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Distribution, fate and risk assessment of PAHs in water and sediments from an aquaculture- and shipping-impacted subtropical lake, China
Abstract
The spatial-temporal distribution of polycyclic aromatic hydrocarbons (PAHs), their source, and potential health risks were determined in overlying water and surface sediments from Chinese Lake Guchenghu, adjacent commercial mitten crab ponds and the connected Wushen Canal to assess the contamination profile of the area. The total PAHs concentrations in sediment and water were 86.7-1790 ng g-1dry weight (dw) and 184-365 ng L-1in summer and 184-3140 ng g-1dw and 410-1160 ng L-1in winter. Two- and 3-ring PAHs were the predominant compounds in water, while PAHs with 4-6 rings dominated in the sediment at both upstream and downstream sites. PAHs concentrations in water and sediment correlated significantly. Diagnostic ratios and positive matrix factorization (PMF) analyses indicated a strong influence of pyrogenic sources, principally biomass combustion and vehicle emission, on the concentrations of PAHs. The distribution, source identification, and mean effects range median quotients (mERMQ) analyses suggested that the most contaminated area was located downstream and upstream of the Wushen Canal, followed by Lake Guchenghu and a commercial crab pond area. From an ecological point of view, PAHs posed a potential risk to drinking water sources as the concentrations exceeded the guideline value of 0.05 μg L-1. The risk posed by sediment PAHs appeared to be low except for the downstream sites, which showed a low to medium ecotoxicological risk. The total incremental lifetime cancer risks ranged between 10-7and 10-5, indicating a potential health risk for the local population when exposed to sediment from the area.
... Low molecular weight (LMW) PAHs with relatively higher vapor pressure would more likely diffuse to the atmosphere than other PAHs (Zhang et al., 2022). Due to strong adsorption capacity for PAHs, soil organic matters (SOM) and clay content could greatly affect environmental behavior of PAHs in soils (Liu et al., 2011;Wang et al., 2018;Zeng et al., 2018). Land use pattern can also affect the distribution of PAHs . ...
... As results, they may not be originally or only partially adhered to the soil particles, which was responsible for the lack of correlation between OM and LMW-PAHs (Choi, 2014). Meanwhile, the strong relationships between OM/TOC with HMW-PAHs had been widely reported in previous literature (Liu et al., 2011;Xiao et al., 2014;Zeng et al., 2018) due to significant impact of OM/TOC on the sorption, sequestration, and fate of PAHs in soils. TN was positively significantly correlated with OM and showed the same impact on the PAHs in soils, revealing TN was another key factor for the distribution of PAHs. ...
... As shown in Fig. S4a, 70.6% of Flu/(Flu + Pyr) and 51.1% of InP/(InP + BghiP) were higher than 0.5, while 24.4% of Flu/(Flu + Pyr) was observed in the range of 0.4-0.5 and 48.3% of InP/(InP + BghiP) was found to be in the range of 0.2-0.5. Additionally, the ratio of BaA/(BaA + Chr) under 0.2, between 0.2 and 0.35, larger than 0.35 indicated PAHs originated from pyrogenic, mixed, and petrogenic contaminations, respectively (Zeng et al., 2018). The corresponding percentages were 22.1%, 45.5%, and 32.4%, respectively (Fig. S4b). ...
Polycyclic aromatic hydrocarbons (PAHs) in urban environments have been globally concerned due to their significant health impacts on residents. However, little is known about potential risks of PAHs from centralized water source areas. In the present study, 326 soils samples from the main water source areas of Beijing were collected and the occurrence, source appointment, and risks of PAHs were systematically investigated based on the monitoring results from high-performance liquid chromatography (HPLC). The total PAHs (∑16 PAHs) concentrations ranged from 5.70 to 1512 ng/g with median value of 44.2 ng/g, in which 4-ring and 5-ring groups were the major components. PAHs concentrations in the cultivated land were significantly higher than other areas, which could reflect significant impact of soil organic matter and total nitrogen contents on the spatial variations of PAHs. Further source identifications through positive matrix factorization model (PMF) revealed that biomass (22.5%), coal (21.4%), gasoline (17.6%) and diesel (16.4%) combustion were dominant sources of soil PAHs in the study area. Moreover, the risk assessment indicated that total ecological and health risk of PAHs were negligible, but individual PAH, including pyrene and benzo(b)fluoranthene, should be concerned due to their potential risks in several monitored stations located in the secondary protection area of four reservoirs. Our study provided new insights into environmental risks of soils in main water source areas from PAHs and could be helpful for organic micropollutant controlling and drinking water safety in rapidly urbanizing cities.
Graphical abstract
... anthracene (DahA), indeno [1,2,3-cd]pyrene (IcdP), and benzo [g,h,i]perylene (BghiP) (Zhao et al. 2021). The origin of PAHs in the environment can be from both natural processes (diagenesis, volcanic eruptions, forest and prairie fires, etc.) and anthropogenic processes (fossil fuel combustion, vehicle emissions, coal and wood burning, industrial processes, etc.) (Yunker et al. 2002;Tobiszewski and Namiesnik 2012;Zeng et al. 2018). PAHs can be classified into 2 to 6 rings depending on their molecular structure and composition. ...
... PAHs can be classified into 2 to 6 rings depending on their molecular structure and composition. Due to the differences in hydrophobicity and octanol-water partition coefficient of PAHs with different rings, their distribution in different media is diverse (Zeng et al. 2018). Low molecular weight (LMW) (2-to 3-ringed) PAHs typically predominate in water, whereas medium molecular weight (MMW) (4-ringed) PAHs and high molecular weight (HMW) (5-to 6-ringed) PAHs tend to be absorbed in solid phase for longer period of time, leading to the accumulation in sediments Xie et al. 2020). ...
... As a result, PC1 can be defined as a mixed source of petroleum-derived residues and combustion. PC2 was associated with 22.93% of the total variance and received high loading for Fla, Chr, and DahA, which represent coal combustion (Zeng et al. 2018). Therefore, PC2 represented the source of coal combustion. ...
Purpose
A comprehensive study was conducted to investigate the presence, geochemical characteristics, and behaviors of polycyclic aromatic hydrocarbons (PAHs) in soil, water, and sediment near a typical nonferrous smelter.
Methods
A total of 50 samples were collected and analyzed by gas chromatograph-mass spectrometer (GC–MS) for the presence and levels of 16 PAHs. Molecular diagnostic ratios (DRs) and principal component analysis—multiple linear regression analysis (PCA-MLR) were used to determine the source apportionment of PAHs. Fugacity model was used to estimate the exchange and migration between sediment and water. The toxic equivalent quantity (TEQ) and risk quotient (RQ) were applied to determine potential risk.
Results
The concentration of Σ16PAHs in soil ranged from 44.62 to 2547 ng g⁻¹ (mean 629.6 ± 664.4 ng g⁻¹) and consisted mainly of 4- to 5-ringed PAHs. The concentration of Σ16PAHs in water ranged from 20.34 to 702.7 ng L⁻¹ (mean 97.63 ± 152.9 ng L⁻¹), mainly consisting of 2- to 3-ringed PAHs. The highest concentrations of Σ16PAHs were found in sediments, which ranged from 44.52 to 6040 ng g⁻¹ (mean 1537 ± 1698 ng g⁻¹) and mainly consisted of 4- to 6-ringed compounds. PCA-MLR analysis identified three, two, and three principal components in soil, water, and sediment with a cumulative variance of 94.23%, 90.09%, and 87.48%, respectively. The result of sediment–water exchange showed that the low molecular weight (LMW) (2- to 3-ringed) PAHs were essentially in equilibrium between sediment and water, while the medium molecular weight (MMW) (4-ringed) and high molecular weight (HMW) (5- to 6-ringed) PAHs tended to sink from the water to sediments.
Conclusion
The sources of PAHs were slightly different in different media and different ring numbers. Coal combustion and traffic emissions from industrial activities of smelters were the primary contributors. The highest concentration levels of Σ16PAHs were found in sediment, followed by soil and water. In this area, sediments would serve as a sink more than a source of PAHs and sediments were potentially at environmental risk. Therefore, more attention should be paid to the sediment.
... Until now, there has been no information on the health risks of PAH exposure. In general, the incremental lifetime cancer risk (ILCR) defined by the US Environmental Protection Agency (US EPA) can assess the potential carcinogenic risks and quantify the health risks of PAH exposure through different exposure routes (Zeng et al., 2018;Famiyeh et al., 2021). Therefore, the analysis of PAHs in surface sediments of ports is important for elucidating their pollution status, sources, and associated risks (Iwegbue et al., 2021). ...
... Skin contact is likely the main route of exposure to PAHs in sediments. In addition, inadvertent non-dietary ingestion of sediments may be a route of exposure, such as hand-to-mouth or object-to-mouth transfer of sediments on surfaces of objects (Wilson et al., 2015;Zeng et al., 2018;Deziel et al., 2019;Iwegbue et al., 2021). The ILCR due to ingestion and dermal exposure can be estimated using Eqs. ...
... PMF is a multivariate method that is widely used to distinguish the potential sources of PAHs and their contributions (Zeng et al., 2018;Davis et al., 2019;Wang et al., 2020). In this study, a dataset of 16 PAHs concentrations and uncertainties in sediments from 26 sites were used as the input data for the PMF model. ...
The accumulation of pollutants in the semi-enclosed waters of ports has long been a concern. This study assessed the pollution status, sources, and toxicity risks of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments of 7 major ports in Taiwan. Total PAHs concentrations in sediments ranged between 8.4 and 572.5 ng/g dw, with an average of 112.4 ± 136.5 ng/g dw. The 3- and 4-ring PAHs (63 %) were the major constituents of PAHs in the sediments. Diagnostic ratios and positive matrix factorization analyses indicated that PAHs in sediments were mainly contributed by biomass combustion (45.0 %), coal combustion (31.5 %), and vehicle emissions and related fossil fuels (23.5 %). The results of ecological risk assessment showed a low–medium risk of PAHs in the sediments outside the port, whereas most of the sediments within the port presented a medium–high risk. An assessment of the possible human health risks indicated that PAHs were present at acceptable levels.
... The blank determination was carried out using triply distilled water was used instead of the sample to determine the blank. Table 1 [44] in a study on [46,47,48].Fluoranthrene which has been grouped into a class 3 carcinogenic compound [49]was detected in all the bore hole water, surface water and sediment samples. It is also of a great concern that benz(a)anthracene, a confirmed carcinogenic compound [50]was not only detected in all the water resources, but present at concentrations higher than 0.002 Mg/L permissible limit of WHO. ...
... Fluoranthrene, which has been classified as a class 3 carcinogenic compound [45,48] was distributed at varying but higher concentrations in the water and sediment samples. Fig. 4 [59 . ...
Polycyclic aromatic hydrocarbons (PAHs) are of global concern due to their harmful effect on the health of human and the environment. They are known as persistent organic pollutants and linked to severe health effects in humans and ecosystem. This study aimed to investigate the presence and types of these hydrocarbons including assessing their distributions in groundwater water, surface water and sediment in Igbokoda, Irele and Okitipupa coastal areas of Ondo State, Nigeria. The watersamples were extracted with liquid-liquid extraction while the sediment samples were extracted with an ultrasonic bath extractor. The extracts were cleaned with alumina as adsorbent and analyzed using a gas chromatograph coupled to a mass spectrometer. The results showed wide variations in the concentrations of the analytes of interest in the different matrices studied. The total mean concentration range of these pollutants in the samples from the well, borehole, surface water, and the sediment were: 0.15 ± 0.31, 0.11±0.52 to 0.90± 0.28, 0.05±0.02 to0.11±0.52 and 0.16±0.14 to0.21±0.17, respectively. The result revealed that the concentrations of most of these contaminants were higher than the maximum permissible limit of PAH in drinking water and sediment. The contamination level was higher in the borehole water source than the others. The study concluded that all the investigated matrices were contaminated with these pollutants. The study recommended the enactment of new laws of regulating activities leading to the emissions of these pollutants by the Nigerian government inorder to safeguard the environment and human health.
