Polycyclic Aromatic Hydrocarbons Contamination Levels Research Articles

Polycyclic Aromatic Hydrocarbons (PAHs) Contamination Levels in Some Commercial Olive Oils Sold on the Markets in Giresun, Türkiye

Olive oil is widely consumed worldwide and well-known for its health beneficial effects. However, polycyclic aromatic hydrocarbons (PAHs) contamination in olive oils has been a serious concern and knowledge regarding PAH concentrations in olive oils is scarce. The aim of this study was the determination and evaluation of PAH contamination levels in olive oils in the market. In this study, commercial olive oils (n=14) available in the markets of Giresun (Türkiye), including extra virgin and riviera olive oil samples, were investigated. Samples were analyzed by a gas chromatography unit coupled with a mass spectrometer. Significant amounts of PAHs were determined in all olive oil samples. The PAH contents of the samples varied between 0.04 µg kg-1 and 4637.13 µg kg-1 with the mean content of 264.61 µg kg-1. Regarding benzo[a]pyrene, 64.28% of the samples was incompatible with the EU requirements. None of the samples were compatible with the EU requirements in terms of PAH4 components (benzo[a]pyrene, benzo(a)anthracene, chrysene, and benzo[b]fluoranthene). Results showed that commercial olive oils studied in this research might contain PAHs categorized under potential carcinogens.

Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons in surface soils and plants from industrial and agricultural areas, Junggar Basin, Xinjiang

The contamination characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in different environmental functional areas are different. In this study, the contamination of PAHs in soils and common plants in typical mining and farmland areas in Xinjiang, China, was analyzed. The results showed that the contamination levels of PAHs in mining soils were significantly higher than those in farmland soils, and the mining soils were dominated by 4-5-ring PAHs and farmland soils by 3-4-ring PAHs. Analysis of their sources using a positive definite factor matrix model showed that PAHs in mining soils mainly originated from coal and natural gas combustion, and transportation processes; while farmland soils mainly came from biomass and coal combustion, and fossil fuel volatile spills. The cancer risk of PAHs in soils was evaluated using a combination of the Monte Carlo and the lifetime carcinogenic risk models, and the results showed that the overall level of cancer risk for mining soils was higher than that for farmland soils, and can put some people in high risk of cancer. For plant samples, except for individual crop samples, the contamination levels of mining plants and crops were similar, with 4-5-ring PAHs dominating in desert plants in mining areas and the highest proportion of 3-ring PAHs in crops in agricultural fields, and PAHs in both plants were mainly from biomass and coal combustion. The results of correlation analysis showed that 2-ring PAHs in crop roots were significantly positively correlated with it in corresponding soils, and some high-ring PAHs in crop leaves were significantly negatively correlated with it in corresponding soils. Therefore, there were significant differences in the pollution characteristics of PAHs in soils and common plants in mining and agricultural areas. Human health risks and ecological risks are mainly concentrated in mining areas, and appropriate intervention measures should be taken for pollution remediation.

Assessment of Polycyclic Aromatic Hydrocarbons in Urban Water Bodies: A Study of Rivers and Lakes in Dhaka, Bangladesh

