High Concentrations Of Polycyclic Aromatic Hydrocarbons Research Articles

Distribution of polycyclic aromatic hydrocarbons and heavy metals in soil following a large tire fire incident: A case study

In October 2019, a fire occurred in a tire-recycling facility in Alytus (Lithuania), where around 5000 t of tires had been stored. Only after 10 days was the fire completely extinguished, and the potential contamination of the surrounding environment has raised a large public concern. With an aim to assess the pollution level and pollutants distribution in the surrounding area, we conducted a study on polycyclic aromatic hydrocarbons (PAHs) and heavy metals. High concentrations of total PAHs were found inside the fire zone (315–5872 ng g−1 dw), whereas those detected in the surrounding soils were significantly lower (1.9–72 ng g−1 dw). Some areas with higher anthropogenic impact were found to contain PAH concentrations as high as 70198 ng g−1 dw. Concentrations of Cr, Zn, Ni, Cu, Pb were in the range of 1.1–93.9; 20.7–227.5; 0.2–35.7; 0.9–21.3; 0.9–102.9 μg g−1, respectively. Zn was the prevailing metal in the fire zone, elevated concentrations of Cr, Ni and Cu were also detected in this area. Principal component analysis (PCA) revealed several locations affected by the fire. The one located the closest to the fire zone was found to be highly contaminated with the heavy metals, just like the whole fire zone. Increase of the carcinogenic risk was observed in the fire zone, but no significant risk was detected in the fire-affected stations. The highest carcinogenic risk was detected in the zones with high anthropogenic loading (traffic and urban activities).

PAH residue and consumption risk assessment in four commonly consumed wild marine fishes from Zhoushan Archipelago, East China Sea

The concentration, constitution, distribution, possible sources, and associated consumption risks of polycyclic aromatic hydrocarbons (PAHs) in four marine fishes in the Zhoushan Archipelago were investigated. The concentrations of PAHs in the edible muscle of these four fishes ranged from 34.7 to 108 ng/g wet weight. Four-ring and six-ring PAH congeners constitute the most and least percentages of the total PAHs, respectively. The highest PAH concentrations were found in Mugil cephalus, followed by Sebastiscus marmoratus, Lateolabrax maculatus, and Collichthys lucidus. The highest PAH concentrations were found at the sampling island Liuheng, followed by Gouqi, Qushan, Dongji, and Zhujiajian. PAH concentrations in wet weight were remarkably different among these four fish species but not among different locations. High-molecular-weight congeners predominated the PAH composition pattern in most of the samples. Results showed that the consumption of M. cephalus might have potential carcinogenic risk. This study provided baseline data on PAH concentrations in seafood and consequent human consumption risk.

Spatial distribution and temporal variation of polycyclic aromatic hydrocarbons in runoff and surface water

This study aims to investigate the spatial distribution of and temporal variation in the phase distribution, emission sources, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in runoff and in surface water mixed with runoff discharge. The samples were collected at semi-rural, residential, and industrial sites in Ulsan, South Korea, from April to October 2016. The industrial site had the highest PAH concentrations in the runoff and surface water due to the higher PAH levels found in the surrounding environmental media. The PAH phase distributions were relatively similar between the sampling sites, with dissolved PAHs (2- to 4-ring species) dominant. In July, the PAHs in the surface water were more commonly found in the dissolved phase due to the higher water temperature and dissolved organic carbon concentration. The emission sources for the PAHs were identified using principal component analysis (PCA), a dimension reduction technique, and the k-nearest neighbor (KNN) classifier, a supervised learning algorithm. It was determined that the PAHs in the runoff and surface water were likely to share similar petrogenic and pyrolysis sources for most of the sampling periods. The ecological risk of the surface water was 1.5–4.5 times lower after being mixed with runoff water, mainly due to dilution effects. The ecological risk for surface water was highest in July because of the higher PAH concentrations. This study contributes to the understanding of PAHs in runoff and in surface water affected by runoff discharge.