... Seasonal variations in the contents of 30 PAHs and 16 priority PAHs in sediments were found to be significantly different (P < 0.01), with higher concentrations observed during the dry season (mean 1200 ng/g dw and 857 ng/g dw) compared to those in the wet season (mean 743 ng/g dw and 634 ng/g dw) (Fig. 2a). This trend was consistent across sediments from the Three Gorges Reservoir, Wushen Canal, Haihe River, and estuarine areas in China, as reported in previous studies (Li et al., 2021b;Lin et al., 2018;Liu et al., 2023b;Zeng et al., 2018). One possible explanation for this phenomenon is the influence of heat sources generated by particles in lower-temperature environments, which become deposited and accumulated in sediments during the dry season (Liu et al., 2019). ...
The construction of dams has caused disruptions to river connectivity, leading to alterations in the deposition of hydrophobic organic contaminants in reservoir sediments. Further investigation is warranted to explore the impact of cascade reservoirs with differing hydrological characteristics on polycyclic aromatic hydrocarbons (PAHs) distribution in sediment. This study examines the presence of 30 PAHs in the sediments collected from six cascade reservoirs situated in the Wujiang River basin during January and July 2017. The results showed that Σ30 PAHs ranged from 455–3000 ng/g dw (mean 1030 ng/g dw). Anthropogenic activities and reservoir hydrology determined the distribution trend of PAHs in sediments, with an overall increase from upstream to midstream and then a decrease downstream. The PAH levels were highly linked to the secondary industry (P < 0.05). This was further supported by the relationship between the PAH emissions from coal combustion and traffic sources analyzed by the positive matrix factorization model and economic parameters in the wet season (P < 0.01). At the same time, reservoir age (RA) showed a positive correlation with PAH concentrations (P < 0.05), while hydraulic retention time (HRT) exhibited a negative correlation with PAH levels (P = 0.03). The relationship between total organic carbon (TOC) and PAHs in stream sediments worldwide was nonlinear (P < 0.01), with PAH concentrations initially rising and then falling as TOC levels increased. Concerns regarding carcinogenic risk were raised due to contributions from coal and vehicular sources, with the risk increasing with RA.
... The existence of river-type reservoir could change the original hydrological conditions of the river and potentially affects the occurrence characteristics of pollutants in the basin. However, previous studies mainly focused on the occurrence of PAHs in some individual rivers (Liu et al., 2016;Tongo et al., 2017), reservoirs (Tan et al., 2019;Zhu et al., 2015) and lakes (Meng et al., 2019;Zeng et al., 2018). Few attention had been paid on PAHs in the river-reservoir system, and the dispersion and transport behaviour of PAHs along the environmental gradient from the river to reservoir is still unknown. ...
Rivers and downstream reservoirs formed a connected river-reservoir system that played an important role in regulating the aquatic environment. The polycyclic aromatic hydrocarbon (PAH) pollution in individual river or reservoir has caused widespread concern. However, the distribution and potential environmental behaviour of PAHs in the river-reservoir system are still scarce. This study focused on the occurrence, distribution, and risk assessment of PAHs in a representative river-reservoir system in South China. The concentration of Σ 16 PAHs in the water phase of the river-reservoir system was 102.2 − 407.6 ng/L and at a low level compared to other typical aquatic environment, with the main monomer being naphthalene. The PAHs in the river system were mainly from the volatilization of petroleum products, while they were from combustion and petroleum volatilization sources in the reservoir system. For the river system, higher runoff and temperature could contribute to the volatilization of low molecular weight PAHs and their solubility in the water phase. In contrast, longer hydraulic retention time in the reservoir system could reduce the occurrence level of 3-ring PAHs through the biogeochemi-cal cycles. Redundancy analysis further indicated that significant factors affecting PAHs in river system and reservoir system were different. In common, the water temperature could influence the PAHs both in the river system and reservoir system. Generally, the ecological risk of PAHs in the water phase was at a moderate risk and their health risk was at a low risk.
... pose cause to human health and ecosystems (Falciglia et al., 2018;Zeng et al., 2018). ...
This study systematically analyzed the distribution characteristics, sources, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in Kuye River sediments, located in an energy and chemical industry base in northern Shaanxi, China. The results that revealed the concentrations of 16 PAHs in the sediment ranged from 1090.04 to 32,175.68 ng∙g⁻¹ dw, with the four-ring PAHs accounting for the highest proportion. Positive matrix factorization analysis (PMF) revealed the main sources of PAHs as incomplete fossil fuel combustion, biomass combustion, and traffic emissions. The total toxic equivalent concentration of BaP, risk quotient, and lifetime carcinogenic risk of PAHs suggested moderate to high contamination of PAHs in the area. The higher incremental lifetime carcinogenic risk (ILCR) indicated that PAH ingestion was the primary route of impact on public health, with children potentially being more susceptible to PAH exposure. This study can provide valuable theoretical support for implementing pollution prevention measures and ecological restoration strategies for rivers in energy and chemical industry areas.
... The total concentration of PAHs in the SR Harbor water was high when compared to other studies that have analyzed these compounds in freshwater environments. For example, in freshwater environments, values can range from 5.56 to 266.1 ng L − 1 (Zhi et al., 2015), 175-325 ng L − 1 (Sun et al., 2017), 184-1160 ng L − 1 (Zeng et al., 2018), and 2.33-25.83 μg L − 1 (Tongo et al., 2017). ...
... PAHs possess distinctive attributes, including hydrophobicity, low vapor pressure, and high octanol/water partition coefficients. These properties promote the adsorption of particles, transportation, transformation, and accumulation in sediments [9][10][11]. The contamination of PAHs in modern environments is usually linked to human industrial and agricultural production activities, such as fossil fuel emissions (coal, oil, and natural gas) and biomass burning [12][13][14][15]. ...
... On the other hand, HMW-PAHs contain four or more aromatic rings, such as pyrene and benzo [a]pyrene. The HMW-PAHs are larger in size compared to LMW-PAHs, have higher molecular weights, and are generally less volatile (Zeng et al., 2018). LMW-PAHs are more soluble in water and can readily enter the atmosphere, whereas HMW-PAHs tend to be more hydrophobic and have a greater tendency to adsorb onto particles or sediment (Niu et al., 2021). ...
This research focused on investigating the contamination levels, sources, and potential ecological and human health risks associated with 16 polycyclic aromatic hydrocarbons (PAHs) present in surficial sediments of the Abadan freshwater resources in the northwest of the Persian Gulf. The concentrations of ∑16PAHs varied between 67.8 and 57,748 ng/g with an average of 8222 ng/g. Approximately 30 % of the ∑16PAHs were attributed to seven carcinogenic PAHs. The predominant components of the PAHs found in the sediments were the 3- and 4-ring PAHs, which accounted for approximately 63 % of the total PAHs present in the surficial sediments. The diagnostic ratios and principal component analysis (PCA) indicate that the PAHs detected in the sediments originated from various sources, including traffic emissions, coal, and biomass combustion, petroleum leakage, and wastewater. According to our ecological risk assessment, substantial harm to the biota was observed in the Arvand River. An assessment of cancer risk indicated that both adults and children in Abadan area are exposed to a considerable cancer risk due to the presence of PAHs. In conclusion, ongoing monitoring of PAH pollution and implement measures to protect freshwater ecosystems near the Persian Gulf are essential.
... Cd 2þ in aquaculture ponds may come from road dust and runoff (Pal & Maiti 2018). PAHs, on the other hand, come from biomass combustion and vehicle emissions (Wang et al. 2010;Zeng et al. 2018). Wang et al. (2023b) found that biochar prepared from seabed moss was used to improve water quality in aquaculture ponds, and the removal efficiencies of seabed moss biochar for Cd 2þ and PAHs were 49, 88, 90, 91, and 88%, respectively. ...
Aquaculture produces numerous by-products like aquatic plants, algae, and nutrient-enriched sediment annually, which are often discarded as waste, are not environmentally friendly, and are harmful to the environment. In this study, aquaculture by-products were utilized to prepare moss biochar at 500, 700, and 800 °C (BC500, BC700, and BC800, respectively); Elodea biochar (WBC800) at 800 °C; and sediment biochar (SBC800) at 800 °C. Characterization and experimental results showed that BC800 had the best adsorption effect on geosmin (GSM) under the same conditions; when using BC800 to treat GSM solution with a pH of 7, the adsorption efficiency of GSM was high (97.08%) under the conditions of dosage of 1.0 g, temperature of 25 °C, and adsorption time of 2 min. Adsorption is a multimolecular layer process that involves both physical aspects of porous adsorption and connections between chemical bonds. Biochar, derived from aquaculture by-products, is utilized to eliminate odorous substances in aquaculture environments, thereby promoting resource recycling.
... As shown in Fig. 2c-d, the PAHs containing three benzene rings dominated in all 11 seawater sampling sites, accounting for 53.82-60.67% of the total PAHs; whereas the PAH containing two, four, five and six benzene rings accounted for 10.56%, 26.90%, 4.14% and 1.79% of the total PAHs, respectively. The main contributing monomer was Phe, which was commonly thought to be associated with frequent maritime traffic and ship fuel leakage [62]. ...
Most PAHs produced by human activities can be absorbed and accumulated by edible organisms and pose a potential hazard to human health. However, the source apportionment and human health risk of PAHs accumulated in edible organisms remains largely unknown. Therefore, we conducted source analysis and health risk assessment based on the PAH concentrations in ten marine fish from coastal areas of Guangdong, China. Results showed that the pollution of PAHs in fish organisms was at "Minimally polluted" level, and that all marine fish had the ability to accumulate PAHs. Risk assessment indicated Carcinogenic risk of PAHs in four populations was at a "Cautionary risk" level, with urban children suffered the highest risk. Petroleum pollution, Coal and biomass combustion, and Marine transport emissions were identified as the main anthropogenic sources for PAHs in organisms, and Marine transport emissions accounted for the highest Carcinogenic risk. The Acceptable daily intake for all populations were far below their actual daily intake without causing "Cautionary risk". Our findings provide new insights into the source apportionment and health risk of PAHs from a "source-organism-human" perspective, and suggested that joint management of three anthropogenic sources would be an effective way to prevent the health risks of PAHs.
... They are persistent, toxic, carcinogenic, mutagenic and teratogenic and most of them can cause DNA damage [8][9][10][11]. PAHs are colourless to white or pale yellowishgreen in colour due to its low solubility and high octanol-water partition coefficient and undergo long-range transport it accumulates in organisms [12][13][14]. In contrast to heavy molecular weight PAHs found in particulate matter, low molecular weight PAHs are more volatile and thus easily discovered in the gaseous phase, and they are less carcinogenic [15]. ...
Polycyclic aromatic hydrocarbons (PAHs) profile by gas-chromatography-mass spectrometry were recently used for the identification of sources of contamination in environmental forensic investigations. In present study, an effort is given to utilize gas chromatography-mass spectroscopy to obtain PAHs profile that could help forensic scientist in selection of evidence at the scene of fire. In forensic laboratories, the main evidence received in fire burning cases are fire debris which consists of soil, wood, paper, cloth etc. as a piece of individual evidence or mixture. In fire investigation, the type of material collected from the crime scene affects the investigation hence present study focused on which type of material is more suitable while utilizing a polycyclic aromatic hydrocarbon as a source identifier. Total of nine different materials like paper, cardboard, foam, cloth, metal, hair, soil, meat and wood were selected and these are burned with gasoline in partial burning and complete burning conditions. Debris obtained sonicated at room temperature and concentration of 18 PAHs were determined with gas chromatography-mass spectrometry. Results obtained were analyzed with the Principal Component Analysis (PCA) technique to generate a profile of PAHs. It is concluded that partially burned samples provide more information about the use of ignitable liquid to commit the crime as compared to completely burned samples. The meat, hair, metal and soil material provide more information about the presence of ignitable liquid based on the 18 PAHs concentration profile.
... According to the water environmental quality standards of China (GB3838-2002), the highest BaP concentration was below the safety threshold (2.8 ng/L), indicating a low potential threat to ecological environment and human health. Compared with other lakes and rivers in China, the pollution level of East Lake was lower than lakes in northeast China such as Mopanshan Reservoir (Liu et al., 2013), eastern China, such as Gucheng Lake (Zeng et al., 2018) and Poyang Lake (Zhi et al., 2015). Compared with the existing studies, the pollution level of PAHs in the water of East Lake was at a relatively lower level in China (Meng et al., 2019). ...