Polycyclic aromatic hydrocarbons (PAHs) pose significant environmental and health risks due to their toxic properties,making their assessment in urban water bodies crucial. This study aims to evaluate the presence of three notable PAHs—anthracene, fluoranthene, and benzo[a]pyrene—in the surface water of three rivers (Buriganga, Meghna, and Turag) andtwo lakes (Hatirjheel and Gulshan) in Dhaka, Bangladesh. High-performance liquid chromatography with fluorescencedetector (HPLC-FD) was employed and validated for PAH determination, using solid phase extraction (SPE) withpreconditioned C-18 SPE cartridge for sample extraction. Calibration showed excellent linearity with correlation coefficient (R²) ≥ 0.999. The limits of detection (LODs) were 200 ng/L for anthracene and 0.63 ng/L for both fluoranthene and benzo[a]pyrene, with corresponding limits of quantification (LOQs) of 660 ng/L and 2.08 ng/L, respectively. Percent recovery was 91.38% for anthracene, 85.49% for fluoranthene, and 95.72% for benzo[a]pyrene, with relative standard deviations (RSD) of 5.27, 17.55 and 2.84%, respectively. Most water samples had PAH levels below detection limits (bdl) such as anthracene (bdl-1789.57 ng/L), fluoranthene (bdl-1309.23 ng/L), and benzo[a]pyrene (bdl-25.17 ng/L), and the detected concentrations were significantly lower than WHO and USEPA guideline values. This indicates a relatively low level of PAHs contamination in the studied water bodies. Dhaka Univ. J. Sci. 72(2): 75-83, 2024 (July)

Application of low-density polyethylene (LDPE) passive samplers for monitoring PAHs in groundwater

Equilibrium passive sampling continues to find increasing use for performing in situ assessments and monitoring of hydrophobic organic compounds (HOCs). Although this method has been successfully used in several field studies including open surface waters and sediments, comparatively, their use in groundwater has been very limited. In this study, low-density polyethylene (LDPE) passive samplers were deployed for 80 days in three groundwater wells contaminated with polycyclic aromatic hydrocarbons (PAHs). Prior to deployment, LDPE was loaded with performance reference compounds (PRCs) consisting of deuterated PAHs and their release used to ascertain system equilibrium. Within the 80-day deployment period, LDPE-groundwater equilibrium was confirmed for PAHs with molecular weights (MWs) in the range of 178 to 228 (i.e. anthracene, chrysene). Measured freely dissolved concentrations (Cw) were between one to three orders of magnitude lower than the total filtered concentrations (Ctotal) in the studied wells. The sum of PAHs (ΣPAHs) measured based on Cw and Ctotal were 2.05, 0.07 and 29.2 μg L−1 and 197, 59.7 and 1010 μg L−1, at wells 1, 2 and 3, respectively. A separate dataset, comprising long-term (2010 to 2022) concentrations of PAHs in total (i.e., unfiltered) groundwater, is also presented to provide insight into PAH contamination levels at the assessed groundwater wells based on conventional measurement. Estimated in situ LDPE daily clearance volumes (2.34 to 27.56 Ld−1) for the target analytes were far less than the daily turnover of ground water (144 to 348 Ld−1) encountered in the wells eliminating the possibility of depletive sampling of the groundwater by the passive samplers. These results represent the first published study on the practical application of equilibrium passive sampling using LDPE for monitoring and quantitatively assessing PAHs in groundwater. Also, this work demonstrates that LDPEs are a useful tool for measuring the Cw of PAHs in groundwater, a critical contaminant in many ecological and human health risk assessments.

Preliminary study for Polycyclic aromatic Hydrocarbons mobilization from contaminated marine sediment using synthetic and natural surfactants

The persistent presence of Polycyclic Aromatic Hydrocarbons (PAHs) in soils and sediments due to their chemical properties requires new methods to mobilize and make them more available for remediation purposes. In this work, the evaluation of the abilities of eight different non-ionic sugar-based and totally biodegradable surfactants, such as synthetic alkyl polyglycosides (APGs), biological sophorolipids (SLs) and biological rhamnolipids (RLs), was conducted in order to provide a preliminary guideline for the selection of the surfactant and the technical approach for PAHs extraction from the sediment. The reference sample was a marine sediment collected from Bagnoli (Naples, Italy) that was characterized to evaluate the level of PAHs contamination, which resulted equal to 3.51 g Kg−1 of total PAHs in the sediment. By using surfactants solutions with a surfactant concentration five times greater than critical micelle concentration (Cs = 5x CMC), a preliminary washing test in batch configuration was conducted, then followed by multiple consecutive washes (MCW) of the sediment to assess the solubilization of PAHs from the sediment by the action of selected surfactants. The results show an evident advantage given by the employment of each studied surfactant in mobilizing PAHs, compared to distilled water as benchmark. In detail, the synthetic alkyl polyglycosides APG2 led to a 3.4 % of total PAHs mobilization in the preliminary washing test with a maximum peak of 9.8 % for a single compound. The MCW test demonstrates that more consecutive washes can increase the amount of total PAHs removed, with a similar contribution from each wash, and that biosurfactants can be more attractive after several washes thanks to the increased capacity of PAHs mobilization. Interestingly, the high efficiency of surfactant to mobilize PAHs makes the soil washing a more attractive technology for removing PAHs from the marine sediments.