Human health risks from brominated flame retardants and polycyclic aromatic hydrocarbons in indoor dust

Exposure to dust particles containing toxic compounds is linked to serious health outcomes, including cancer. The purpose of this study was to determine if indoor dust from houses and cars contained harmful levels of brominated flame retardants (polybrominated diphenyl ethers, PBDEs) and polycyclic aromatic hydrocarbons (PAHs), and to assess their potential toxicity to adults and children. In Kuwait, the median concentration of total PBDEs (Ʃ14- PBDEs) was 408.55 μg PBDEs/kg dust in houses and twice as high in cars (838.52 μg PBDEs/kg dust), while total PAHs (Ʃ16-PAHs) were similar in houses (992.81 μg PAHs/kg) and cars (900.42 μg PAHs/kg). The PBDEs and PAHs concentrations in indoor dust were related to house age and square footage, car model year, and natural ventilation. Furthermore, a higher PBDEs concentration was associated with electronic devices that operate continuously, furniture containing foam treated with PBDEs, and cars that are parked outdoors, since PBDEs tend to be volatilized under these conditions. The PAHs concentration in indoor dust increased with smoking and proximity to major roads and industrial facilities, which are major PAHs sources. The hazard quotient and total cancer risk for PBDEs in indoor dust were within safe limits, but indoor dust with higher PAHs concentrations had hazard quotients from 5.51 to 11.23 and total cancer risk of 10−3 for adults and children. We conclude that exposure to PAHs-contaminated indoor dust from houses and cars where smoking occurs can increase the cancer risk of adults and children.

Particle-bound polycyclic aromatic hydrocarbons in a rural background atmosphere of southwestern Europe

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic pollutants widely distributed in the atmosphere and well known for their carcinogenic and mutagenic properties. Over the last two decades, research about atmospheric PAHs has been focused in urban and industrial areas, while less attention has been given to rural areas. This study aims to contribute to filling this gap by analyzing the levels, sources and associated health risks of particulate PAHs in a rural coastal atmosphere of southwestern Europe (Portugal). A total of 132 PM10 aerosol samples were collected over a 3-year period, from 2014 to 2016, with a high-volume sampler and analyzed for 7 PAHs by high-performance liquid chromatography. The global average of the sum of the concentrations of PAHs (ΣPAHs) was 0.320 ± 0.597 ng/m3. Benzo[b]fluoranthene was the dominant congener in the majority of aerosol samples, with an average contribution of 25% to the ΣPAHs. A seasonal trend was repeatedly observed over the study period with higher concentrations of PAHs during the autumn and winter months. The HYSPLIT model was used to examine air mass transport pathways into the sampling site, revealing that changes in the frequency of continental air mass trajectories were a key factor explaining the seasonal variation of PAHs. Model runs also indicated that fast-moving air masses were more efficient at dispersing PAHs emitted in the surrounding region than slow-moving air masses with a similar origin (marine or continental). The average concentration of benzo[a]pyrene, a powerful human carcinogen, was found to be 0.044 ± 0.098 ng/m3, approximately two orders of magnitude lower than average values previously recorded in the most polluted European atmospheres. Diagnostic ratio analysis suggested that mobile and stationary combustion sources were equally contributing to the atmospheric load of PAHs. The estimated average lifetime lung cancer risk was below the health-based guideline level, indicating a low risk of lung cancer development associated with inhalation exposure to particle-phase PAHs.

