan territory of Naples. The residues of OCPs are attributed to their historical use; however, evidence of recent usage of technical Endosulfan exists in some areas. Although petrogenic sources are widespread, the pyrogenic source has dominated the release of PAHs. The Naples metropolitan area (NMA) serves as a regional emitter of POPs, and the long-term soil re-emission of some POPs does still exist. There are certain risks related to soil-borne PAHs, mainly in the urban (e.g., the Bagnoli brownfield site) and NMA, and more subordinately, in other provincial areas.
Soil polycyclic aromatic hydrocarbons (PAHs) generated from industrial processes are highly spatially heterologous, with limited quantitative studies on their main influencing factors. The present study evaluated the soil PAHs in three types of industrial parks (a petrochemical industrial park, a brominated flame retardant manufacturing park, and an e-waste dismantling park) and their surroundings. The total concentrations of 16 PAHs in the parks were 340–2.43 × 10³, 26.2–2.63 × 10³, and 394–2.01 × 10⁴ ng/g, which were significantly higher than those in the surrounding areas by 1–2 orders of magnitude, respectively. The highest soil PAH contamination was observed in the e-waste dismantling park. Nap can be considered as characteristic pollutant in the petrochemical industrial park, while Phe in the flame retardant manufacturing park and e-waste dismantling park. Low molecular weight PAHs (2–3 rings) predominated in the petrochemical industrial park (73.0%) and the surrounding area of brominated flame retardant manufacturing park (80.3%). However, high molecular weight PAHs (4–6 rings) were enriched in the other sampling sites, indicating distinct sources and determinants of soil PAHs. Source apportionment results suggested that PAHs in the parks were mainly derived from the leakage of petroleum products in the petroleum manufacturing process and pyrolysis or combustion of fossil fuels. Contrarily, the PAHs in the surrounding areas could have been derived from the historical coal combustion and traffic emissions. Source emissions, wind direction, and local topography influenced the PAH spatial distributions.
The Wang Lake Wetland is a highly valued area that is protected due to its high biodiversity. The wetland has a complicated hydrological regime and is subject to frequent human disturbance. We hypothesize that fluctuating hydrology and human activities have varied contributions to the temporal and spatial variations of polycyclic aromatic hydrocarbons (PAHs) in the wetland. Soil (SS), sediment (SD), and water, to acquire dissolved phase (DP) and suspended particulate matter (SPM), samples were collected from eight locations during low- and high-flow periods to elucidate multimedia phase distribution and transport of PAHs. Following the onset of the rainy season, the concentration of SPM-associated PAHs increased significantly, while the DP PAHs remained stable. Individual PAH ratios showed that, although pyrogenic sources are common, petrogenic derived compounds are the main source of PAHs in the Wang Lake Wetland. During the high-flow period, the empirical values for logarithms of the organic carbon-normalized partition coefficients (log KOC) of individual PAH-congeners were lower than the corresponding field-observed log KOC values from the SPM-DP and SD-DP systems, reflecting the complexity in evaluating multi-phase PAH partitioning. During the high-flow period, temperature-driven changes may have changed the sediment from a sink to a source for some high molecular weight PAHs. It was determined that human activities governed the PAH loading in the low-flow period, whereas during high-flow conditions, increased rainfall, higher temperatures, and fishery activity are the main factors controlling PAH input to the Wang Lake Wetland.
This study investigated the concentration, source, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in farmland soil and crops around the Urumqi Industrial Park in Xinjiang, China. The total concentration of 16 different PAHs in the soil and crop samples ranged between 2.32 and 225.11 ng/g and between 132.44 and 504.03 ng/g respectively, with average values of 39.29 ± 2.39 ng/g for the soil samples and 295.81 ± 105.00 ng/g for the crop samples. The source analysis of PAHs was performed using the positive matrix factorization and ratio method and identified the high-temperature combustion of fossil fuels, the volatilization of petroleum, coke oven emissions, and traffic emissions as main sources of PAHs in soil. The ecological risk posed by the PAHs detected in the soil samples was within a safe range. The incremental lifetime cancer risk (ILCR) value quantifies resulting from human exposure to soil containing PAH is at a safe level except for the potential carcinogenic risk to children due to ingestion exposure (ILCRs > 1.0×10 ⁻⁶ ). The ILCR posed by crops exceed 1.0×10 ⁻⁶ and the risk from sunflower crop was the highest. The highest ILCR values for each crop was observed for the adult female population. These results indicate that the farmland soil and crops near the Urumqi Industrial Park have been contaminated by PAHs and require urgent remediation to minimize adverse effects of exposure to carcinogens.