Systematic underestimation of polycyclic aromatic hydrocarbon aqueous concentrations in rivers

Polycyclic aromatic hydrocarbons (PAHs) are a widespread group of organic contaminants whose presence in water bodies is cause of severe concern. With few exceptions, the majority of PAHs is hydrophobic, presents a high adsorption affinity, and is thus primarily transported within river systems during high-flow events together with suspended particulate matter (SPM). Evidence exists of analytical challenges related to the incomplete extraction of PAHs adsorbed to solids and thus to a potential negative bias in the chemical analysis of PAHs in bulk water samples with high SPM content. Despite this, partly due to the elevated efforts required to collect representative samples containing sufficient SPM for the separate PAH analysis in this matrix, several investigations rely on the analysis of aqueous samples. This study tests the hypothesis that surveys based exclusively on bulk water may lead to a systematic underestimation of the real contamination level and transport of PAHs in rivers. Six high-turbidity events were examined in three Austrian rivers applying time-integrated sampling and simultaneously analyzing PAHs in total bulk water, filtered water, SPM, and supernatant. Despite an unavoidable degree of uncertainty in such challenging sampling scheme, the results indicate that measurements performed with best available standard methods in bulk water samples determined in average only about 40% of the theoretically expected total PAHs concentrations derived from the analyses in SPM. Such deviation has important implications for the reliable assessment of the compliance with environmental quality standards as well as for surveys aimed to estimate riverine loads, validate emission models, and understand the transport dynamics of PAHs in rivers. Whereas the first objective, e.g., in European countries, is alternatively achieved via monitoring in biota, the latter ones require efforts directed to complement monitoring campaigns with separate sampling of SPM, with monitoring of suspended solids transport to appropriately select and interpret the results of water samples and to improve the chemical analysis of PAHs in bulk water samples with high solids content.

Polycyclic aromatic hydrocarbons (PAHs) pollution and risk assessment of soils at contaminated sites in China over the past two decades

With rapid urbanization in China, soil pollution at contaminated sites has emerged as a significant concern in the environmental protection plan. Moreover, extensive research has focused on the analysis of other major contaminants. However, over the past two decades, only a few studies have systematically analyzed polycyclic aromatic hydrocarbons (PAHs) in contaminated soils, particularly their source identification, contamination level assessment, and risk evaluation. This study addressed these research gaps by comprehensively evaluating soil PAHs contamination at these sites through the collection and screening of relevant literature data from the past 20 years using a “front page filtering” approach. The results suggested that the most contaminated sites in China were associated with petrochemical plants, steel mills, and coking plants. Coal/biomass burning emerged as the predominant source of PAHs pollution in the soils of contaminated sites across China. Overall, the soils of contaminated sites exhibited relatively low levels of PAHs contamination. The single-factor index method showed that benzo(a)pyrene (BaP) was the PAH monomer with the highest contamination level. Geographically, Northeast and North China exhibited relatively higher contamination levels and ecological risks. Moreover, PAHs posed significant health hazards, as they exhibited significantly high toxic effects on the respiratory system, carcinogenicity, aromatic hydrocarbon receptors, estrogen receptors, and antioxidant response elements. Additionally, children and youths faced higher health risks than adults. The findings from this study provide a solid basis for developing strategies to manage PAHs at contaminated sites in China.