Speculative Carcinogenicity Assessment of Polycyclic Aromatic Hydrocarbons Found in Some Anti-Diarrheal Herbal Drugs Sold in Ondo State of Nigeria

The conviction that herbal drugs have enormous health benefits has led to increase the rate of their consumption by Nigerians. The aim of this study was to assess the carcinogenic property of some popularly consumed anti-diarrheal herbal drugs via polycyclic aromatic hydrocarbons (PAHs) quantification. Three prevalent anti-diarrhea herbal drugs , Odunmo herbal drug (Hibiscus rosa-sinensis and Bacopamonnieri), Orogun herbal mixture (Hibiscus sabdariffaI and Hedera helix), and Alora herbal syrup (Aloe vera and Hibiscus sabdariffaI) were bought for the purpose of this study and they were coded as samples A, B, and C, respectively. The ultrasonic extraction of the herbal drugs was carried out using standard procedures. The crude extracts obtained were purified using a chromatographic method. The concentrations of PAHs were quantified using gas chromatography flame ionization detector (GCFID). The diagnostic indices, group distribution, toxicity equivalence and exposure dosage were estimated. The cancer risk values were theoretically speculated based on concentrations of PAHs in the tested herbal drugs, associated with the published estimates of each concentration to cause cancer and the calculated exposure doses of the anti-diarrhea herbal drug samples were within three age groups (children, Preteen and adult). The highest concentration of total PAHs was observed in sample A (58.2815mg/kg) and the lowest concentration in sample B (44.1898mg/kg), but the concentration of total PAHs in sample C was 47.4169 mg/kg. The highest percentage of carcinogenic PAHs in the anti-diarrheal herbal drugs was found in sample C (48.66%) and the lowest in sample B (38.17%). The diagnostic indices confirmed a pyrogenic source of PAHs. Group distribution of PAHs showed that the herbal drugs are weakly carcinogenic due to high concentrations of low and moderate molecular weight PAHs. The cancer risk estimated for all the age groups where below the limit established by the United State Environmental Protection Agency (USEPA) for cancer (1 x 10-6). This ascertained that the use of these herbal drugs cannot cause cancer. However, consumers of these herbal drugs should take necessary precautions as excessive intake can lead to dangerous health implications.

Sources and pollution path identification of PAHs in karst aquifers: an example from Liulin karst water system, northern China

Karst water, with constituting major sources for water supply worldwide, is vulnerable and prone to be polluted. In this study, it is reported that karst water polycylic aromatic hydrocarbons (PAHs) pollution is caused by the infiltration of surface runoff in the bared carbonate areas, which is of universal significance for the protection of groundwater resources in karst region. Hydro-geochemistry, stable isotopes (δD, δ18O and 87Sr/86Sr) and characteristic ratio method were conducted together to illustrate the concentration, distribution, sources and pollution path of polycyclic aromatic hydrocarbons in groundwater in the Liulin karst water system of northern China. The results showed that total concentration of polycyclic aromatic hydrocarbons ranged from 39.25 to 16,830 ng/L in groundwater, with Naphthalene being the dominant component, and the median value increased gradually along the flow path. The highest polycyclic aromatic hydrocarbons concentrations in karst water were mainly observed in the coal mining and the discharge areas. Based on the characteristic ratios, the polycyclic aromatic hydrocarbons in the study area mainly come from local incomplete combustion of woods, fossil fuels, coal and liquid fuels. The slight shift of δD and δ18O and moderate 87Sr/86Sr ratios suggest that the polycyclic aromatic hydrocarbons in karst water is mainly polluted by surface runoff during rain events in the bared karst region. The leakage of river water may partly contribute to the polycyclic aromatic hydrocarbons in some karst water, which normally located close to the karst water - river water mixing line. This study provides a new technical method for tracing the sources and identifying the pollution paths of organic pollution in a karst water system.