The pollution of microplastics (MPs) and polycyclic aromatic hydrocarbons (PAHs) in the environment is a global problem, which has attracted extensive attention of many researchers. In present study, MPs and PAHs are investigated to study the impact of human activities and their possible relationship in China's second largest urban lake, East Lake. The abundance of MPs are 3329.19 ± 2059.26 particles/m3 and 2207.56 ± 1194.04 particles/kg in water and sediment, respectively. MPs are predominantly characterized by fibers, polypropylene (PP) and polyethylene (PE), colorlessness in water and sediment. The abundance of MPs in water with frequent human activities is higher, which is reversed in sediments, indicating that disturbance is not conducive to the enrichment of MPs in sediments. The concentration of 16 PAHs are 36.95 ± 13.76 ng/L and 897.08 ± 232.34 ng/g in water and sediment, respectively. PAHs in water are mainly 2-3-ring, while there are 4-ring PAHs in sediments. The good corresponding relationship between MPs and PAHs indicates that human activities have an important impact on the distribution of pollutants compared to the interaction of pollutants. In addition, the significant positive correlation between lakeshore length and water MPs abundance indicates that surface runoff may be an important source of water MPs. The pollution load index shows that MPs in sediment has reached moderate to severe pollution level, while the water is slightly polluted level. The potential ecological risk assessment results show that more than half of the sediment sites are at dangerous to very dangerous ecological risk level.
... PAHs are a large group of persistent, toxic, genotoxic, and carcinogenic environmental contaminants (Shen et al., 2013;Han and Currell, 2017). Based on their characteristics and molecular weights, PAHs can be divided into two categories which are low molecular weight (LMW) compounds with two or three benzenoid rings that typically predominate in the water body and high molecular weight (HMW) compounds with four to six benzenoid rings that are prevailing in sediments medium (Zeng et al., 2018). Due to their potential mutagenicity, toxicity, and/or carcinogenicity to humans' health, several PAHs are categorized as priority pollutants (USEPA, 2014;Zelinkova and Wenzl, 2015). ...
This study presented for the first time a comprehensive measurement campaign of 16 PAHs along the Euphrates River for five months, in both water and sediment samples. Our study revealed that the PAHs contamination increased along the flow direction due to the increasing non-point pollution and the return flows of agriculture. The 5-6 rings PAHs were dominant in water and sediment samples with an average of 42 % and 50 %, respectively. The diagnostic ratios of PAHs suggest that the pollution of these compounds originated mainly from petroleum product combustions. The carcinogenic PAHs formed 46 % and 55 % of the total measured compounds in water and sediment samples, respectively, which highlights potential ecological and human health risks. Based on sediment quality guidelines (SQGs), most sites exhibit an effect range between low and medium. The calculated incremental lifetime cancer risk (ILCR) for adult and children were in the 10 − 2-10 − 3 range, which is 3-6-fold higher than what was reported in the literature. These observations call for urgent attention from environmental authorities of countries sharing this key water source in Western Asia.
... PAHs have been found to be widespread in the natural environment, mainly originating from human activities, such as oil leakage, incomplete combustion of organic matter (coal, oil, wood), steel production, industrial emissions (Li et al., 2015Suman et al., 2016). Owing to their hydrophobic and lipophilic nature (Zeng et al., 2018), PAHs in the atmosphere and rivers are prone to adsorption on suspended matter and ultimately settling in river sediments and soils. River sediments and soils serve as the source as well as the sinks of various pollutants, with low spatiotemporal variation (Li et al., 2015). ...
This study systematically analyzed the contents, compositions, and sources of polycyclic aromatic hydrocarbons (PAHs) in river sediments near an important energy and chemical base in northwest China. In addition, their possible adverse effects on the ecology and human health were assessed. The PAH concentrations in this study area ranged from 2641.28 to 16783.72 (ng/g dw). PAHs of medium molecular weight (3-ring and 4-ring) showed the largest proportion, followed by PAHs of higher molecular weight (5-ring and 6-ring). The results of molecular diagnostic ratios and principal component analysis revealed that PAHs in the region have complex sources, with incomplete combustion of local fossil fuels and traffic exhaust factors being the main sources. The total toxic equivalent concentration of PAHs varied from 10.05 to 760.26 ng/g, and according to the sediment quality guidelines, PAHs have high potential ecological risk in the lower reaches of the river. The mean effect range-median quotient for the region was 0.46, and the combined ecological risk was at moderate to high levels (21% probability of toxicity). The lifetime carcinogenic risks for adults and children exposed to PAHs were 2.95 × 10−3 and 1.87 × 10−2, respectively, which are much higher than the limit of 10−4, indicating moderate to high potential cancer risks. Therefore, the local government should consider taking some environmental remediation measures. This study can provide theoretical support for pollution prevention measures and ecological restoration strategies for rivers in resource-rich areas.
Graphical abstract
... Otherwise, higher concentrations were observed in farming areas near to urbanized regions in Brazil such as BSCI (C. gigas, range from 19-1594 ng g − 1 dry weight) (Souza et al., 2012;Flores-Nunes et al., 2015), Laguna Estuarine System (Crassostrea gasar, range from 407-1976 ng g − 1 dry weight) (Ferreira et al., 2020; and worldwide as Guangdong-China (Crassostrea rivularis, range from 231-1178 ng g − 1 dry weight) (Yu et al., 2016), Lake Guchenghu-China (surface waters, 410-1160 ng L − 1 ) (Zeng et al., 2018). Of the 16 priority PAHs' monitored in the present study (Supplementary Table 2), 3 of them showed a significant difference between the areas (Fig. 2). ...
Anthropogenic activities in coastal regions cause risks to the environmental and human health. Due to the carcinogenic and mutagenic potential, polycyclic aromatic hydrocarbons (PAH) are considered priority for monitoring. Most of the Brazilian production of Crassostrea gigas oysters are placed in the Bays of Santa Catarina Island. The aim of this study was to evaluate molecular responses (phase I and II of biotransformation and antioxidant defense) of C. gigas from six oyster farming areas potentially contaminated by sanitary sewage in Florianópolis Metropolitan (SC, Brazil): Santo Antônio de Lisboa, Sambaqui, Serraria, Caieira, Tapera, Imaruim. We evaluated the transcript levels of CYP1A1-like, CYP2-like, CYP2AU2-like, CYP356A1, GSTA1A-like, GSTO.4A-like, SULT-like, SOD-like and CAT-like by qRT-PCR. Only oysters from Caieira showed levels of thermotolerant coliforms allowed by the law. Chemicals analyses in soft tissues of oysters showed low to average levels of PAH in all monitored areas. Enhanced transcript levels of phase I (CYP1A1-like, CYP3564A1-like, CYP2-like and CYP2AU2-like) were observed in oysters from Serraria and Imaruí, suggesting higher biotransformation activity in these farming areas. Regarding phase II of biotransformation, GSTO.4A-like was up-regulated in oysters from Imaruí compared to Caieira and Santo Antônio de Lisboa. An upregulation of SOD-like and CAT-like were observed in oysters from Imaruí and Serraria, suggesting that oysters from these sites are facing higher prooxidant conditions compared to other areas. By integrating the biological and chemical data it is suggested that human-derived contaminants are affecting the oyster metabolism in some farming areas.
... Factor 3, accounting for the highest proportion (80%) of PAH concentrations, was mainly composed of Acpy, Acp, and Flu. This factor profile was of high consistency with PAH emission characteristics from gasoline and diesel combustion (Zeng et al., 2018). As shown in Figure S3 in Supporting Information S1, the PAH profile of the field blank showed some similarity to factor 3, revealing the onboard contamination may partly come from the emission from the vessel's diesel-based engines. ...
In the Arctic Ocean, it is still unclear what role oceanic transport plays in the fate of semivolatile organic compounds. The strong‐stratified Arctic Ocean undergoes complex inputs and outputs of polycyclic aromatic hydrocarbons (PAHs) from the neighboring oceans and continents. To better understand PAHs’ transport processes and their contribution to high‐latitude oceans, surface seawater, and water column, samples were collected from the North Atlantic Ocean and the Arctic Ocean in 2012. The spatial distribution of dissolved PAHs (∑9PAH) in surface seawater showed an “Arctic Shelf > Atlantic Ocean > Arctic Basin” pattern, with a range of 0.3–10.2 ng L⁻¹. Positive matrix factorization modeling results suggested that vehicle emissions and biomass combustion were the major PAHs sources in the surface seawater. According to principal component analysis, PAHs in different water masses showed unique profiles indicating their different origins. Carried by the Norwegian Atlantic Current (0–800 m) and East Greenland Current (0–300 m), PAH individuals’ net transport mass fluxes ranged from −4.4 ± 1.7 to 53 ± 39 tons year⁻¹ to the Arctic Ocean. We suggested the limited contribution of ocean currents on PAHs’ delivery to the Arctic Ocean, but their role in modulating PAHs’ air–sea interactions and other biogeochemical processes needs further studies.
... Nowadays, as one of the most threatening persistent organic pollutants, polycyclic aromatic hydrocarbons (PAHs) have various properties. For example, they are not degraded easily and long-distance migration enables them to appear anywhere in the world (Zeng et al. 2018;Han et al. 2019;Timoszczuk et al. 2021). As reported by Vodopivez et al. (2021), the presence of PAHs was detected near 25 de Mayo (King George) Island in Antarctica. ...
In order to incorporate the contribution of pollution sources to ecological risks into environmental monitoring, positive matrix factorization-risk quotient (PMF-RQ) was used to quantify the contribution of different PAH sources to ecological risks, which indicated that the unburned petroleum, vehicular emissions, and diesel combustion were the main sources of PAHs in Laizhou Bay and Jiaozhou Bay, and they were caused by petrochemical industry, maritime shipping, and urban traffic exhaust as the major sources of PAHs for ecological risk. Meanwhile, integrated biomarker response (IBR) and multi-biomarker pollution index (MPI) suggested that September was the most polluted month for PAHs in Laizhou Bay and Jiaozhou Bay and the pollution in Laizhou Bay was significantly higher than that in Jiaozhou Bay. This research was dedicated to explore the monitoring pattern for PAH pollution from the source to bioeffects, and it may have contributed a scientific support to monitoring and governance of marine PAH pollution.
... In any case, humans can be directly or indirectly exposed to PAHs through skin contact or seafood consumption. For this reason, research on the PAH pollution of sediments and water and the evaluation of human health risks is of necessity (Zeng et al., 2018). ...
Oil pollution has been one of the most common environmental damages in recent decades, which has been
abundant in oil-producing countries such as Iran. This study aimed at using the artiicial neural network (ANN) to predict the amount of petroleum pollutants including polycyclic aromatic hydrocarbons (PAHs) in the groundwater of the Tehran Oil Reinery by a set of input features, which modeled in MATLAB R2015a. Accordingly, 13 input features were used for developing an ANN model as inputs, including pH values, electrical conductivity, total dissolved solids, and total suspended solids (TDS and TSS), distance from the source of contamination (Distance), the amount of phenol, oil and grease, and the amount of ions such as potassium, sodium, chlorine, sulfate, magnesium, and calcium. The testing and training data for learning the ANN model were produced by applying 45 data obtained from the analyzing of sample wells around the Tehran reinery in the laboratory. Due to the low number of data, back propagation networks were employed for modeling. The regression values for training, validation, and test data were equal to 0.997, 0.991, and 0.917, respectively. Based on the results, the best validation performance was detected in epoch 13. The mean square errors were 0.00348, indicating the high accuracy of the ANN method in the prediction and estimation of PAHs in the mentioned site, and thus this model can be used on sites with similar conditions.
... In this sense, PAHs, the main oil component, represent a global concern due to their environmental persistence, long-range transport, and potential toxic effects, such as carcinogens, mutagens, and teratogens, on humans and animal health. [4][5][6][7] Therefore, monitoring the quality of seafood and water is necessary so that consumption does not become a potential danger to public health. [8] Concerning the occurrence of human activities in the environment, the toxic action of PAHs varies according to their physicochemical properties, where the deposition rate is accelerated both in soil/sediments and in the aquatic environment due to their greater hydrophobicity and low hydrossolubility, very evident characteristics in this class of organic molecules. ...
Polycyclic aromatic hydrocarbons (PAHs), the main component of petroleum, are a concern due to their environmental persistence, long-range transport, and potential toxic effects on animal, human health, and the environment. PAHs are considered persistent compounds and can be bioaccumulated in sediments and aquatic biota. Determining PAHs in animals and environmental samples consists of three steps: extraction, clean-up or purification, and analytical determination. The matrix complexity and the diversity of environmental contaminants, such as PAHs resulted in the development of numerous analytical techniques and protocols for the extraction of these components and analysis in several samples. This systematic review article seeks to relate the extraction and preparation methods of complex samples from aquatic animals and the two main detection techniques of PAHs. For the elaboration of the research, 67 articles published between 2011 and 2021 were sought, which specifically contemplated the isolation of aquatic extracts and detection and quantification techniques of PAHs.