Polycyclic aromatic hydrocarbons contamination levels of dried herbal teas and their infusions

Polycyclic aromatic hydrocarbons contamination levels of dried herbal teas and their infusions

Occurrence, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in the Amazon river

The Amazon is the largest river by discharge volume and one of the most biodiverse biomes in the world. Lately, there has been a rapid increase of the urban population in the region, which has been translated into a growing emission of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) into surface water bodies. This study provides the most comprehensive evaluation of the PAH contamination levels in surface waters of the Amazon basin. We investigated the occurrence and potential sources of 16 priority PAHs and characterised their risks for freshwater ecosystems. For this, we took 40 water samples from different sites along the Brazilian part of the Amazon River, including three major tributaries, and smaller rivers crossing the main urban areas. The results of this study show that PAHs are widespread contaminants in rivers of the Brazilian Amazon. The sum of the total concentration of the 16 priority PAHs reached values of 134 ng L−1 in the Amazon River, and 163 ng L−1 near densely populated areas. On the other hand, the total PAH concentration was generally lower in the monitored tributaries. In most samples, the contamination pattern was dominated by high molecular weight PAHs, suggesting a major contribution of pyrogenic sources, although petrogenic contamination was also present in some locations near urban areas. We assessed ecological risks posed by PAH mixtures using a hazard index. The results indicated that PAH contamination is not likely to pose direct toxic effects for Amazonian freshwater organisms, however continued monitoring is recommended near densely populated areas.

Use of Preliminary Exposure Reduction Practices or Laundering to Mitigate Polycyclic Aromatic Hydrocarbon Contamination on Firefighter Personal Protective Equipment Ensembles.

Chronic health risks associated with firefighting continue to be documented and studied, however, the complexity of occupational exposures and the relationship between occupational exposure and contaminated personal protective equipment (PPE) remains unknown. Recent work has revealed that common PPE cleaning practices, which are becoming increasingly more common in the fire service, are not effective in removing certain contaminants, such as polycyclic aromatic hydrocarbons (PAHs), from PPE. To better understand the relationship between contaminated firefighter PPE and potential exposure to PAHs, and to gain further understanding of the efficacy of cleaning practices, we used a standardized fire exposure simulator that created repeatable conditions and measured PPE surface contamination levels via wipe sampling and filters attached to firefighter gear worn by standing mannequins. This study examined the effects of repeated (40 cycles) PPE cleaning (laundering and on-scene preliminary exposure reduction (PER) techniques) and repeated exposures on PAH concentration on different surfaces. Further exploration included examination of contamination breakthrough of turnout jackets (comparing outer shell and interior liner) and evaluation of off-gassing PAHs from used gear after different cleaning treatments. When compared by jacket closure type (zipper and hook and dee), total PAH concentration wiped from gear after exposure and cleanings showed no significant differences. Regression analysis indicated that there was no effect of repeated exposures on PAH contamination levels (all sampling sites combined; before fire 10, 20, and 40; after fire 1, 10, 20, and 40; p-value > 0.05). Both laundering and on-scene PER significantly reduced contamination levels on the exterior pants and helmets and were effective at reducing PAH contamination. The jacket outer shell had significantly higher PAH contamination than the jacket liner. Both laundering and wet soap PER methods (post-fire) are effective in reducing surface contamination and appear to prevent accumulation of contamination after repeated exposures. Semi-volatile PAHs deep within the fibers of bulky PPE are not effectively reduced via PER or machine laundering, therefore, permitting continued off-gassing of these compounds. Further research is needed to identify the most effective laundering methods for firefighter turnout gear that considers the broad spectrum of common contaminants.