Influence of traditional Cambodian smoking practices on the concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in smoked fish processed in the Tonle Sap area, Cambodia

Aim of this work was to in detail investigate the practices of traditionally smoke-cured fish from the Tonle Sap area, Cambodia and monitoring of the concentrations of selected polycyclic aromatic hydrocarbons (PAHs). The levels of benzo(a)pyrene (BaP), sum of 4 PAHs (ƩPAH4) and total PAHs (ƩPAH12) in 57 samples of smoked fish commonly consumed in Cambodia were determined by modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) – Enhanced Matrix Lipid Removal (EMR Lipid) – Dispersive Liquid-Liquid Microextraction (DMLLE) method and analysed by gas chromatography – mass spectrometry (GC/MS). The results highly exceeded the limits given by European Commission (EU) No 1881/2006. The highest ƩPAH4 and ƩPAH12 concentrations were detected in Paralaubuca typus, 2700 μg/kg and 16,800 μg/kg, and the lowest measured in Paralaubuca barroni, 76.3 μg/kg and 537 μg/kg, respectively. The results showed significant increase of ƩPAH12 mean values between smoking times T1 (3−16 h) and T2 (1–4 days), and when fuel wood was used. Correlation between the fat content and PAHs contamination was not observed. The high concentrations of PAHs are attributed to a combination of factors (type of fuel used and length of smoking). However, other factors cannot be excluded (fire-starting technique, temperature regulation, type of heat source).

Assessment of polycyclic aromatic hydrocarbons (PAHs) in traditional breads consumed by people in Tehran city of Iran and the calculation of their daily intake

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are stable organic pollutants with proven carcinogenic properties. These substances produced as a result of incomplete burning of fossil fuels. Due to PAHs importance in people’s health, we decided to design a study to measure the amount of polycyclic aromatic hydrocarbons (PAHs) in different types of traditional bread produced in Tehran city and calculate their daily intake by consumers. Seventy-five samples of five types of bread including Lavash, Tafton, Sangak, and Barbary and bulk were randomly collected from bakeries in the city of Tehran to investigate the amount of PAHs. All extracted samples were measured by Gas chromatography–mass spectrometry (GC-MS). The separation of PAHs performed based on a solid phase magnetic extraction (MSPE) method with carbon nanotubes prepared from bread samples and the extracted samples were measured by GC-MS. Our finding showed that the mean values of aromatic hydrocarbon compounds (PAH) in the bread samples range from 0.2 to 8.7 μg kg-1. The maximum amount of aromatic hydrocarbon compounds (PAH) was in Barbary bread with amount of 8.7 µg kg−1 and the minimum value was in industrial bread (bulk) with 0.2 µgkg−1. Also, the mean value ofPAHs content in Sangak, lavash, and bulk (industrial) bread was 2.25, 2.5 and 1.66 µg kg−1, respectively. The highest and lowest mean value of aromatic hydrocarbon polycyclic compounds (PAHs) were obtained in barbaribread around 2.64 μg kg−1 and 1.59 μg kg-1 in Taftoon, respectively. Also,the result of this study showed that the Daily intake of benzopyrene in bread by consumers was below international recommended levels. According to the results, long time and high-temperature baking, also the thickness of the bread, is the main contributor of high concentration of PAHs in the bread.

Polycyclic aromatic hydrocarbons (PAHs) in urban stream sediments of Suzhou Industrial Park, an emerging eco-industrial park in China: Occurrence, sources and potential risk

In this study, urban stream sediment samples were collected in the Suzhou Industrial Park (SIP), one of the earliest national demonstration eco-industrial parks of China. PAHs were analyzed in these sediments, and concentrations of total PAHs were 180–81,000 ng g−1 (5700 ± 14,000 ng g−1). Medium molecular weight (4- ring) PAHs were predominant (42 ± 12%), followed by high molecular weight (5- and 6- ring) PAHs (31 ± 10%). No correlation was found between concentrations of PAHs and land uses of SIP in this study. Diagnostic ratios and a positive matrix factorization (PMF) model indicated that coal/biomass combustion might be the primary PAH source (61%), followed by non-combustion sources (21%) and vehicular emission (18%). According to the spatial analysis, PAHs in the sediments of SIP might be mainly associated with the coal/biomass combustion in the northeast industrial zone. Residential & commercial activities seem not to be the major causes of PAH contamination. Total PAH toxic equivalent concentrations, effect range low/effect range median values, and mean effects range–median quotient all showed that PAHs were present at a low toxicity risk level in most regions of the SIP. However, vigilance is required at some sampling sites with extremely high PAH concentrations or high mean effects range–median quotient.