... In any case, humans can be directly or indirectly exposed to PAHs through skin contact or seafood consumption. For this reason, research on the PAH pollution of sediments and water and the evaluation of human health risks is of necessity (Zeng et al., 2018). ...
Oil pollution has been one of the most common environmental damages in recent decades, which has been abundant in oil producing countries such as Iran. This article goal is using the artificial neural network (ANN) for predict the amount of petroleum pollutants (polycyclic aromatic hydrocarbons (PAHs)) in groundwater of the Tehran Oil Refinery by a set of input features, which modelled in MATLAB R2015a. thirteen input features include pH values, electrical conductivity (EC), total suspended solids and soluble solids (TDS, TSS), distance from the source of contamination (Distance) ,the amount of phenol, oil and grease and also the amount of ions such as Potassium (K+), sodium (Na+), chlorine (Cl-), sulfate (So4-) magnesium (Mg2+) and calcium (Ca2+) used for developed ANN model. The testing and training data for learning ANN model were produced using 45 data obtained from experiments. Due to the low number of data, back propagation networks were used for modeling. The results indicate the good performance of the network and show that the ANN model in terms of predictive capability for PAHs pollutant in groundwater is very well.
... ng/L) ( Sarria-Villa et al., 2015 ) and Ovia River, Southern Nigeria ( 17 PAHs = 2.33-25.83 μg/L) ( Tongo et al., 2016 ) and higher than that in Guchenghu Lake ( 16 PAHs = 184-1,160 ng/L) ( Zeng et al., 2018 ), Chaohu Lake, China ( 16 PAHs = 181.5 ng/L) ( Qin et al., 2013 ), and Ganges River, India ( 16 PAHs = 0.05-65.9 ng/L) ( Sharma et al., 2018 ). ...
Nitrated polycyclic aromatic hydrocarbons (NPAHs) are widespread organic pollutants that possess carcinogenic and mutagenic properties, so they may pose a risk to the environment and human health. In this study, the concentrations of 15 NPAHs and 16 polycyclic aromatic hydrocarbons (PAHs) in 30 surface water samples and 26 sediment samples were measured in 2018 from the Taige Canal, one of the main rivers flowing into Taihu Lake, China. The total NPAH concentrations in water and sediment ranged from 14.7 to 235 ng/L and 22.9 to 96.5 ng/g (dw), respectively. 9-nitrophenanthrene (nd–76.3 ng/L) was the dominant compound in surface water, while 2+3-nitrofluoranthene (1.73–18.1 ng/g dw) dominated in sediment. Among PAHs, concentration ranging from 1,097 to 2,981 ng/L and 1,089 to 4,489 ng/g (dw) in surface water and sediment, respectively. There was a strong positive correlation between the log octanol-water partition coefficient (Kow) and log sediment-water partition coefficient due to hydrophobic interaction. The fugacity fraction value increased with the decrease of log Kow, and chrysene was transferred from water into sediment. The residual NPAHs in surface water and sediment of the Taige Canal have partial correlation. Diesel engine and coal combustion emissions were probably the principal sources of NPAHs in surface water and sediment. The results of ecological risk assessment showed that some NPAHs in water (e.g, 1-nitropyrene and 6-nitrochrysene) and sediment (e.g., 2-nitrobiphenyl, 5-nitroacenaphthene, 9-nitrophenanthrene and 2+3-nitrofluoranthene) had moderate ecological risks, which should be of concern.
... Factor 1 made the most significant contribution (46.3%) to the total measured PAHs, was dominated by Phe, Acp, and Flu, and had a load of BaA. This factor was designated as the typical product of wood/ coal combustion and vehicle emission, as Phe, Pyr, and BaA were reported to result from such processes (Stogiannidis and Laane, 2015;Zeng et al., 2018). Factor 2 explained 9.8% of the PAH concentrations, with high loadings of Chr, Ant, and Phe, identified as characteristic PAHs for natural gas combustion (Duodu et al., 2017). ...
In the Indian Ocean, the marine fate of polycyclic aromatic hydrocarbons (PAHs) is impacted by the unique air-sea interactions with great monsoon characters. By collecting water-column samples during the monsoon transition period, we found PAHs (∑8PAH: 1.1–27 ng L⁻¹) showed significantly different distributions from the Bay of Bengal, Equatorial Indian Ocean, Eastern Indian Ocean, and the South China Sea (p < 0.001). Their vertical profiles showed natural logarithm relationships with depth in the Bay of Bengal and Equatorial Indian Ocean. PAHs were mainly from wood/coal combustion and vehicle emission. The estimation of PAHs’ air-seawater exchange flux revealed net volatilizations from seawater except in the Eastern Indian Ocean. The Wyrtki Jet, a surface current driven by the westerly wind, was observed in the equatorial area. This swift current could transport PAHs eastward efficiently with a mass flux of 636 ± 188 g s⁻¹. The subsurface current, Equatorial Undercurrent, played a less crucial role in PAHs’ lateral transport with a flux of 115 ± 31.3 g s⁻¹. This study preliminarily revealed the role of air-sea interactions on PAHs’ transport and fate in the open ocean. The coupled air-sea interactions with biogeochemical processes should be considered in future work.
... The PAHs distribution pattern in the sediments of a water body is usually dominated by high molecular weight (HMW) PAHs (Kanzari et al. 2014;Zeng et al. 2018). However, while conducting several researches in various Lithuanian water bodies, we noticed that low molecular weight (LMW) PAH naphthalene is often found to exceed sediment quality guidelines (TEL) and/or be the prevailing compound in the sediment of lakes and rivers (Stakėnienė et al. 2019). ...
In this study, results on PAHs distribution, origin and ecological risks from several surveys are combined with a special focus on naphthalene. The study area comprises a large part of the Lithuanian territory and includes two biggest Lithuanian rivers, Nemunas and Neris (sampling locations with different hydrodynamics and varying anthropogenic pressure), four different lakes and the central part of the Curonian Lagoon. ∑16PAHs concentrations in the surface sediment ranged between 74.5 and 6377 ng g-1 dw. In 9 locations out of 14, naphthalene concentration exceeded TEL and posed a threat to the environment. Naphthalene was a significant contributor to the total PAHs concentration in the study area with concentrations ranging from 0.78 to 106 ng g-1 dw. Despite the highest naphthalene concentration recorded in Lake Talkša, naphthalene had only a minor contribution to the PAH profile in this lake. Even a lower impact of naphthalene was observed in the Curonian Lagoon. Naphthalene was found to be the prevailing compound in the Nemunas River Delta region, in a relatively clean Lithuanian Lake Dusia and in some Neris River locations. The highest contribution of naphthalene was observed in the areas with low urbanization degree, but close to peatlands. The main naphthalene source in the study area might be related to peatlands, albeit additional naphthalene sources, such as food cooking, burning of agricultural residues, wood and coal could not be completely rejected either. The sources of other PAHs are attributed to the vehicular emission, emissions from industry, biomass and coal burning.
... Responsible Editor: Gangrong Shi are ubiquitous in the atmosphere, soil, and water and are migrated or transferred between them (Tarafdar and Sinha 2018;Zeng et al. 2018). Atmospheric PAHs pollution mainly comes from combustion of coal and biomass, which has been widely concerned in the last two decades. ...
Foliar uptake, as an important pathway of polycyclic aromatic hydrocarbons (PAHs) accumulation in winter wheat, has a great contribution to wheat PAHs, which mainly depends on atmospheric PAHs level. An indoor simulation experiment was conducted to explore the effects of foliar exposure to PAHs at different growth stages on PAHs uptake in wheat. Three levels (0, 0.75, 4.5 mg L⁻¹) of mixed solution of three PAHs (Σ3PAHs) including naphthalene (NAP), phenanthrene (PHE), and benzo(b)fluoranthene (BbF) were sprayed on leaves of two varieties (Yunong, YN; Xiaoyan, XY) of winter wheat (Triticum aestivum L.) during the booting, heading, pre-filling, and post-filling stage. The results showed that the sprayed PAHs exhibited little effects on the growth of the two varieties except the stem biomass of YN was significantly (p < 0.05) reduced when high concentration of PAHs was applied at the post-filling stage. PAHs concentration in winter wheat grain was highest under foliar exposure at the pre-filling stage, while the lowest was found under foliar exposure at the post-filling stage. Transfer factor of PAHs from stem to root (TFroot/stem) of three PAHs when foliar exposure to PAHs at the booting and heading stage was significantly (p < 0.001) higher than that at the pre-filling and post-filling stage, while TFgrain/glume of three PAHs when foliar exposure to PAHs at pre-filling stage was significantly (p < 0.01) higher than that at the other three stages. These results indicated that foliar exposure to PAHs during the vegetative growth stage was transferred and distributed to the root, while PAHs are mainly transferred and accumulated to the grain during the grain filling stage. Additionally, the higher lipophilic PAHs showed a lower ability to transfer from the glume to grain, and larger flag leaf area had the potential to promote the enrichment of PAHs in grain. This study indicated that the health risk of PAHs in winter wheat could be effectively reduced by controlling atmospheric PAHs level during pre-filling stage.
... PAHs can be formed in three ways: Pyrogenic, petrogenic, and biological (10,(18)(19)(20). The persistent sources of PAHs in the environment are anthropogenic, such as ship transit, municipal runoff, petroleum leakage, water, and industrial sewage, which leads to the entry of PAHs into aquatic environments (2,21,22). ...
Background: Polycyclic aromatic hydrocarbons (PAHs) are stable and highly toxic environmental pollutants, which are produced mainly through combustion processes. The present study aimed to identify and determine PAHs compounds and their ecotoxicological effects in surface sediments of 20 stations in Bushehr province (Assaluyeh, Kangan, Khark, Emam Hasan, and Bushehr areas). Methods: All sediment samples (0-5 cm) were collected from 20 sites of Persian Gulf costs (Bushehr province, Iran). The concentration of PAHs was determined by HPLC. Then, in order to identify the sources of PAHs, ƩLPAHs/ƩHPAHs, IP/ (IP+BP), PH/AN, and AN/(PH+AN) ratios were obtained. Sediment quality guidelines (SQGs) and sediment quality criteria (SQC) were used to measure the PAHs ecotoxicological effects in sediments. Results: Based on PAHs isomeric ratios, the contaminants of sediments originated from pyrogenic resources. ƩPAHs values (ng/g dw) in sediment samples ranged from ND to 49180. The toxic equivalent concentration (TEQ car) of PAHs raged from ND-7999 ngTEQ/g. Based on SQGs and SQC, the concentrations of ƩPAHs compounds in 10% and 6% of the sampling stations exceeded effects range median (ERM) and frequent effect level (FEL), respectively, indicating negative ecological risk effects. Conclusion: Sampling stations sediments must be routinely checked for PAHs because may lead to a negative effect on the marine ecosystem, organisms, and humans.
... Devido aos HPAs de origem petrogênica estarem cada vez mais presentes na natureza, diversos pesquisadores vêm estudando os impactos em várias matrizes ambientais e em métodos para recuperar essas áreas de forma sustentável por meio do desenvolvimento de processos e de invenções com potencial de serem utilizadas na biodegradação de petróleo em diferentes ambientes (ZENG et al., 2018, LOFTHUS et al., 2018LI;LIU, 2017). ...
A presente pesquisa tem como objetivo realizar a prospecção do atual cenário tecnológico no uso de fungos e extratos vegetais nos processos de biorremediação de hidrocarbonetos. Para o desenvolvimento dessa prospecção, foram retiradas informações do banco de dados Web of Science – Espacenet, no Registro Europeu de Patentes (EPO), uma plataforma em nível Europeu que contém as principais informações sobre as patentes depositadas. A pesquisa foi feita por meio da utilização de palavras-chave e dos códigos de indexação B09C1/10 – Microbiologicamente, biologicamente ou usando enzimas e C02F2101/32 – Hidrocarbonetos ou petróleo. Como resultado, foram obtidos: a quantidade de patentes depositadas durantes os anos, quais os principais inventores, que empresas têm desenvolvido novas tecnologias e qual a aplicabilidade dessas invenções. Constatou-se que o desenvolvimento biotecnológico voltado para a biorremediação de áreas impactadas por hidrocarbonetos só obteve maior investimento a partir de 2013, tendo maior destaque para o ano de 2016 com 20 invenções depositadas.