Polycyclic Aromatic Hydrocarbons (PAHS) Levels and Toxicity in Herbal Teas Marketed in Malaysia using Quechers and GC-FID

In line with the growing health trend in Malaysia, more consumers drink herbal tea for medicinal benefits. However, herbal tea products could be contaminated with polycyclic aromatic hydrocarbons (PAHs) from various production sources. There is a little study focused on the detection of PAHs in herbal tea species distributed in Malaysia. This study was performed to investigate PAHs content and toxicity in selected commercial herbal teas in Malaysia. A total of seven different Malaysian herbal tea samples were extracted using QuEChERS extraction method and the contamination level of PAHs were evaluated using gas chromatography (GC) with a flame ionization detector (FID). The total content of 10 PAHs (∑10PAHs) in the herbal tea samples ranged from 2.53 to 9.39 µg/kg. Acenaphthene, fluorene, phenanthrene and anthracene were the most abundant compounds with 53% contribution of all PAHs content. All tested herbal teas species showed low toxic equivalency (TEQ) values ranging from 0.0027 to 0.1148. The least contaminated samples were Strobilanthes crispus, Senna alata, Orthosiphon aristatus, Clinacanthus nutans, and Stevia rebaudiana.

Health Risks Associated with Polycyclic Aromatic Hydrocarbons (PAHs) in Dustfall Collected from Universities in Wuhan, China

Atmospheric dustfall samples from the libraries and dormitories of 14 universities in Wuhan, China, were collected and analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs). The results showed that the levels of Σ16PAHs in the dustfall from libraries varied from 2.45 to 13.4 μg·g−1, with an average value of 5.06 μg·g−1, while that of dormitories ranged from 2.61 to 10.6 μg·g−1, with an average of 5.19 μg·g−1. The compositions of PAHs in library and dormitory dustfall were similar, and they were dominated by high molecular weight PAHs (HMW-PAHs) (including fluoranthene, benzo(b)fluoranthene, and chrysene), which accounted for 79.2% of the total PAHs. Spatially, the higher levels of PAHs contamination were mainly distributed in areas with high population density and heavy traffic, which suggests that anthropogenic activities made an important contribution to the PAHs emissions. The diagnostic ratios and principal component analyses (PCA) indicated that combustion-related anthropogenic sources, such as petroleum, coal, and biomass combustion, as well as vehicular traffic emission, were the main sources of PAHs bound to dustfall. The toxic equivalent concentrations (BaPeq) of dustfall-bound PAHs ranged from 271 to 2510 μg·kg−1. According to the health risk assessment results, dermal contact was the predominant exposure pathway, followed by ingestion and inhalation. The incremental lifetime cancer risks (ILCRs) of exposure to PAHs in dustfall was 1.230 × 10−6−1.140 × 10−5, which indicates that there are low potential carcinogenic risks in the universities.

Assessment of biological community in riparian zone contaminated by PAHs: Linking source apportionment to biodiversity

Riparian zone, an important land-water interface, plays an essential role in maintaining the ecological health of rivers, whereas the effects of Polycyclic aromatic hydrocarbons (PAHs) on the health of biological communities in riparian groundwater remain undetermined. To understand the responses of multiple communities to environmental variables, the distribution and ecosystem risk of 16 PAHs have been investigated in the Beiluo River, China. The distribution of multiple communities in riparian groundwater was investigated by environmental DNA metabarcoding, including 16S rRNA, 18S rRNA, and COI gene sequencing for bacteria, microbial eukaryotes (including algae, fungi, and protozoa), and metazoan, respectively, followed by correlation analysis between multiple communities and PAH contamination levels. The concentration of PAHs in the Beiluo River ranged largely from 35.32 to 728.59 ng/L. Here, the Shannon's diversity index of bacteria (Firmicutes) decreased possibly due to the occurrence of Pyrene, which mainly derives from coal and biomass combustion. Furthermore, the reduced richness of fungi (Ascomycota, Basidiomycota) and algae (Chlorophyta, Chrysophyceae) can be attributed to the presence of medium molecular weight (MMW) PAHs (Pyrene, Benz(a)anthracene, Chrysene), and low molecular weight (LMW) PAHs (Naphthalene, Fluorene, Phenanthrene). The richness and Shannon's diversity index of metazoan (Arthropoda) were promoted owing to MMW PAHs (Chrysene, Fluoranthene) generated from coal and biomass combustion and traffic emission. The ecological risk of PAHs in the groundwater environment of the Beiluo River was characterized as low to medium, where LMW and MMW PAHs posed higher risk than the high molecular weight (HMW) compounds. Overall, this study provides insights into the structures of riparian multi-biological communities altered by PAHs.