The role of gut microbial community and metabolomic shifts in adaptive resistance of Atlantic killifish (Fundulus heteroclitus) to polycyclic aromatic hydrocarbons.

Altered gut microbiomes may play a role in rapid evolution to anthropogenic change but remain poorly understood. Atlantic killifish (Fundulus heteroclitus) in the Elizabeth River, VA have evolved resistance to polycyclic aromatic hydrocarbons (PAHs) and provide a unique opportunity to examine the links between shifts in the commensal microbiome and organismal physiology associated with evolved resistance. Here, 16S rRNA sequence libraries derived from fish guts and sediments sampled from a highly PAH contaminated site revealed significant differences collected at similar samples from an uncontaminated site. Phylogenetic groups enriched in the libraries derived from PAH-resistant fish were dissimilar to their associated sediment libraries, suggesting the specific environment within the PAH-resistant fish intestine influence the gut microbiome composition. Gut metabolite analysis revealed shifts between PAH-resistant and non-resistant subpopulations. Notably, PAH-resistant fish exhibited reduced levels of tryptophan and increased levels of sphingolipids. Exposure to PAHs appears to impact several bacterial in the gut microbiome, particularly sphingolipid containing bacteria. Bacterial phylotypes known to include species containing sphingolipids were generally lower in the intestines of fish subpopulations exposed to high concentrations of PAHs, inferring a complex host-microbiome relationship. Overall, killifish microbial community shifts appear to be related to a suppression of overall metabolite level, indicating a potential role of the gut in organismal response to anthropogenic environmental change. These results on microbial and metabolomics shifts are potentially linked to altered bioenergetic phenotype observed in the same PAH-resistant killifish populations in other studies.

Exposure and Recovery from Environmentally Relevant Levels of Waterborne Polycyclic Aromatic Hydrocarbons from Deepwater Horizon Oil: Effects on the Gulf Toadfish Stress Axis.

There is evidence that the combination of polycyclic aromatic hydrocarbons (PAHs) released in the Deepwater Horizon oil spill impairs the glucocorticoid stress response of vertebrates in the Gulf of Mexico, but the mechanisms are unclear. We hypothesized that inhibition of cortisol release may be due to 1) overstimulation of the hypothalamic-pituitary-inter-renal (HPI) axis, or 2) an inhibition of cortisol biosynthesis through PAH activation of the aryl hydrocarbon receptor (AhR). Using a flow-through system, Gulf toadfish (Opsanus beta) were continuously exposed to control conditions or one of 3 environmentally relevant concentrations of PAHs from Deepwater Horizon oil (∑PAH50 = 0-3 μg L-1 ) for up to 7 d. One group of toadfish was then exposed to a recovery period for up to 7 d. No changes in corticotrophin-releasing factor mRNA expression, adrenocorticotropic hormone (ACTH), or pituitary mass suggested that overstimulation of the HPI axis was not a factor. The AhR activation was measured by an elevation of cytochrome P4501A1 (CYP1A) mRNA expression within the HPI axis in fish exposed to high PAH concentrations; however, CYP1A was no longer induced after 3 d of recovery in any of the tissues. At 7 d of recovery, there was an impairment of cortisol release in response to an additional simulated predator chase that does not appear to be due to changes in the mRNA expression of the kidney steroidogenic pathway proteins steroidogenic acute regulatory protein, cytochrome P450 side chain cleavage, and 11β-hydroxylase. Future analyses are needed to determine whether the stress response impairment is due to cholesterol availability and/or down-regulation of the melanocortin 2 receptor. Environ Toxicol Chem 2021;40:1062-1074. © 2020 SETAC.