Water samples at 13 sites were analyzed to evaluate heavy metals (cobalt, lead, manganese, copper) and benzo(a)pyrene using 2 methods of analysis (high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) kits). The Lesser Zap River is the main tributary of the Tigris and is used as a main source of drinking water in Kirkuk city through the General Kirkuk project. Risk evaluation for benzo(a)pyrene and lead in water samples was accomplished by Monte Carlo simulation. The highest concentrations of B(a)P were recorded at sites S7 and S5, with levels of 0.192 and 0.122 µg L−1 detected by HPLC and ELISA, respectively. The WHO guidelines for benzo[a]pyrene in drinking water recommend 0.7 µg L −1, and none of the samples surpassed this level; moreover, B(a)P levels exceeded EPA standards in 2014 (0.01 µg L−1), particularly when the liquid–liquid extraction method with HPLC was used. Carcinogenic risks for human adults and children exist and are highest during the rainy season as compared with the carcinogenic risk during the dry season and risks for children exceed those of adults. This indicates that the 2nd round of sampling (winter season) harbors more carcinogenic risk than the 1st round of sampling (dry season).
Nitrogen (N) is one of the most important nutrients required by soil and crops. N addition improves soil quality and fertility. However, long-term N addition changes the soil environment, which may affect the adsorption and accumulation of organic pollutants in soil. The adsorption of pollutants by the light fractions (LF) and heavy fractions (HF) of soil, and their resulting risks, might differ. In addition, several organic pollutants, especially PAHs, accumulate in farmland soil under long-term sewage irrigation. However, few studies have examined the response of PAHs to N addition in soil in sewage-irrigated areas, including whether there is a difference in the response of the LF and HF of soil. Here, a long-term experiment was carried out in farmland soils in typical sewage-irrigated areas to reveal the adsorption and accumulation of PAHs in bulk soil, LF, and HF, and the human health and ecological environment risks posed by PAHs under different levels of N addition. Under long-term N addition, the concentration of PAHs in soil increased and fluctuated from 7598 μg kg⁻¹ to 10,414 μg kg⁻¹. Significant differences in the PAHs concentration in the LF (5048 μg kg⁻¹ to 1889 μg kg⁻¹) and HF (2536 μg kg⁻¹ to 8521 μg kg⁻¹) and the human health and ecological risks of soil with N addition in typical sewage-irrigated areas were observed. The HF of soil was characterized by low carcinogenic and ecological risks. The results of our research provide insight into possible management actions that could be taken to enhance the environmental protection and safety of agricultural production activities, such as sustainability fertilization.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous priority pollutants that cause great damage to the natural environment and health. Average genome size in a community is critical for shedding light on microbiome’s functional response to pollution stress within an environment. Here, microcosms under different concentrations were performed to evaluate the selection of PAHs stress on the average genome size in a community. We found the distinct communities of significantly larger genome size with the increase of PAHs concentration gradients in soils, and consistent trends were discovered in soils at different latitudes. The abundance of Proteobacteria and Deinococcus-Thermus with relatively larger genomes increased along with PAHs stress and well adapted to polluted environments. In contrast, the abundance of Patescibacteria with a highly streamlined and smaller genome decreased, implying complex interactions between environmental selection and functional fitness resulted in bacteria with larger genomes becoming more abundant. Moreover, we confirmed the increased capacity for horizontal transfer of degrading genes between communities by showing an increased connection number per node positively related to the nidA gene along the concentration gradients in the co-occurrence network. Our findings suggest PAHs tend to select bacterial taxa with larger genome sizes, with significant consequences for community stability and potential biodegradation strategies.
Polychlorinated naphthalene (PCN) concentrations in the soil at an e-waste recycling area in Guiyu, China, were measured and the associated human cancer risk due to e-waste-related exposures was investigated. We quantified PCNs in the agricultural soil and used these concentrations with predictive equations to calculate theoretical concentrations in outdoor air. We then calculated theoretical concentrations in indoor air using an attenuation factor and in the local diet using previously published models for contaminant uptake in plants and fruits. Potential human cancer risks of PCNs were assessed for multiple exposure pathways, including soil ingestion, inhalation, dermal contact, and dietary ingestion. Our calculations indicated that local residents had a high cancer risk from exposure to PCNs and that the diet was the primary pathway of PCN exposure, followed by dermal contact as the secondary pathway. We next repeated the risk assessment using concentrations for other carcinogenic contaminants reported in the literature at the same site. We found that polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and PCNs caused the highest potential cancer risks to the residents, followed by polychlorinated biphenyls (PCBs). The relative importance of different exposure pathways depended on the physicochemical properties of specific chemicals.