This study presents the first data on a 2018–2021 campaign to monitor polycyclic aromatic hydrocarbon levels, PAHs, in the final stretch of the Hooghly River in West Bengal, India. The range of sedimentary PAHs was 0–47,366 ng/g, higher than the ranges given by the literature for comparable study areas. The assay reveals an outstanding level of PAHs contamination in the fine sediments of the Hooghly River and Sundarban wetland, where the dominance of 4–6 ring PAHs was 83% of the total. The diagnostic ratios based on molecular ratios of PAHs show that the pollution comes mainly from the combustion of petroleum. The ratio of anthracene relative to anthracene plus phenanthrene, ANT/(ANT + PHE), was >0.30, which is higher than the reference discriminant ratio of >0.10, suggesting that PAHs were from the combustion source. In the meantime, fluoranthene over the sum of fluoranthene plus pyrene, FLT/(FLT + PYR), was >0.5 and indicated coal combustion, in agreement with the literature. The mean level of carcinogenic hydrocarbons was at 18% of the total measured PAH, with a peak of 91%, revealing significant potential risk for humans and ecosystems. The toxicity equivalence factors, TEF, of the individual PAHs and the total BaP equivalent toxicity, TEQ, were adopted as a comparison reference of sediment quality. At most sites, toxic effect ranges were classified as high and very high. The results of this research call for public authorities to remedy a situation of severe ecological risk.
Worldwide, studies on polycyclic aromatic hydrocarbons (PAHs) especially focusing on fishing harbours have been found in a limited magnitude only. The characteristics of 16 PAHs and their associated ecological adversities in different environmental compartments of Veraval fishing harbour have been investigated. The concentrations of total PAHs in dissolved, particulate and sediment phases varied from 358.19–42,712 ng L⁻¹, 1450.83–15,291.60 ng g⁻¹ dw and 1263.53–217,560.30 ng g⁻¹ dw, respectively. Two approaches adopted for the source apportionment of PAHs, molecular diagnostic ratio (MDR) method and principal component analysis (PCA), implied the impact of potential anthropogenic PAH sources, including petroleum leakage, pollution from boat repairing, maintenance and burning of coal emissions. The interpretation and integration of indices such as the total toxicity equivalence (TEQcarc), mean risk quotient (M-RQ) and mean effect range-medium quotient (M-ERM-Q) indicated that the harbour areas were under severe threat of ecological risk due to the highest concentration of PAHs, while the offshore region signified a high or moderate level of risk. The present study provides effectual scientific insight into the role of fishing harbours in PAH pollution.
Graphical Abstract
The Fundão dam failure in 2015 severely impaired the economy, the lives of riverine communities and the aquatic ecosystems of the Rio Doce basin in SE Brazil. Several contaminants, including polycyclic aromatic hydrocarbons (PAHs), were transported downstream, deposited on the estuary, and released into the Atlantic Ocean. The high concentration of PAHs in estuarine sediments may offer ecological risks and deleterious effects to benthic organisms, so here we aimed to determine the source and fate of these compounds before and after the tailing's arrival. The mean concentration of the analyzed Σ16PAHs increased from 34.05 µg kg-1 in the pre-failure period to 751.77 µg kg-1 one year after the arrival of the tailing. The classification of the sediment quality changed from low to moderate contamination. Our results suggest that there was PAHs remobilization by mine tailings along the Rio Doce basin. The target analytes showed mostly a pyrolytic profile from fossil fuel and biomass burning. In addition to other contaminants deposited in the estuary after the arrival of the tailings, this study showed that the profile change of PAHs in the estuary region is a consequence of the mud's erosive power.
This study systematically analysed the distribution characteristics, sources and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in Kuye River sediments in an energy and chemical industry base in northern Shaanxi, China. The results revealed the concentrations of 16 PAHs in the sediment ranged from 1090.04 to 32175.68 ng∙g − 1 dw, with the highest proportion of 4-rings PAHs; PMF revealed the main sources of PAHs were the incomplete combustion of fossil fuel, biomass combustion and traffic emissions. The total toxic equivalent concentration of BaP, risk quotient and life time carcinogenic risk of PAHs suggested the moderate to high contamination of PAHs. The higher ILCR indicated the ingestion of PAHs was the main way to impact public health, and children should be more susceptible to PAHs. This study could provide theoretical support for pollution prevention measures and ecological restoration strategies for rivers in energy and chemical areas.
Historical trends of polycyclic aromatic hydrocarbons (PAHs) contamination were reconstructed from eleven sediment cores located in intertidal zones of the Yellow and Bohai seas for a period encompassing the last 80 years. The analysis encompassed 15 traditional PAHs (t-PAHs), 9 emerging PAHs (e-PAHs), and 30 halogenated PAHs (Hl-PAHs), including 10 chlorinated PAHs (Cl-PAHs) and 20 brominated PAHs (Br-PAHs). Concentrations of target PAHs were highest in industrial and municipal areas situated along the coast of the Bohai Sea, including Huludao, Yingkou, Tianjin, and Dandong, constituting a substantial mass inventory. All target PAHs showed increasing trends since the 1950s, reflecting the development history of South Korea and China. High molecular weight PAHs accumulated in sampling sites more than low molecular weight PAHs. A positive matrix factorization model showed that the PAH sources were coal and gasoline combustion (35%), diesel combustion (33%), and biomass combustion (32%). Over the last 80 years, the contribution of coal and gasoline combustion increased in all regions, while diesel combustion and biomass combustion varied across regions and over time. Toxicity equivalence values were highest for t-PAHs (>99% contribution), followed by Cl-PAHs, Br-PAHs, and e-PAHs. Concentrations of t-PAHs in Eastern Asia seas have increased since the 1900s, particularly in intertidal areas compared to subtidal areas. The intertidal zone removed 83% of the total flux of PAHs originating from land and thus appears to serve as a buffer zone against marine pollution. Overall, this study provides novel knowledge on the historical trends and sources of PAHs on a large scale, along with insights for future coastal management.
The US Environmental Protection Agency (US-EPA) published a priority list of 16 polycyclic aromatic hydrocarbons (PAHs), which are compounds that are studied in a variety of matrices due to their wide range of risks. Environmental compartments can be contaminated with PAHs from different sources, such as wastewater from industries and petroleum spills. For the case of Cameroon, there are no recorded data concerning the sources, distributions, and toxicity levels of PAHs in water and sediment from Cameroon beaches which are found in South-West, Littoral, and South Regions. In this work, only three beaches from South-West Region were studied regarding the sources, distributions, and toxicity levels of PAHs in water and sediment. The analyzed samples came from Bobende coastal beach, Down-beach, and Cape-Limboh beach. To achieve the analyses, liquid–liquid extraction and gas chromatography enabled the identification and quantification of PAH compounds from sediments and marine water. Out of the 16 PAHs listed by US-EPA, twelve were identified and quantified among which four of them were light molecular weight PAHs (acenaphthylene, fluorene, phenanthrene, and anthracene). Anthracene in the Cape-Limboh sample presented the highest concentration (477.57 ng/kg weight of dry sediment) of LMW-PAHs. Eight identified and quantified PAHs of high molecular weight as a whole, three absent PAHs (benzo[a]anthracene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene) in the Cape-Limboh sample, while only one is absent in the Bobende samples (dibenzo[a,h]anthracene) and Down Beach (benzo[g,h,i]perylene). According to the ratios used for the determination of the sources of PAHs, it came out that the source of PAHs from all beaches is pyrolytic. In all samples, BaA is the only high molecular weight PAH presenting serious toxicity and ecological risk.
The incorporation of plasmonic metals into semiconductors forming heterojunction photocatalysts is a promising route to enhance the photocatalytic performance in visible light. In this work, we reported the visible-light-driven one-dimensional (1D) nanostick silver/silver sulfide (Ag/Ag2S) photocatalyst combining with two-dimensional (2D) nanosheet reduced graphene oxide intersected by hollow structure (h-RGO) was prepared via a feasible approach at room temperature. The density of Ag depositing on the surface of Ag2S was easily tuned by the concentration of sodium borohydride and the silicon dioxide nanospheres were employed as templates in the preparation of h-RGO by the layer-by-layer (LBL) assembly. The ternary plasmonic Ag/Ag2S/h-RGO photocatalysts exhibited better photocatalytic performance for degradation of naphthalene (95.95%) and 1-naphthol (98.65%) under visible light than the pure Ag2S, composite Ag/Ag2S and composite Ag/Ag2S/RGO. Localized surface plasmon resonance of Ag, heterojunction formed between Ag/Ag2S and RGO and the unique characteristics of h-RGO, which included higher specific surface areas, more efficient reflections of light and more active sites than RGO for boosting separation efficiency of charge carriers, were all responsible for such enhancement. By combining the characterization results with various computations, the mechanism, potential degradation pathways and the toxicity of the generated intermediates for photodegradation were examined. In addition to offering profound insight into the expansion of effective plasmonic photocatalysts with novel structures, the current study is beneficial to ease the environmental crisis to a certain extent.
Polycyclic aromatic hydrocarbons (PAHs) have gathered worldwide attention due to their carcinogenicity and toxicity. This paper aims to review and extend current knowledge on PAHs in aquatic environments in Turkey, where expansion of the marine industry has caused contamination concerns. To assess cancer and ecological risks associated with PAHs, we systematically reviewed 39 research articles. Mean measured concentrations of total PAHs ranged from 61 to 249,900 ng L-1 in surface waters, 1 to 209,400 ng g-1 in sediments, and 4 to 55,000 ng g-1 in organisms. Estimated cancer risks from concentrations in organisms were higher than those from surface waters and sediments. Negative ecosystem impacts of petrogenic PAHs were estimated to be larger than those of pyrogenic origin, despite the predominance of the latter. Overall, the Marmara, Aegean, and Black seas are highly-polluted and need remedial action, while further study is needed to confirm the status of other water bodies.
Rivers and their reservoirs form a connected river-reservoir system that plays an important role in regulating the water environment. However, the distribution and potential environmental behaviour of polycyclic aromatic hydrocarbons (PAHs) in the river-reservoir system are scarce. This study focused on the occurrence, distribution and risk assessment of PAHs in a river-reservoir system based in the Dongjiang river source area. The concentration of Σ 16 PAHs in the water phase of the river-reservoir system was 102.2-407.6 ng/L and at a low level, with the main monomer being naphthalene (Nap). The main pollution source was dominated by a mixture of charcoal, coal and gasoline combustion. The proportion of gasoline and diesel combustion in the reservoir system was higher than the river system. In contrast, the occurrence level of Σ 16 PAHs in the reservoir system was relatively higher than the river. On the time scale, the levels of Nap were greatly enhanced in the spring, which might be correlated with its abundant input of stormwater runoff. The composition of the PAHs remained stable during the transition from river to reservoir, suggesting their durability and stability in the aquatic environment. Redundancy analysis indicated that temperature, NO 3 ⁻ , and NH 4 ⁺ could impact the PAHs content. In general, the environmental risk of PAHs in the aqueous phase was at moderate risk and low health risk, with no effect on the safety of drinking water.
In the water environment such as lakes, there is a phenomenon that the sediment and overlying water are polluted at the same time. In this study, A microbial electrochemical system with an embedded active electrode was developed for simultaneous removal of polycyclic aromatic hydrocarbons in sediment and antibiotics in overlying water by in-situ utilization of electrons. In the closed-circuit group, the pyrene concentration in sediment decreased from 9.94 to 2.08 mg/L in 96 d, and the sulfamethoxazole concentration in water decreased from 5.12 to 1.12 mg/L in 168 h. These values were 18.71% and 31.21% higher, respectively, than those of the open-circuit group. The pyrene degradation pathway may be from polycyclic aromatic substances to low-cyclic aromatic hydrocarbons via successive breakdown of benzene rings. Multiple metabolites produced by reduction verified that SMX or its intermediates were reductively degraded in water. On the active electrode, the relative abundances of Acetobacterium and Piscinibacter, which were genera related to SMX degradation, was promoted, while the electricity-producing genus Pseudomonas was inhibited. ccdA, pksS, torC, and acsE genes related to extracellular electron transport may accelerate electron transport. Electrons could be transferred to SMX under the influence of proteins involved in extracellular electron transport, and SMX could be degraded reductively as an electron acceptor by microbes. Generation of electrons and in-situ utilization for simultaneous removal of solid-liquid two-phase pollutants will provide mechanistic insight into pollutant biodegradation by microbial electrochemistry and promote the development of sustainable bioremediation strategies for surface water.