Characterization of polycyclic aromatic hydrocarbons in the surface sediments around the sunken Sanchi oil tanker

The Sanchi oil tanker collision has attracted worldwide attention for its uniqueness in history. This study investigates the contamination level, spatial distribution, sources, and ecological risk level of polycyclic aromatic hydrocarbons (PAHs) present in the surface sediments collected from around the sunken tanker. The results indicated that the total PAH contents in the study area were in the range of 26.42–226.94 ngˑg−1, with an average of 106.86 ngˑg−1. The highest PAH concentration was observed at the station closest to the Sanchi wreckage, indicating potential PAH contamination due to the accident. The PAH ratios and statistical analysis revealed that the PAHs were mainly generated by coal and fuel oil combustion, with certain petrogenic inputs. The ecological risk assessment results suggested that adverse ecological effects to the benthic ecosystem due to PAH contamination was rare. However, long-term monitoring of the local sedimentary environment is highly recommended because of the prominent presence of high molecular weight PAHs.

Multi-year Analyses Reveal Different Trends, Sources, and Implications for Source-Related Human Health Risks of Atmospheric Polycyclic Aromatic Hydrocarbons in the Canadian Great Lakes Basin

Polycyclic aromatic hydrocarbons (PAHs) are of high concern to public health due to their carcinogenic and mutagenic properties. Here, we present the first comprehensive and quantitative analysis of sources, potential source regions according to source sectors and source-related human health risks of multi-year atmospheric measurements of PAHs in the Canadian Great Lakes Basin (GLB). The highest PAH concentrations were observed at a rural residential site (Egbert), followed by two regionally representative remote sites [Point Petre (PPT) and Burnt Island]. The levels of most PAHs in the GLB atmosphere significantly decreased between 1997 and 2017, broadly consistent with the decreasing trends of anthropogenic emissions. Coal, liquid fossil fuel, and biomass burning were the most common potential sources. The potential source regions for most source sectors were identified south or southwest of the sampling sites. Risk assessment suggests potential health risks associated with the inhalation of atmospheric PAHs. On a positive note, health risks from coal combustion, liquid fossil fuel combustion, and petrogenic sources at PPT significantly decreased, directly demonstrating the success of emission control in reducing health impacts. In contrast, the health risk from forest fire-related PAH emissions may play an increasing role in the future due to climate change.

Tracking gene expression, metabolic profiles, and biochemical analysis in the halotolerant basidiomycetous yeast Rhodotorula mucilaginosa EXF-1630 during benzo[a]pyrene and phenanthrene biodegradation under hypersaline conditions.

Polyaromatic phenanthrene (Phe) and benzo[a]pyrene (BaP) are highly toxic, mutagenic, and carcinogenic contaminants widely dispersed in nature, including saline environments. Polyextremotolerant Rhodotorula mucilaginosa EXF-1630, isolated from Arctic sea ice, was grown on a huge concentration range -10 to 500ppm- of Phe and BaP as sole carbon sources at hypersaline conditions (1M NaCl). Selected polycyclic aromatic hydrocarbons (PAHs) supported growth as well as glucose, even at high PAH concentrations. Initially, up to 40% of Phe and BaP were adsorbed, followed by biodegradation, resulting in 80% removal in 10 days. While extracellular laccase, peroxidase, and un-specific peroxygenase activities were not detected, NADPH-cytochrome c reductase activity peaked at 4 days. The successful removal of PAHs and the absence of toxic metabolites were confirmed by toxicological tests on moss Physcomitrium patens, bacterium Aliivibrio fischeri, human erythrocytes, and pulmonary epithelial cells (A549). Metabolic profiles were determined at the midpoint of the biodegradation exponential phase, with added Phe and BaP (100ppm) and 1M NaCl. Different hydroxylated products were found in the culture medium, while the conjugative metabolite 1-phenanthryl-β-D-glucopyranose was detected in the medium and in the cells. Transcriptome analysis resulted in 870 upregulated and 2,288 downregulated transcripts on PAHs, in comparison to glucose. Genomic mining of 61 available yeast genomes showed a widespread distribution of 31 xenobiotic degradation pathways in different yeast lineages. Two distributions with similar metabolic capacities included black yeasts and mainly members of the Sporidiobolaceae family (including EXF-1630), respectively. This is the first work describing a metabolic profile and transcriptomic analysis of PAH degradation by yeast.