Here, a new integrated methodology framework has been proposed for source apportionment and source-oriented risk evaluation, and applied to identify the characteristics, sources and health risks of PAHs in the soils of a typical cold region in Northeastern China. To this end, a large-scale data set containing 1780 soil samples and 16 priority PAHs has been collected from the study area. Two advanced receptor models, positive matrix factorization (PMF) and multivariate curve resolution-weighted alternating least-squares (MCR-WALS), have been comparatively employed to apportion the pollution sources of soil PAHs, with the help of a set of modified literature PAH source fingerprints. Further, the apportionment results have been incorporated into a probabilistic incremental lifetime cancer risk model for assessing the source-specific health risk of soil PAHs. Notably, the PMF and MCR-WALS models have apportioned essentially same results. The coal combustion and gasoline engine are identified as the main contributors of soil PAHs, with contributions of 57.9-58.1% and 25.2-22.2%, respectively. The health risks posed by PAHs in the soils are negligible for both adult and children; relatively, source-oriented risk assessment shows coal combustions make the largest contribution to the total risk of PAHs (56.1%), followed by gasoline engine (22.5%) and coke oven (21.4%).
The current ideas of polycyclic aromatic hydrocarbons (PAHs) in soils are reviewed. Their natural and anthropogenic sources are discussed, and the mechanisms of their arrival from other environmental components to soils are considered. The main processes typical for PAHs in soils are defined; the sorption, degradation, and translocation features of polyarenes in the soil profile are shown. Attention is paid to the geographical features of the PAH distribution in soils. The use of data on the PAHs in soils for the indication of different natural and technogenic processes is also discussed.
The Of/Oh-horizons of 447 forest stands in Germany were evaluated for concentrations and spatial distribution of selected polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). While concentrations of DDT and PCBs show similar spatial distribution patterns for all measured compounds within each compound class, significantly different distributions were identified for concentrations of low-molecular-weight PAHs (2- and 3-ring PAHs plus fluoranthene (FLA) and pyrene (PYR)) in contrast to high-molecular-weight PAHs (4- to 6-ring PAHs without FLA and PYR). Maxima of persistent organic pollutants (POP)-concentrations could be mostly explained by specific locatable sources. Due to the slow degradation rates of these target substances this is especially relevant for historic contamination sources such as extensive 1980s DDT-usage in the former German Democratic Republic and industrial facilities which produced hexachlorobenzene (HCB) or PCBs. A contribution of ubiquitous background pollution derived from long range atmospheric transport is likely for some compounds in the studied area, e.g. DDT in the western part of Germany and dieldrin. However, most target compounds are sourced from local or regional emissions. This is supported by the absence of clear dependencies between POP-concentrations and most environmental and local parameters. We suggest that these results generally reflect the distribution of POPs in densely populated and industrialized countries located in temperate regions.
This paper presents new data on the baseline concentrations of U, Th and K in 2389 stream sediments over the whole
Campania region. These data, based on systematic sampling and analysis, are compared with those obtained by gamma-
ray spectrometry surveys.
Variations in the U, Th and K concentration in the surficial environment of the Campania region appear to be
related to bedrock lithology. Generally, high U, Th and K values in stream sediments correspond well with the occurrence
of volcanic rocks in the central-western part of the region, whereas low values are found in areas characterized by
silico-clastic and carbonate deposits, occurring mostly in the southern and eastern part of the region. Gamma-ray
spectrometry maps show a similar pattern, although the distribution of the highest radioactivity levels define more
restricted areas than the ones resulting from mapping stream sediment geochemistry. Particularly high 40K radioactivity
levels delimit all the known eruptive centers (Roccamonfina, Campi Flegrei and Somma–Vesuvius), including the fissural
sources of Campania Ignimbrites, much better than U and Th radioactivity. One of the concerns for human health
in the Campania region is the total gamma radiation and Rn potential related mostly to alkaline volcanics of the Neapolitan
volcanological province. In particular, geothermal activity occurring in all the Campanian volcanic areas represents
a potential hazard for Rn gas.