As one of the emerging contaminants, polycyclic aromatic hydrocarbons (PAHs) were ubiquitous in the environment and bioaccumulation characteristics, posed a potential risk to the environment and human health. In this study, four types of bricks including red clay bricks, gray clay bricks, lime–sand bricks and cinder bricks were used for the removal of PAHs phenanthrene and pyrene from aqueous solution. Each type of brick was systematically characterized. Adsorption of phenanthrene and pyrene could be well described by Langmuir model and pseudo-second-order kinetics model. Results showed that the adsorption rate of phenanthrene and pyrene follows different order attributes to the difference in the molecule size of PAHs and the physical properties of bricks. The maximum adsorption capacities of red clay bricks, cinder bricks lime, lime–sand bricks and gray clay bricks for phenanthrene and pyrene were 290.58, 85.97, 53.47 and 36.55 μg g−1 and 42.56, 26.82, 15.31 and 11.90 μg g−1, respectively. Iron oxides could enhance the adsorption capacity of phenanthrene onto waste bricks within a certain range, while they have little effect on the adsorption capacity of pyrene. The four types of bricks were used for the removal of PAHs from NaCl solution (0.001–0.1 M). The adsorption capacity of phenanthrene and pyrene was found to increase slightly and then decrease for each type of brick due to the specific adsorption site and the salting-out effect. The present study provides evidence that waste bricks as economical and abundant materials have great potential adsorption effect on PAHs from water environment.Graphical abstract
The 2013 “Qingdao oil pipeline explosion” contaminated about 2.5 km of shoreline in the Jiaozhou Bay area and aroused widespread concern because of the serious casualties even though it was not the most severe oil-spill contamination in China. To evaluate the long-term impact, we collected thirty-three surface sediment samples after 3 years of the accident, with sixteen polycyclic aromatic hydrocarbons (PAHs) detected. Spatial-temporal variation in PAHs revealed that a minimal impact might still be present after 3 years. Source analysis combined with a one-way ANOVA showed that pyrolytic sources were consistently predominant. The environmental impact was already minimal 3 years later and negligible thereafter. Although the cancer risk has decreased over the years, there has always been a potential hazard to human for specific occupation, with all of the risk values exceeded 10⁻⁶. This study offers a reference for assessing the long-term impact of oil spills in similar bay areas.
Polycyclic aromatic hydrocarbons (PAHs) are one of the most frequent petroleum hydrocarbons detected in the environment. PAHs are receiving global attention due to their toxicity, environmental persistence, and potential bioaccumulation. PAHs contamination occurs mainly due to anthropogenic sources related to the disposal of industrial and domestic run-offs or atmospheric emissions from plants or vehicles. Once PAHs are introduced into the environment, they undergo different processes either physical, chemical, or biological transformations, which are collectively known as weathering processes. These weathering processes are highly dependent on the nature and the physiochemical properties of PAHs molecules and the surrounding environment, which eventually will determine their transport, fate, and distribution in the environment either through adsorption to soil/sediments, or volatilization to the atmosphere, or dissolution in the water. Different treatment strategies for PAHs pollution have been introduced. Each remediation technology has its advantages and disadvantages. To choose a treatment, a full analysis of the case study should be provided, including the properties of the target pollutant, site description, and treatment procedure. As the treatment of PAHs contaminated sites is usually a difficult and expensive task, it would be a good choice to go for treatment, which is adaptive, sustainable, eco-friendly, efficient, and cost-effective. In this review, the transport, fate, and distribution processes of PAHs in the environment with their dependent factors were elaborated. In addition, this paper provided an overview of different traditional and advanced potential treatment approaches used to treat PAHs-contaminated sites such as thermal, chemical, electrokinetic, nano-adsorption, and biological treatments.
This study constructed sediment microbial fuel cells (SMFCs) for polycyclic aromatic hydrocarbons (PAHs) removal in contaminated aquaculture sediment. Starch, a waste deposited in aquaculture sediment, was employed as the co-substrate for electricity generation and PAHs removal, and the effect of starch-derived organic acids on SMFC performance was assessed. The results indicated that sufficient starch promoted PAHs removal (69.9% for naphthalene, 55.6% for acenaphthene, and 46.8% for pyrene) in dual-chamber SMFC, whereas excessive starch attenuated SMFC performance because the organic acids accumulation reduced anode pH, decreased species diversity, and changed the microbial communities. The electricity generation and PAHs removal were positively correlated (R > 0.96), and both of them were related to Macellibacteroides belonging to Bacteroidetes. However, a larger single-chamber SMFC device did not obtain enhanced PAHs removal owing to the restricted “effective range” of the anode. Hence, more challenges need to be addressed to realize the practical application of SMFC.
This study aimed to investigate characteristics of Polycyclic Aromatic Hydrocarbons in Changdang Lake, China during March (dry season), June (wet season) and September (Moderate Season). The average concentration of polycyclic aromatic hydrocarbons in March averaged 100.08ng /L (35.31~200.38ng/L), June 154.72ng/L (100.80~218.74ng/L), and in September 93.77ng/L (66.75~106.41ng/L). Among them, the residual benzo(a)pyrene was 5.90ng/L in water. By applying the redundancy analysis, results showed higher correlation between the fraction of 10-100kDa organic matter and the residues of higher rings PAHs (BbF, BkF, DahA, Bghip) and middle-rings PAHs (Ace and Chr). According to the risk classification of individual PAHs in water, the eco-toxicological risks of Ace, BaA, BbF, BaP and BkF in March, the Nap, Ace, Flu, Phe, Ant and BaA in June and Nap, Ace, Flu, Phe, Ant, BaA and BbF in September had reached moderate risk level. The lowest toxicological risk of PAHS in the Lake was found at site 2#and 3#, located near the center of the Lake. This study results also revealed that combine treatment processes of activated carbon and ultra-filtration membrane were quite efficient in removing PAHs from the water of Changdang Lake. Results obtained from this study meets the requirements of "drinking water health standards" (GB5749-2006) (PAHs <2000ng/L), However continuous monitoring and necessary actions are required to ensure the availability of safe water to the human and other living organism.
PAHs are organic pollutants that have carcinogenic and mutagenic impacts on human health and are a subject of great concern. The soil-bound polycyclic aromatic hydrocarbons (PAHs) in the urban areas can be very lethal to human health. The concentrations, sources, and possible cancer risks of 15 PAHs were analysed by collecting roadside soil samples in Lucknow, India. The range of ∑15PAHs was found to be 478.94 ng/g to 8164.07 ng/g with a mean concentration of 3748.23 ng/g. The highest contribution (32.5%) was found to be from four-ring PAHs, followed by six-ring (24.5%) and five-ring (16.7%) PAHs. The source apportionment through diagnostic ratios ANT/(ANT + PHE) against FL-2/(FL-2+PYR) highlighted the dominance of petroleum, wood, coal, and grass combustion as sources of PAHs in the study area. Source apportionment was also done through positive matrix factorization, confirming the dominance of ‘vehicular emissions’ (49%), followed by ‘coal and biomass combustion’ (∼39%), and ‘leakages, volatilization and petroleum combustion’ (∼12%) as potential sources. The results from lifetime cancer risks (ILCR) varied in the range of 7.5 × 10⁻⁴ and 1.3 × 10 × ⁻² illustrating ‘high cancer risk’. The total cancer risk susceptibility of children was found to be 31% more than that of adults. The highest risk associated with toxic equivalent concentration (TEQ) was found at site S8 highlighting the impact of the presence of an international airport, and huge traffic load. The present study will prove to be useful for information related to human exposure to PAHs content in soil in the study area and as baseline study for policy makers, stakeholders, and researchers.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants generated primarily during the incomplete combustion of organic materials (e.g. coal, oil, petrol, and wood). Emissions from anthropogenic activities predominate; nevertheless, some PAHs in the environment originate from natural sources such as open burning, natural losses or seeps of petroleum or coal deposits, and volcanic activities. Major anthropogenic sources of PAHs include residential heating, coal gasification and liquefying plants, carbon black, coal-tar pitch and asphalt production, coke and aluminum production, catalytic cracking towers and related activities in petroleum refineries as well as and motor vehicle exhaust. PAHs are found in the ambient air in gas-phase and as sorbet to aerosols. Atmospheric partitioning of PAH compounds between the particulate and the gaseous phases strongly influences their fate and transport in the atmosphere and the way they enter into human body. The removal of PAHs from the atmosphere by dry and wet deposition processes are strongly influenced by their gas/particle partitioning. Atmospheric deposition is a major source for PAHs in soil.
Many PAHs have toxic, mutagenic and/or carcinogenic properties. PAHs are highly lipid soluble and thus readily absorbed from the gastrointestinal tract of mammals. They are rapidly distributed in a wide variety of tissues with a marked tendency for localization in body fat. Metabolism of PAHs occurs via the cytochrome P450-mediated mixed function oxidase system with oxidation or hydroxylation as the first step.
Several different remediation technologies have been tested in efforts to remove these environmental contaminants. Among them, bioremediation is showing particular promise as a safe and cost-effective option. In spite of their xenobiotic properties, a variety of genera of gram-positive and -negative bacteria, fungi and algae have been isolated and characterized for their ability to utilize PAHs.
The aim of this review is to discuss PAHs impact on the environmental and the magnitude of the human health risks posed by such substances. Also contain important information on the concentrations, burdens and fate of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. The main anthropogenic sources of PAHs and their effect on the concentrations of these compounds in air are discussed. The fate of PAHs in the air, their persistence and the main mechanisms of their losses are presented. Health hazards associated with PAH air pollution is stressed.
Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) used in agricultural, industrial, and domestic applications are widely distributed and bioaccumulate in food webs, causing adverse effects to the biosphere. A review of published data for 1977–2015 for a wide range of vegetation around the globe indicates an extensive load of pollutants in vegetation. On a global perspective, the accumulation of POPs and PAHs in vegetation depends on the industrialization history across continents and distance to emission sources, beyond organism type and climatic variables. International regulations initially reduced the concentrations of POPs in vegetation in rural areas, but concentrations of HCB, HCHs, and DDTs at remote sites did not decrease or even increased over time, pointing to a remobilization of POPs from source areas to remote sites. The concentrations of compounds currently in use, PBDEs and PAHs, are still increasing in vegetation. Differential congener specific accumulation is mostly determined by continent—in accordance to the different regulations of HCHs, PCBs and PBDEs in different countries—and by plant type (PAHs). These results support a concerning general accumulation of toxic pollutants in most ecosystems of the globe that for some compounds is still far from being mitigated in the near future.
To investigate the distributions, degree, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in bed sediments from four rivers of Xinxiang, 18 sediment samples were analyzed. The concentrations ranged from 4.45 × 103 to 29.0 × 103 ng/g for ∑15PAHs (sum of US Environmental Protection Agency (EPA) priority PAHs apart from naphthalene (Nap)) and 3.37 × 103 to 23.5 × 103 ng/g for ∑7carPAHs (including benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DBA), and indeno[1,2,3-cd]pyrene (InP)) with average concentrations of 10.7 × 103 and 7.99 × 103 ng/g, respectively. Compared with those from other rivers in China, sediments from four rivers of Xinxiang were severely polluted with PAHs. Pearson correlation analysis showed that ∑15PAHs concentrations had a significant positive correlation with black carbon content. Four- to six-ring PAHs accounted for 83.4 % of total PAHs, which indicated that the main source of PAHs in the studied area could be pyrogenic contamination. Source apportionment using PCA/MLR and UNMIX revealed that coal and biomass combustion contributed 64.4–67.1 %, gasoline vehicle 23.2–27.2 %, and diesel vehicle 5.70–12.4 % of the total PAHs, respectively. The effects range low/effects range median (ERL/ERM) values showed that there was a high level of toxicity risk for BaA. The ecological risk assessment by mean effects range median quotients (mERMQ) revealed a medium ecological risk of ∑15PAHs in sediments from four rivers of Xinxiang, manifesting that a close attention should be paid to pollution of PAHs in the studied area.