A Study on Polycyclic Aromatic Hydrocarbon and Heavy Metal Concentrations of Commercial Grilled Meat (Suya) and Smoked Catfish (Clarias gariepinus Burchell, 1822) Fish from South-West, Nigeria

This study was undertaken to assess polycyclic aromatic hydrocarbon (PAH) and heavy metal concentrations of commercial grilled meat (suya) and smoked catfish (Clarias gariepinus Burchell, 1822) from South-West, Nigeria. A total of 100 samples of grilled meat and 100 samples of smoked catfish were collected purposively from five major cities in South-West, Nigeria between July and October, 2019. The samples were analyzed to determine PAH and heavy metal [Lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr), and Arsenic (Ar)] concentrations present in the samples. This study revealed that commercial suya and smoked catfish samples from major cities from South West, Nigeria contained varying concentrations of the following carcinogenic PAHs; Benzo[a]pyrene (B[a]P), Benzo[a]anthracene (B[a]A), Benzo[b]fluoranthene (B[b]FA), Benzo [ghi] perylene (B[ghi]P), and Dibenzo(a,h)anthracene (DB[a,h]A). The concentrations of the PAHs in the samples were very high and above the European Union maximum permissible level of 2.0 µg/kg (0.002 mg/kg) for BaP and 12 µg/kg (0.012 mg/kg) for the sum of 4PAHs (B[a]P + Chr + B[b]F + B[a]A) approved by Commission Regulation (EC) No 1881/2006 of 19 December 2006 as amended by Regulation (EU) No 835/2011 of 19 August 2011 for B[a]P allowed in grilled or smoked meat and fish for human consumption. The high concentrations of carcinogenic PAHs in commercial suya and smoked catfish from major cities in South West, Nigeria above the EU maximum permissible level of 2.0 µg kg−1 may be due to poor process control like high grilling temperature above 100 °C and longer grilling time associated with traditional suya processing and fish smoking in Nigeria. This could have resulted in public health concerns for consumers as carcinogenic PAHs have been linked to cancer. Also, the concentrations of Pb, Cd, Hg, Cr, and Ar in the commercial suya and smoked catfish samples studied were very low below the maximum permissible limits approved by World Health Organization, 2006 for grilled and smoked meat and fish which are Pb (0.3 mg/kg); Cd (0.2 mg/kg), Hg (0.2 mg/kg), and Cr (0.3 mg/kg) and therefore the products may not constitute health risks to consumers.

Molecular characteristics, source contributions, and exposure risks of polycyclic aromatic hydrocarbons in the core city of Central Plains Economic Region, China: Insights from the variation of haze levels

In this study, molecular characteristics, source contributions, and health risks of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 for four haze levels in Zhengzhou, a megacity in central China with severe air pollution problems, have been analyzed. The concentrations of PAHs and PM2.5 on heavy haze (HH) days were 63% and 122% higher than non-haze (NH) days. The occurrence of high PAH concentration was often accompanied by the northwest wind along with adverse meteorological conditions that limit regional dispersion. The source apportionment results indicated that almost all sources contributed more PAH concentration on haze days. In particular, coal combustion and vehicle emissions contributions were almost doubled on HH days. The incremental lifetime cancer risk (ILCR) of PAHs has been assessed. BaP and DahA showed relatively high contributions to ILCR, and 31%–48% of ILCR is due to exposure to PAHs on high HH days.