Abstract: In recent years, a significant increase in the incidence of male infertility has been observed
and described in the international literature, raising questions about its causes. Several authors have
suggested that exposure to environmental pollution may contribute to a perceived decline in semen
quality worldwide. Although several studies have been conducted about the effects on male fertility
caused by exposure to heavy metals in the workplace, research on the effects caused by continued
exposure to low doses of heavy metals pollution in urban areas is still scarce.
The aim of this study is to identify the relationships between high concentrations of heavy metals and
male infertility in the metropolitan area of Naples. We considered only those elements (Al, As, Cd, Cr,
Cu, Hg, Mn, Mo, Pb, Sb, Tl, Zn) that previous studies have indicated as possible candidates to have some
influence on human semen quality.
We measured semen quality among 600 subjects selected from a sample of 1237 men regularly
examined at the andrology laboratory of the University of Naples "Federico II" for problems related to
male fertility. Using statistical methods the semen data (semen volume, sperm concentration, sperm
total count, sperm motility, pH) were compared with the geochemical distribution of heavy metals in
soils of the Napoli metropolitan area.
Results show a strong correlation between anomalous Pb and Sb concentrations and fertility disorder.
A weaker correlation was also observed with Hg and Zn while the anomalous concentration values of
the other elements (Al, As, Cd, Cr, Cu, Mn, Mo and Tl) appears to have no correlation with male
infertility.
In April 2009, a cement plant located in Sant Feliu de Llobregat (Catalonia, NE Spain) stopped its normal operations. To establish the environmental impact of the facility and the health risks for the population living in the neighbourhood, the concentrations of a number of metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined in soil, vegetation and air samples in three different surveys, which were carried out before and after the facility stopped the cement production. The influence of the cement plant was found to be low in comparison with other potential emission sources in the area, as no decrease in the immission concentrations was noted after the facility ceased its industrial activity. No significant differences were observed in human health risks derived from the exposure to metals and PCDD/Fs before and after the plant ceased the cement production. Risk values for the population living near the facility were similar to those found for residents living in a number of urban and suburban areas.
I am often reminded of the famous saying of Goethe: “Vedi Napoli e poi muori! - See Naples and die!”. Sadly, Naples is now confronted with a number of serious, ongoing problems with a need to alleviate pressure on the worsening environment. One serious problem facing the environment is the presence of the potentially hazardous persistent organic pollutants (POPs), although few systematic studies at regional scale have been conducted. In this study, samples of soil, air, and bulk deposition were collected in Naples metropolitan area (NMA) to characterize the status of POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The results obtained showed that most of these compounds are pervasive in all the studied environmental matrices, especially in some hotspot areas, such as the Bagnoli Brownfield Site and the infamous “Triangle of the Death”, where unwanted ecological risk conditions for PAHs and Endosulfan were determined, respectively. The interactional complexity between urban and the surrounding rural areas was also confirmed, as is the role that urban areas play in the migration and transformation process of POPs. High urban-rural gradients for atmospheric PAHs and PCBs were observed in the NMA, and the urban areas were identified as the emission source of these contaminants. Similarly, the OCP residues, historically originated from the nearby agricultural regions, experience long-term soil re-emission and continuously influence the connected urban environment via atmospheric transport processes.
A probabilistic risk assessment model was developed to explore the health effects of construction dust on the practitioners in the construction industry based on the United States Environmental Protection Agency (USEPA) risk assessment model and the Monte-Carlo simulation method. The health risk was assessed for workers in five zones during the superstructure construction stage of residential projects in Beijing. Health impairment assessment models were applied to translate health risks into disability-adjusted life years (DALYs), which are more intuitive and easy to understand. Sensitivity analysis methods were used to analyse the various exposure parameters and influencing factors that affect the health risk assessment results. The results indicated that workers in the template zone were exposed to the largest health risk, which followed a lognormal distribution of 1.14 × 10⁻⁶±9.43 × 10⁻⁷, and the probability exceeding 10⁻⁶ was more than 40%. The average health risks for workers in the steel, concrete and floor zones were slightly below 10⁻⁶, and the workers in the office zone had the lowest health risk. The spearman rank correlation coefficient method and the full factorial designs method were used for a sensitivity analysis and validation. Sensitivity analysis showed that the sensitivities of the average exposure time (AT), exposure duration (ED), exposure frequency (EF) and concentration (C) were larger, while AT and body weight (BW) exhibited a negative sensitivity. Workers in the template and steel zones had the larger health damage, with an average of more than 0.1a.