The Polycyclic Aromatic Hydrocarbons (PAHs or polyaromatic hydrocarbons) have been extensively studied to understand their distribution, fate and effects in the environment (Haftka 2009; Laane et al. 1999, 2006, 2013; Okuda et al. 2002; Page et al. 1999; Pavlova and Ivanova 2003; Stout et al. 2001a; Zhang et al. 2005). They are organic compounds consisting of conjoined aromatic rings without heteroatoms (Schwarzenbach et al. 2003). Sander and Wise (1997) list 660 parent PAH compounds (i.e., aromatic substances without alkyl groups and consisting solely of fused rings connected to each other), ranging from the monocyclic molecule of benzene (molecular weight = 78) up to nine-ringed structures (MW up to 478). PAHs containing one or more alkyl groups are called alkyl PAHs. Our study deals with the parent compounds (without alkyl groups and/or heteroatoms), the alkyl PAHs (denoted as PAHn, with n referring to the number of methyl groups; see footnotes in Table 1), and certain heterocyclic sulfur PAHs (dibenzothiophenes). The term PAHs includes all the above, unless explicitly specified. In Table 1, we present the nomenclature of PAHs used in this paper.
Surface soils from a 19 km2 area in east London, UK were analysed for polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) (n=76). ∑16 PAH ranged from 4 to 67 mg/kg (mean 18 mg/kg) and ∑50 PAH ranged from 6 to 88 mg/kg (mean, 25 mg/kg). ∑7 PCB ranged from 1 to 750 μg/kg (mean, 22 μg/kg) and ∑tri-hepta PCB ranged 9 to 2,600 μg/kg (mean, 120 μg/kg). Compared to other international cities concentrations were similar for PAH but higher for PCB. Normal background concentrations (NBC) were calculated and compared to risk-based human health generic assessment criteria (GAC). Benzo[a]pyrene NBC for urban (6.9 mg/kg), semi-urban (4.4 mg/kg) and urban+semi urban (6 mg/kg) domains exceed residential (1 mg/kg) and allotment (2.2 mg/kg) LQM/ CIEH GAC (at 6% SOM) and the Indeno[1,2,3-cd]pyrene NBC for urban (6.8 mg/kg) and urban+semi-urban (5.2 mg/kg) domains exceed the residential (4.2 mg/kg) LQM/CIEH GAC (at 6% SOM).
Capsule Abstract
Normal background concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls are elevated in east London soils in some cases exceed regulatory assessment criteria.
The weight-of-evidence approach to the development of sediment quality guidelines (SQGs) was modified to support the derivation of biological effects-based SQGs for Florida coastal waters. Numerical SQGs were derived for 34 substances, including nine trace metals, 13 individual polycyclic aromatic hydrocarbons (PAHs), three groups of PAHs, total polychlorinated biphenyls (PCBs), seven pesticides and one phthalate ester. For each substance, a threshold effects level (TEL) and a probable effects level (PEL) was calculated. These two values defined three ranges of chemical concentrations, including those that were (1) rarely, (2) occasionally or (3) frequently associated with adverse effects. The SQGs were then evaluated to determine their degree of agreement with other guidelines (an indicator of comparability) and the percent incidence of adverse effects within each concentration range (an indicator of reliability). The guidelines also were used to classify (using a dichotomous system: toxic, with one or more exceedances of the PELs or non-toxic, with no exceedances of the TELs) sediment samples collected from various locations in Florida and the Gulf of Mexico. The accuracy of these predictions was then evaluated using the results of the biological tests that were performed on the same sediment samples. The resultant SQGs were demonstrated to provide practical, reliable and predictive tools for assessing sediment quality in Florida and elsewhere in the southeastern portion of the United States.
Matching biological and chemical data were compiled from numerous modeling, laboratory, and field studies performed in marine
and estuarine sediments. Using these data, two guideline values (an effects range-low and an effects range-median) were determined
for nine trace metals, total PCBs, two pesticides, 13 polynuclear aromatic hydrocarbons (PAHs), and three classes of PAHs.
The two values defined concentration ranges that were: (1) rarely, (2) occasionally, or (3) frequently associated with adverse
effects. The values generally agreed within a factor of 3 or less with those developed with the same methods applied to other
data and to those developed with other effects-based methods. The incidence of adverse effects was quantified within each
of the three concentration ranges as the number of cases in which effects were observed divided by the total number of observations.
The incidence of effects increased markedly with increasing concentrations of all of the individual PAHs, the three classes
of PAHs, and most of the trace metals. Relatively poor relationships were observed between the incidence of effects and the
concentrations of mercury, nickel, total PCB, total DDT and p,p′-DDE. Based upon this evaluation, the approach provided reliable
guidelines for use in sediment quality assessments. This method is being used as a basis for developing National sediment
quality guidelines for Canada and informal, sediment quality guidelines for Florida.
Parent and alkyl PAHs (51 compounds and alkyl homologues) have been quantified in suspended particulates and sediments (345 samples) from the Fraser River system, British Columbia, Canada. The best potential to distinguish natural and anthropogenic sources is exhibited by ratios of the principal mass 178, 202, 228 and 276 parent PAHs, 1,7/2,6+1,7-DMP (dimethylphenanthrene), the phenanthrene/anthracene and fluoranthene/pyrene alkyl PAH series and several less commonly applied PAHs (e.g. acephenanthrylene and pentaphene). Using these ratios we infer sources of PAH to the Fraser basin and evaluate the consistency of these source assignments and the suitability of various commonly applied PAH ratios as indicators. PAH ratios and total concentration data reveal a basin lightly impacted by a variety of sources in its remote regions, especially near roads, but heavily impacted in urban areas, particularly near Vancouver. Contamination sources shift from biomass (e.g. wood and grass) burning to vehicle emissions between remote and urban locations. Stormwater and wastewater discharges appear to collect PAH from urban areas and release them as point sources. In contaminated areas ratios are specific for combustion vs. petroleum sources, and some ratios (202 and 276) distinguish biomass or coal from liquid fossil fuel combustion. At lower concentrations multiple sources at times make interpretations based on a single ratio misleading and the higher mass ratios (228 and 276) may be most applicable to urban areas. In all cases the examination of a variety of PAH indicator ratios that encompass a range of masses is necessary for a robust interpretation.
Bogota is the largest city in Colombia and is considered one of the most ones polluted in Latin America. The annual average PM10 concentration in the city is 55 μg/m3, being as high as 90 μg/m3 in the western region of the city. In this study, two sites in the western region were selected to assess the PM10 contribution from different sources. Two sets of fifty five 24–hour PM10 samples were taken at each site on quartz and Teflon filters. Chemical analysis of these samples was conducted to determine the ion, metal, and organic and elemental carbon concentrations. Ionic balance and mass closure were performed to check the consistency of chemical analysis. Positive Matrix Factorization (PMF) was then applied to determine the source contributions. Mobile sources and fugitive windblown dust were found to be the most significant sources of PM10 at both sites. An ion factor and a secondary aerosol source factor were identified at one site, whereas industry–related factors were identified at the other site, as expected in an area with a high density of small and medium industrial facilities. While it is true that source apportionment studies have been conducted worldwide, this is the first time that the Positive Matrix Factorization (PMF) model is applied in Bogota using full PM10 chemical speciation data, including carbonaceous materials, metals and ions. It is also the first time that a receptor model is applied simultaneously in two sites of the city. We aim that the results from this study will support environmental authorities in designing effective air pollution abatement measures in the city.
Fifteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in two fractions (< 63 μm and 63–850 μm) of street dust samples collected in different urban areas of Rio de Janeiro and Niterói cities, Brazil. Individual PAH concentrations and total PAH concentrations (∑ PAH) were evaluated considering geographic and particle size distributions, PAH source and cancer risk. In 53% of the samples, ∑ PAH values were higher in the smallest particles than in the largest ones, whereas the inverse was true for 23.5% of the samples. In 23.5% of the samples, both classes of particles showed comparable ∑ PAH. The highest ∑ PAH concentrations were found in areas of limited air dispersion, resulting in PAH accumulation in street dust. The diagnostic ratios and principal component analysis (PCA) indicated a strong influence of pyrogenic sources on PAH concentration, mainly of vehicular emissions. The cancer risk levels for children and adults, for both particulate size fractions (< 63 μm and 63 μm–850 μm), were comparable for dermal contact and by ingestion, and ranged from 10− 8 to 10− 6, whereas in certain cases the cancer risk level for adults by dermal contact was 2 to 3 times larger than for children. The cancer risk levels via inhalation always ranged from 10− 13 to 10− 10, so this exposure pathway was almost 10⁴ less severe than through ingestion and dermal contact, and thus negligible.
The present study evaluated the origin and distribution of polycyclic aromatic hydrocarbons (PAHs) and the organic matter (OM) in the surface sediment of the São Paulo River estuary, Todos os Santos Bay (TSB), Brazil. The samples were collected in the rainy (CP1) and the dry (CP2) seasons. We analyzed the 16 PAHs from the United States Environmental Protection Agency (US EPA) priority pollutant list, total organic carbon (TOC), total nitrogen (N), and stable carbon isotope (δ¹³C). The total concentration of PAHs ranged from 11.45 ± 1.28 to 1825.35 ± 107.96 ng g− 1, while TOC ranged from 3.8 to 27.7 g kg− 1. CP1 showed the highest concentrations for all parameters. The δ¹³C ratio indicated terrigenous OM (− 23.81 to − 26.63‰). The TOC/N ratio (C/N) indicated transitional OM (12.32 to 24.39), in addition to the continental origin. The diagnostic ratios of PAHs origin revealed only pyrolytic source, although close to areas with a history of petroleum contamination.
We report levels of polycyclic aromatic hydrocarbons in sediment, seawater, fish and crab samples from Thane creek, India. Concentrations of sixteen USEPA PAH in sediments varies from 874 to 1925 ng g−1, dry weight (dw) in winter, between 219 to 495 ng g−1 in summer. In seawater Σ16 PAHs concentration during winter was recorded 706 ± 193 ng L−1, and during summer 337 ± 79 ng L−1. Total concentrations of PAHs in consumable portion of lizard fish, bombay duck and crab were found 156.8 ± 18 and 122 ± 24.5 ng g−1, 117.4 ± 17.65 ng g−1 and 95.8 ±16.2 ng g−1, 348 ± 94.5 and 95.62 ± 31.9 ng g−1 wet weight (ww) in summer and winter respectively. PAHs concentration were compared with sediments quality guidelines viz. ERL-ERM, TEL-PEL indexes for finding ecotoxicological risk on marine organism. The ILCR values were above public screening criteria for carcinogens.
Polycyclic aromatic hydrocarbons (PAHs) are mainly produced by combustion processes and consist of a number of toxic compounds. They are always emitted as a mixture and have become a major type of pollutants in urban areas. The degree of soil contamination by PAHs is of special concern in areas immediately in proximity to cities with heavy traffic, factories, older buildings, and infrastructure. The accumulation of soil PAHs is also affected by non–anthropogenic factors, such as climate, vegetation, and soil property. This paper reviews three typical source identification techniques, including diagnostic ratios, positive matrix factorization, and principle components analysis. The advantages or disadvantages of these techniques are analyzed. It is recommended that multiple identification techniques be used to determine the sources in order to minimize the weaknesses inherent in each method and thereby to strengthen the conclusions for PAH source identification.
The concentration and distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in surface water, sediment, and fish (Clarias gariepinus) samples collected from Ovia River, Southern Nigeria were evaluated, to assess the contamination profile of the river. The concentrations of PAHs were measured to reflect the spatial and monthly distribution of PAHs in the matrices. Mean concentrations of total PAHs (∑PAHs) in surface water samples ranged from 2.33 to 25.83 μg/L sediment, 5.25 to 573.33 μg/kg-dry weight (dw) and fish (Clarias gariepinus), 10 to 914.17 μg/kg-wet weight (ww). There was a considerable predominance of the 2 and 3-rings PAHs in all the matrices. Spatial variations showed high concentrations of PAHs in Ekenwan, the downstream station, for all the matrices. The ratios of specific PAHs compounds in sediment reflected the predominance of petrogenic PAHs sources. PAH concentrations in water were observed to be above the guideline value (0.05 μg/L) for PAHs in drinking water which calls for serious pollution concern, as this river serves as drinking water source for people of the community.