Inhalation Bioaccessibility of Polycyclic Aromatic Hydrocarbons in PM2.5 under Various Lung Environments: Implications for Air Pollution Control during Coronavirus Disease-19 Outbreak.

Global spread of coronavirus disease-19 (COVID-19) is placing an unprecedented pressure on the environment and health. In this study, a new perspective is proposed to assess the inhalation bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 for people with various lung health conditions. In vitro bioaccessibility (IVBA) was measured using modified epithelial lung fluids simulating the extracellular environment of patients with severe and mild lung inflammation. The average PAH IVBA in PM2.5 of 24.5 ± 4.52% under healthy conditions increased (p = 0.06) to 28.6 ± 3.17% and significantly (p < 0.05) to 32.3 ± 5.32% under mild and severe lung inflammation conditions. A mechanistic study showed that lung inflammation decreased the critical micelle concentrations of main pulmonary surfactants (i.e., from 67.8 (for dipalmitoyl phosphatidylcholine) and 53.3 mg/L (for bovine serum albumin) to 44.5 mg/L) and promoted the formation of micelles, which enhanced the solubilization and competitive desorption of PAHs from PM2.5 in the lung fluids. In addition, risk assessment considering different IVBA values suggested that PAH contamination levels in PM2.5, which were safe for healthy people, may not be acceptable for patients with lung inflammation. Because of the large number of COVID-19 infections, and the fact that some survivors of COVID-19 were observed to still show symptoms of interstitial lung inflammation, the finding here can provide important implications for both the scientific community and policy makers in addressing health risk and air pollution control during the COVID-19 outbreak.

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) Contamination Levels in Underutilized Grains (Guinea Corn, Pigeon Peas and Bambara Nut) in South East Nigeria

Polycyclic aromatic Hydrocarbons, PAHs are harmful persistent organic pollutants formed by incomplete combustion of organic matter. They are carcinogenic and mutagenic and can occur in foods. These underutilized grains- guinea corn, pigeon peas and bambra nut are commonly consumed in South East Nigeria. This study aimed to quantitatively determine the polycyclic aromatic hydrocarbons contamination levels in these underutilized grains (guinea corn, pigeon peas and bambara nut) commonly consumed in Eastern part of Nigeria. The sixteen PAHs were determined in the grain samples using gas chromatography coupled with flame ionization detector, GC- FID after extraction by sonication. The concentrations (×10^-2 µg/kg) of ∑16 PAHs in the analyzed samples were in the range of 24.07 to 36.49 in red guinea corn and red pigeon peas respectively. The lower molecular weight polycyclic aromatic hydrocarbons, LMW-PAHs total mean concentrations (×10^-2 µg/kg) varied from 6.217±0.442 in red guinea corn to 10.423±6.661 in pure white bambara nut at the percentages of 25.83% and 33.51% respectively. While the high molecular weight polycyclic aromatic hydrocarbon, HMW-PAHs varied from 14.835±7.178 to 27.657±14.190 respectively in white pigeon peas and red pigeon peas at the percentages of 59.34% and 75.79%. The total mean concentration levels (×10^-2 µg/kg) of ∑8 carcinogenic PAHs in samples ranged from 10.913±4.215 in white pigeon peas to 17.444±7.023 in red pigeon peas. The sixteen priority PAHs were detected in all the samples at a very low level, below the maximum allowable limit- 1.0µg/kg established by European Food Safety Authority, EFSA for cereals and cereal-based products. But this can be harmful to human being at long time accumulation in the body. Permissible limit of PAHs in legume grains should also be established.