To explore the influence of rapid urbanization development on the accumulation of 16 priority PAHs in urban environment, thirty-three surface sediments from city lakes in different urbanized areas of Shanghai were collected to evaluate the occurrence characteristic and source apportionment of PAHs. The concentrations of Σ16PAHs in lake surface sediments ranged from 55.7 to 4928 ng g-1 with a mean value of 1131 ng g-1 (standard deviation, 1228 ng g-1), of which 4-, 5- and 6-ring PAHs were the dominant components. Spatial distribution of PAHs in lake surface sediments showed a significantly declining trend along with a decreasing urbanization gradient (one-way ANOVA, p < .05). Two hotspots of sediment PAHs were mainly distributed at highly urbanized areas with intensive population density and heavy traffic activities and at burgeoning industrial towns in the suburb. Source apportionment of total PAHs identified by a constrained positive matrix factorization model revealed that vehicle emission and combustion of coal, biomass and natural gas were the absolutely predominant sources, respectively accounting for 55.0% and 40.45% of total PAHs burden in lake sediments. Land use regression (LUR) models were successfully developed to evaluate spatial variation of PAHs contamination in urban sediments based on their significant correlations with residential land, commercial land, traffic variables, industrial sources, and population density. All PAH compounds showed strong associations with one or two source indicators (the traffic congestion index and the number of industrial sources), with the fitting R2 varying from 0.529 to 0.984. Our findings suggest that energy consumption related to land use activities obviously promoted PAH accumulations in urban sediment environment during rapid development of urbanization and industrialization in Shanghai.
A systematic grid sampling method and geostatistics were employed to investigate the spatial distribution, inventory, and potential ecological and human health risks of the residues of hexachlorobenzene (HCB) and chlorinated cyclodiene pesticides in soils of the Campanian Plain, Italy, and explore their relationship with the soils properties. The geometric mean (Gmean) concentrations of HCB and cyclodiene compounds followed the order CHLs (heptachlor, heptachlor epoxide, trans-chlordane, and cis-chlordane) > DRINs (aldrin, dieldrin, and endrin) > SULPHs (α-endosulfan, β-endosulfan, and endosulfan sulfate) > HCB. The residual levels of most cyclodienes in agricultural soils were generally higher than those of corresponding counterparts in the other land uses. Significant differences in the concentration of HCB and cyclodienes in the soils across the region are observed, and the Acerra-Marigliano conurbation (AMC) and Sarno River Basin (SRB) areas exhibit particularly high residual concentrations. Some legacy cyclodienes in the Campanian Plain may be attributed to a secondary distribution. The Gmean inventory of HCB, SULPHs, CHLs, and DRINs in the soil is estimated to be 0.081, 0.41, 0.36, and 0.41 metric tons, respectively. The non-cancer and cancer risks of HCB and cyclodienes for exposed populations are deemed essentially negligible, however, endosulfan poses significant ecological risks to some terrestrial species.
This paper reviews the concentration, distribution, source, and potential risk of polycyclic aromatic hydrocarbons (PAHs) in surface soils of China through analysis of data from >6000 surface soil samples in nearly 100 references. The mean value of total 16 PAHs was 730ng·g(-1) in surface soil in China, a relatively lower or moderate level than other countries. Based on the Maliszewska-Kordybach classification criteria, the proportions of heavily contaminated, contaminated, weakly contaminated, and non-contaminated soil samples were 21.4%, 11.9%, 49.5%, and 17.2%, respectively. There was a clear geographical distribution, with concentrations of the total 16 PAHs descending in the following order: Northeast China (1467ng·g(-1))>North China (911ng·g(-1))>East China (737ng·g(-1))>South China (349ng·g(-1))>West China (209ng·g(-1)). Moreover, it was found that the PAH concentrations in surface soil in China descended along the urban-suburban-rural gradient. The concentration and distribution of PAHs were mainly related to the degree of economic development, population density, climatic conditions, and soil organic matter, and the divergence of regional economic patterns and climatic conditions was the main reason for the observed PAH distribution in the soils. Traffic emissions, coal and biomass combustion mainly contributed to the PAH contamination of surface soil in China during the process of urbanization and industrialization, and the average Benzo(a)pyrene equivalent concentration of ∑PAH7c (seven carcinogenic PAHs) was 99ng·g(-1), which indicated the soil samples had a small potential carcinogenic risk. Despite soil pollution being generally low, PAH concentrations in some areas were relatively high, therefore it is necessary to produce strategies, such as establishing effective guidelines and developing environmental-friendly technology to reduce PAH emissions, and prevent further contamination.