Sediment samples collected over a 3-year period from Brisbane River, Australia, were analysed for fifteen (15) polycyclic aromatic hydrocarbons (PAHs). The total PAH concentrations varied from 148 to 3079 ng/g with a mean concentration of 849 ± 646 ng/g. The study revealed that PAH input into the river was primarily dominated by pyrogenic sources as evidenced by the predominance of the high molecular weight (HMW) PAHs. Temporal variations of PAHs can be linked to the level of urbanization, with continuous input of combustion related PAHs in the commercial area of the river. Inherent deficiencies in using a single source identification/apportionment approach were overcome by using diagnostic ratios, principal component analysis/absolute principal component scores (PCA/APCS) and positive matrix factorization (PMF). Both, PCA/APCS and PMF resolved four (4) identical factors or sources of PAHs, namely: gasoline emissions, diesel emissions, biomass burning and natural gas combustion. Diagnostic ratios, PCA/APCS and PMF analysis indicated that vehicular emissions were the principal sources especially within the lower section of the river while biomass burning had moderate contribution. The distribution, temporal trend and source apportionment suggest the containment of industrial-derived sources of PAHs in the river. From an ecological point of view, the risk posed by PAHs in the Brisbane River sediment appears to be low. Nevertheless, when the investigated sites were ranked using multi-criteria decision making methods(MCDM) the commercial stratum was the most contaminated. Assessment of potential risks posed by incidental dermal exposure to PAHs revealed some degree of cancer risk, especially to children.
Spatial-temporal distributions, sources identification and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in overlying water and surface sediments in urban river networks of Shanghai were studied. Analytical results showed that there was a significant seasonal variation in concentrations of ∑16PAHs in water, suspended particulate matter (SPM) and sediment phases in this study area. The PAHs pollution in these multi-phases were in the medium level compared with other areas around the world, and the levels of PAHs contamination in SPM and sediment phases in hierarchical rivers showed TS (the third-order stream) > FS (the first-order stream) > SS (the second-order stream). Two manners of isomer ratios and principal component analysis (PCA) were used to identify PAHs origins, and suggested that combustion processes are dominant for PAHs sources. The ratios of PAHs origins by fossil fuels combustion, coke burning and crude oil in hierarchical rivers were determined with FS > SS > TS in SPM and sediment phases, and the ratio of PAHs origins by traffic emissions was analyzed with TS > SS > FS. PAHs in water samples have a certain impact on aqueous ecological system especially due to the fact that the ∑ceq values of nine PAHs were calculated from 0.715 to 15.831 μg/L in winter, which inferred serious ecological risk to some special aquatic organisms. The calculations of MERMQ in sediment samples showed that the MERMQ values ranged from 0.021 to 1.209 in winter and 0.019 to 0.643 in summer, which suggested high toxicity at six sampling sites in winter and only one location in summer due to high levels of PAHs. Furthermore, the toxicity degree of sediments were demonstrated with TS > FS > SS.
The Yellow River Delta (YRD) is a large region of China with complex pollution sources and a long history of environmental deterioration. Despite this, relatively little data exists on the status of important contaminants of concern in this region. Here, we review the literature on the status of key persistent organic pollutants (POPs) of concern including organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in the YRD. Sources, source identification methods, and spatial distribution patterns are presented. Additionally, POPs contamination levels reported in the literature were evaluated against popular regulatory limits worldwide to form a basis for overall environmental health. Our review determined that OCPs in the YRD originated mainly from current pesticide use and past agricultural pesticide application. Sources of PAHs included petrochemical inputs, coal fired plants, and wood combustion. PCB levels were impacted by the petrochemical industry as well as waste disposal of PCB containing equipment. OCPs exhibited a spatial distribution pattern that increased along the urban-rural gradient, while the opposite was seen for PAHs and PCBs. Comparisons of POPs contamination levels in the YRD with popular regulatory limits suggest that the extent of PCB contamination all mediums (sediment, soil, water, and biota) exceeded that of PAHs and OCPs. Overall pollution levels in the YRD seem to be in control; however, levels from heavily polluted point sources raise numerous concerns about the ecological health of the region and require more attention from regulatory authorities.
We assessed polycyclic aromatic hydrocarbons in urban stormwater and odonates. • Contamination (amounts and agents) differed between water and odonate tissues. • Local factors were more important than landscape factors on PAH levels. • PAHs did not accumulate along a stormwater gradient. a b s t r a c t Polycyclic aromatic hydrocarbons (PAHs) are toxic organic pollutants produced from combustion. Associated with urban runoff, they have been detected worldwide in urban wetlands. Because PAHs and their associated metabolites are often carcinogenic, mutagenic, and teratogenic, they can pose significant risks to wetland-dependent organisms. We investigated the occurrence of 16 PAHs within water samples and tissues of damselflies (Odonata: Enallagma civile, a flagship group of predatory wetland insects) from seven urban wetlands (known regionally as playas) along a constructed stormwater gradient in Lubbock, Texas. PAH detections from water samples were highly variable across sites and dates, with naphthalene and pyrene occurring most often. PAH detections in adult damselflies were also variable but significantly different from corresponding water samples (suggesting bioaccumulation rather than passive chemical exposure), with naphthalene and fluoranthene occurring most often. The number of specific PAH detections was significantly associated with percent impervious surface within 300 m of a playa, but not with position along the stormwater gradient or number of drainage inflows. Therefore, for the urban playas and odonates of Lubbock, local factors were more important in determining PAH contamination than were landscape-level factors. PAH contamination can be reduced in future urban landscape planning and design by minimizing the amount of impervious surface around stormwater retention ponds, even if they are linked along a hydrologic gradient.
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.
In this study, three receptor models [factor analysis/multiple linear regression (FA/MLR), positive matrix factorization (PMF) and UNMIX] were applied seasonally to investigate the source apportionment of PAHs in the atmospheric environment of Alexandria, and a lifetime cancer risk was assessed. ∑44 (gas+particle) PAH concentrations varied from 330 to 1770ngm(-3) and 170-1290ngm(-3) in the summer and winter seasons respectively. PAH concentrations at the industrial sites were significantly higher than at the traffic and residential sites during the winter season (p<0.001). Summer PAH concentrations were significantly higher than the winter season at the traffic sites (p=0.027). Results obtained from the three receptor models were comparable. Vehicle emissions, both diesel and gasoline contributed on average 36.0-49.0% and 19.0-34.0% respectively, natural gas combustion 11.0-27.0% and, during the summer only, also evaporative/uncombusted petroleum sources 8.00-18.0%. Seasonal trends were found for the gasoline emission source. Overall, PMF and UNMIX models afforded better source identification than did FA/MLR. The lifetime cancer risk assessment showed that incremental lifetime cancer risks (ILTCRs) were greater than the acceptable level of 10(-6) through dermal and ingestion routes at all the investigated sites and through the inhalation route at the industrial and traffic sites only. Total ILTCRs (6.64×10(-3)-4.42×10(-2)) indicated high potential risks to the local residents.
Matching, marine sediment chemistry, and toxicity data(n = 1,513), compiled from three studies conducted in the United States, were analyzed to determine both the frequency of acute toxicity to amphipods and average percentage survival in laboratory bioassays within ranges in toxicant concentrations. We determined that the probability of observing acute toxicity was relatively low (<10%) and that average control-adjusted survival equaled or exceeded 92% in samples in which sediment quality guidelines were not exceeded. Both the incidence of toxicity increased and average survival decreased as chemical concentrations increased relative to the guidelines. In sediments with highest contaminant concentrations, 73 to 83% of the samples were highly toxic, and average control-adjusted amphipod survival was 37 to 46%. Results of this study confirm that the relationships between sediment chemical concentrations and toxicity reported in a previous study were robust. Further, they indicate that numerical guidelines for saltwater sediments can be used to estimate the probability of observing toxic effects in acute amphipod tests.
Polycyclic aromatic hydrocarbons (PAH) can be degraded in the rhizosphere but may also interact with vegetation by accumulation
in plant tissues or adsorption on root surface. Previous studies have shown that arbuscular mycorrhizal (AM) fungi contribute
to the establishment and maintenance of plants in a PAH contaminated soil. We investigated the fate of PAH in the rhizosphere
and mycorrhizosphere including biodegradation, uptake and adsorption. Experiments were conducted with ryegrass inoculated
or not with Glomus mosseae P2 (BEG 69) and cultivated in pots filled with soil spiked with 5 g kg−1 of anthracene or with 1 g kg−1 of a mixture of 8 PAH in a growth chamber. PAH were extracted from root surfaces, root and shoot tissue and rhizosphere soil
and were analysed by GC-MS. In both experiments, 0.006 – 0.11‰ of the initial extractable PAH concentration were adsorbed
to roots, 0.003 – 0.16‰ were found in root tissue, 0.001‰ in shoot tissue and 36 – 66% were dissipated, suggesting that the
major part of PAH dissipation in rhizosphere soil was due to biodegradation or biotransformation. With mycorrhizal plants,
anthracene and PAH were less adsorbed to roots and shoot tissue concentrations were lower than with non mycorrhizal plants,
which could contribute to explain the beneficial effect of AM fungi on plant survival in PAH contaminated soils.
The multi-criteria decision making methods, Preference Ranking Organization METHods for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA), and the two-way Positive Matrix Factorization (PMF) receptor model were applied to airborne fine particle compositional data collected at three sites in Hong Kong during two monitoring campaigns held from November 2000 to October 2001 and November 2004 to October 2005. PROMETHEE/GAIA indicated that the three sites were worse during the later monitoring campaign, and that the order of the air quality at the sites during each campaign was: rural site>urban site>roadside site. The PMF analysis on the other hand, identified 6 common sources at all of the sites (diesel vehicle, fresh sea salt, secondary sulphate, soil, aged sea salt and oil combustion) which accounted for approximately 68.8±8.7% of the fine particle mass at the sites. In addition, road dust, gasoline vehicle, biomass burning, secondary nitrate, and metal processing were identified at some of the sites. Secondary sulphate was found to be the highest contributor to the fine particle mass at the rural and urban sites with vehicle emission as a high contributor to the roadside site. The PMF results are broadly similar to those obtained in a previous analysis by PCA/APCS. However, the PMF analysis resolved more factors at each site than the PCA/APCS. In addition, the study demonstrated that combined results from multi-criteria decision making analysis and receptor modelling can provide more detailed information that can be used to formulate the scientific basis for mitigating air pollution in the region.
The natural isotopic compositions and C/N elemental ratios of sedimentary organic matter were determined in the intertidal flat of the Yangtze Estuary. The results showed that the ratios of carbon and nitrogen stable isotopes were respectively -29.8 per thousand to -26.0 per thousand and 1.6 per thousand-5.5 per thousand in the flood season (July), while they were -27.3 per thousand to -25.6 per thousand and 1.7 per thousand-7.8 per thousand in the dry season (February), respectively. The delta(13)C signatures were remarkably higher in July than in February, and gradually increased from the freshwater areas to the brackish areas. In contrast, there were relatively complex seasonal and spatial changes in stable nitrogen isotopes. It was also reflected that delta(15)N and C/N compositions had been obviously modified by organic matter diagenesis and biological processing, and could not be used to trace the sources of organic matter at the study area. In addition, it was considered that the mixing inputs of terrigenous and marine materials generally dominated sedimentary organic matter in the intertidal flat. The contribution of terrigenous inputs to sedimentary organic matter was roughly estimated according to the mixing balance model of stable carbon isotopes.
An investigation on water quality in Gucheng Lake
- S Q Gao
- Q Zhang
- J W Zhou
- K B Wang
- B Y Wang
Gao, S.Q., Zhang, Q., Zhou, J.W., Wang, K.B., Wang, B.Y., 1996. An investigation on
water quality in Gucheng Lake, Gaochun County. Acta Acad. Med. Nanjing 16
(1), 45e46, 53.
Survey and Control Measures to Organic Pollutant in Centralized Drinking Water Sources of Jiangsu Province. Thesis for Master's degree
- M Liang
Liang, M., 2011. Survey and Control Measures to Organic Pollutant in Centralized
Drinking Water Sources of Jiangsu Province. Thesis for Master's degree. Nanjing
Agricultural University, China, p. 35.
NW Spain): a consideration of PAHs sources and abundance
- Arousa
Arousa (NW Spain): a consideration of PAHs sources and abundance. Mar.
Pollut. Bull. 95, 155e165.