Concentrations of the 16 US EPA PAHs in 86 Vegetable Oil Samples

A wide survey of the distributions of polycyclic aromatic hydrocarbons (PAHs) in vegetable oils (n = 86) for human consumption from manufacturers and retail shops in China were conducted by GC-MS following extraction with acetonitrile and purification using silica gel solid phase. Levels of BaP and PAH4 in 37 and 34 samples, respectively, were not in line with maximum permitted limit set by EU regulations. The three-ring and four-ring PAH compounds were predominant in vegetable oils, followed by 2 rings, which may be attribute to the truth that low molecular weight PAHs are prone assimilated by plant roots than high-ring PAHs, and are mainly produced under low temperature (<200 °C) processing conditions. The level of PAHs contamination found in this study in oil products should prompt a suitable intervention strategy to meet the health needs of consumers. Considering the vegetable oil categories, the levels of 16 PAHs in peanut and sesame oil were higher than other oils. This may be related to the two oils mostly extracted from roasted seeds for the development of flavor or aromatic in China. To hold the flavor of the crude oils, they were not refined. The health risk assessment of PAHs showed that there was a potential carcinogenic risk for the vegetable oil intake in China, but it has not yet reached the priority risk level.

Environmental occurrence, spatial distribution, and source identification of PAHs in surface and groundwater samples of Abou Ali River-North Lebanon

This paper assesses the concentrations, spatial distribution, compositional patterns, and sources of polycyclic aromatic hydrocarbons (PAHs) in the dissolved aqueous phase along the Abou Ali River course. The 16 priority PAHs, listed by the USEPA, were investigated in surface- and groundwater samples for 2years starting August 2015 and ending in March 2017. Statistical analysis was done by using the ANOVA test at p < 0.05. The spatial distribution analysis and illustration were done using the ARC GIS software. The total PAHs concentration in surface and groundwater samples varied between not detected to 15.162ngmL-1 and not detected to 0.635ngmL-1, respectively. The highest concentration of PAHs in surface water was observed at site S16, downstream of the river. However, the absence of PAHs was noticed at sites S1 and S2 of the upstream. The contamination levels of PAHs were found to be high in surface water samples, and low in groundwater samples. The 5- and 6-ring PAHs were the most abundant species among others in surface water samples, whereas the 3-ring PAHs were the most abundant in groundwater. Pyrogenic inputs deriving from fuel combustion, incineration, and miscellaneous burning were found to be the main PAH sources in surface and groundwater without ignoring the contribution of petrogenic inputs in some areas.

Polycyclic aromatic hydrocarbons (PAHs), arsenic, chromium and lead in warty crab (Eriphia verrucosa): occurrence and risk assessment

This study assesses the PAH and heavy metal levels in muscle of warty crabs (Eriphia verrucosa), from the northern coast of the Campania region improving the data on toxic contaminants in this crustacean. The results showed a minimal PAH contamination; the mean concentrations were as follows: 0.2, 1.6 and 1.7 μg kg-1 wet weight (ww) for BaP, PAH4 and PAH6, respectively. Regarding the levels of the two PAHs not included in the European regulations, the BkF mean concentration was 0.1 μg kg-1 ww, while DahA was detected only in 10.7% of samples. Pb and Cr were also detected at low levels with mean values of 0.068 and 0.468 mg kg-1 ww, respectively; instead, high As levels, with a mean value of 5.021 mg kg-1 ww, were found. Considering the EWIs and the ILCRs calculated in this study, the PAH, Pb and Cr contamination levels found in the edible part of the crabs resulted safe for human consumption. Contrariwise, the ILCR calculated for the As exceeded the acceptable level of cancer risk, although the calculation did not refer to the inorganic form which is the only one recognized as carcinogenic. Hence, this study shows that warty crabs can accumulate environmental contaminants in their muscle tissue representing an important route of exposure to these toxics for the local population that regularly consumes them. This finding highlights the importance of monitoring the presence of these pollutants in crabs and in general in all fish and seafood in order to ensure food safety for consumers.