Urbanization may cause increased exposure levels to polycyclic aromatic hydrocarbons (PAHs) and associated health risks for over half of the world's population living in cities, but little evidence has shown a direct spatial relationship between urbanization and soil PAH pollution. Based on the monitored PAH concentrations in 188 topsoil (0–5 cm) samples in Shenzhen, the most rapidly developing city in China, in recent decades, we applied geographical demarcation to determine the occurrences, source apportionments, and spatial ecological risks of soil PAHs across five zones of varying urban densities. Mean concentrations of the 16 US Environmental Protection Agency (EPA) priority PAHs (∑16PAHs) and the 7 carcinogenic PAHs (∑7CarPAHs) both followed the order: Zone D (60%–80% constructive land density (CLD)) > Zone E (80%–100% CLD) > Zone C (40%–60% CLD) > Zone B (20%–40% CLD) > Zone A (0%–20% CLD), suggesting that the highest PAH levels occurred in the suburban-urban center transitional zone (Zone D) rather than the urban center zone (Zone E) in Shenzhen. There were significant correlations of ∑16PAHs to TOC and sampling altitude across all samples but not within highly-urbanized regions (Zones D and E), implying a considerable disturbance of urbanization to the soil PAH pool. Source apportionments suggested that soil PAHs of all zones were mainly derived from fossil fuel combustion, with Zone E showing the highest contribution from oil sources among different zones. Spatial ecological risk analysis showed that the contaminated area (467 km2; 23.9% of total area; toxic equivalency quotients > 33 ng g−1) had a higher contribution from the highly-urbanized regions (Zones D and E) than the uncontaminated area (42.3% vs. 18.1%). Overall, our study highlighted a strong spatial relationship between urbanization and soil PAH pollution.
Polycyclic aromatic hydrocarbons (PAHs) are a major class of environmental pollutants mainly arising from anthropogenic activities. In this paper, the behavior and the distribution patterns of sixteen PAHs, listed as priority pollutants by the United States Environmental Protection Agency, were evaluated in 119 soil samples collected in different areas of Campania region in the southern Italy. The observation of the geochemical distribution patterns showed that both high and low molecular weight PAHs are mostly concentrated within the metropolitan area of Naples, the Agro Aversano area, and, partly, the Sarno River basin. In accordance with the Italian environmental law (D. Lgs. 152/2006), these areas should be considered potentially contaminated and not suitable for a residential use unless an environmental risk analysis does not demonstrate their safety. As a consequence, a preliminary quantitative risk assessment enhanced by the use of GIS was run revealing the existence of an incremental lifetime cancer risk higher than 1 × 10(-5) for the city of Naples and for some other populous areas.
Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool.
Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool.
Emission factors for 19 polycyclic aromatic hydrocarbons were measured during wind tunnel simulations of open burning for agricultural and forest biomass fuels including cereal grasses, agricultural tree prunings, and fir and pine wood (slash). Yields of total PAH varied from 5 to 683 mg kg{sup -1} depending principally on burning conditions and to a lesser extent on fuel type. Barley straw and wheat straw loaded at 400-500 g m{sup -2} emitted much higher levels of PAH, including benzo[a]pyrene, than other cereal and wood fuel types burning under more robust conditions. As anticipated, total PAH emission rates increased with increasing particulate matter emission rates and with declining combustion efficiency. 20 refs., 2 figs., 6 tabs.
Sources of polycyclic aromatic hydrocarbons (PAHs) to the Hudson River Estuary Airshed were investigated using positive matrix factorization (PMF). A three-city dataset was used to obtain common factor profiles. The contributions of each factor on each sampling day and site were then determined, and a sensitivity analysis was conducted. A stable eight-factor solution was identified. PMF was able to identify a factor associated with air–surface exchange. This factor contains low-molecular weight PAHs and was a dominant contributor to the measured PAHs concentrations. Factors linked to motor vehicle use (diesel and gasoline vehicle emissions and evaporative/uncombusted petroleum) and natural gas combustion were also major contributors. Motor vehicle combustion and oil combustion factors were the predominant contributors to particle-phase PAHs, while natural gas combustion, air–surface exchange, and evaporative/uncombusted petroleum factors made substantial contributions to gas-phase PAH concentrations. In contrast to fine particulate matter (PM2.5), which is dominated by regional transport, spatial variations in PAH concentrations suggest that PAH concentrations in the Hudson River Estuary Airshed are dominated by sources within the New York–New Jersey urban–industrial complex.