Health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the soil around thermal power plants in southwest China

This study aimed to evaluate the PAH contamination levels and to assess the health risk of PAH in soils of two typical thermal power plants. The PAH content was detected using gas chromatography-mass spectrometry (GC-MS). The carcinogenic risk and the hazard quotient were assessed for health risk using the “Chinese Technical Guidelines for Risk Assessment of Contaminated Sites HJ 25.3-2014.” The results showed that the average concentration of Σ16PAHs in the soils around thermal power plants A and B are 7436 μg/kg and 8975 μg/kg, respectively indicating heavily pollution. The comprehensive carcinogenic risk of PAHs in thermal power plants A and B ranged from 0.26 × 10−6 to 4.16 × 10−6. Forty percent of the sampling sites exceeded the acceptable risk level (10−6), which is a potential carcinogenic risk to the workers. Among the seven kinds of carcinogens, Bap (39.91%) and DBA (36.10%) had the highest carcinogenic risk. Oral ingestion (57.22%) and skin contact (42.49%) were the major exposure pathways that could be blocked by wearing masks, gloves, and protective clothing. The control values for oral ingestion (0.32717 mg/kg) of DBA and Bap with the highest contribution rate of the carcinogenic risk and the lowest control value were selected as reference safety thresholds for PAHs in thermal power plants.

Seasonal variations of polycyclic aromatic hydrocarbons in coastal sediments of a marine resource hot spot: the case of pars special economic energy zone, Iran.

Polycyclic aromatic hydrocarbons (PAHs) are an important group of compounds of major environmental concern, which are in the class of persistent organic pollutants. Therefore, the key purpose of this research was to analyze seasonal fluctuations and to determine the probability of polycyclic aromatic hydrocarbons in coastal sediments of the Iranian Marine Resource Center based on the evaluation of 16 US-EPA important PAH compounds. These compounds have been collected from intertidal sediments located in the marine resources of southern Iran in different seasons. These samples of the surficial sediment were collected at the PSEEZ area using a stainless steel grab sampler in four seasons, from depths between 0.5 and 30m. Surface sediment samples were removed by spoons and carefully placed in an aluminum foil; they were taken to the laboratory on ice and held at 20° C until their study. After extraction, by using a rotary evaporator apparatus, samples were condensed. The assay was added to roughly 2g of activated copper flasks in the refrigerator for 36h for desulfurization. Among different seasons, the highest concentration was observed in winter, with a mean of 281.3ngg-1. According to ecological risk assessment (concentrations of possible effects, low effect range, degree of threshold effects, and median effect range), PAH risks in surface sediments of PSEEZ were lower than the threshold results levels (TEL), possible effects levels (PEL), low range of effects (ERL), and median range of effects (ERM), indicating that a biological effect would rarely occur. The dry weight scale of the concentration of ∑PAHs ranges from 145.7 to 348.42ngg-1 with a mean quantity of 260.52ngg-1. Therefore, according to the amount of ∑PAH concentration, the sediments in the PSEEZ area indicated moderate to heavy pollutions. In this way, the sedimentary surface ecosystems of the Persian Gulf were considered as moderately polluted compared with other ecosystems worldwide. Our study highlighted some of the research gaps in PAH contamination studies and the level of PAH contamination. Therefore, this study will provide a scientific background, planning, and policies for PAH pollution control and environmental protection in Iran and similar regions around the world.