Characterising the exposure of Australian firefighters to polycyclic aromatic hydrocarbons generated in simulated compartment fires

Firefighters are exposed to a wide variety of chemicals including polycyclic aromatic hydrocarbons (PAHs) while attending fire scenes. The objective of this study was to understand the exposure of firefighters to PAHs when attending simulated compartment fires that consisted of either a diesel pan or particleboard fire. Firefighters remained in the compartment fires for 15min while using standard gear including self contained breathing apparatus (SCBA). Firefighters were able to remove firefighting clothing and shower within 10min of leaving the burn. Air samples were collected from inside the compartment during the fire. Twenty-six (26) firefighters participated in the study providing urine and skin wipe samples collected from the wrist and neck before and after either one of the burn types. The concentrations of PAHs were measured in skin wipes and air samples, while concentrations of monohydroxy metabolites of PAHs (OH-PAHs) were measured in urine. The concentrations of all PAHs were significantly higher (p<0.05) in the smoke layer of particleboard fires than in diesel pan fires. Correspondingly, the level of PAHs deposited on the wrists and necks of participants attending the particleboard fires was higher than those attending diesel pan fires. Urine samples from participants who attended diesel pan fires showed no significant difference (p>0.05) in the concentration of all OH-PAHs between pre-burn and post-burn. Samples from participants who attended particleboard fires, showed no significant difference (p>0.05) between 1-hydroxypyrene (1-OH-PYR) concentrations in urine pre- and post-burn. However, median concentrations of hydroxynaphthalenes (OH-NAPs), hydroxyfluorenes (OH-FLUs) and hydroxyphenanthrenes (OH-PHEs) increased significantly from 5.2, 0.44 and 0.88μgg-1 creatinine pre-burn to 12, 1.4 and 1.2μgg-1 creatinine post-burn, respectively. This suggests that in compartment burns with high concentrations of PAHs in the smoke layer, such as those created by the particleboard fires, exposure to PAHs can be observed though urinary OH-PAH metabolites. Overall, concentrations of urinary OH-PAHs were relatively low considering the potential exposure in these burns. This suggests protective equipment in combination with rapid removal of firefighting ensembles and showering are relatively effective in controlling exposure.

Coupled geophysics and geochemistry to record recent coastal changes of contaminated sites of the Bagnoli industrial area, Southern Italy

The paper shows the results of a geochemical - geophysical survey on the decommissioned industrial area of Bagnoli (Naples, southern Italy). Analyses of 15 priority congeners of Polycyclic Aromatic Hydrocarbons (PAHs) were carried out on 21 sediment cores, collected on the beaches surrounding the old iron and steel industrial plant that was active over the last century.Anomalous high concentrations of PAHs were detected in this area, up to 87,000 μg g−1 d.w. In particular, most congeners were embedded inside a mainly sandy layer, characterized by a dark colour and high resistivity values. The joined use of Electrical Resistivity Tomography, chemical data and direct observation of cores allowed a volumetric estimation of the polluted layer corresponding to 20,200 m3. A total of 24,100 m3 of less polluted materials cover the dark, highly polluted layer. In addition, the geophysical-environmental approach helped to disentangle the deep interactions between the beach area, coastal changes and fluid vents. The actual coastal morphology is the result of historical, anthropic-driven rapid evolution that we reconstructed by using available historical images. The achieved results underline a crucial role played by combining geophysical and geochemical methodologies for a deeper and systematic understanding of anthropogenic impacts in coastal systems affected by multiple and combined stressors.

Characterizing the Variation of Dissolvable PAHs in Receiving Water in a Reclaimed Water Irrigation Region

Long-term wastewater and reclaimed water irrigation systems constitute the major processes in local water circulation, which concomitantly introduce plenty of undesirable substances that can threaten water quality, ecosystem functions and human health. At the Southeast Reclaimed Water Irrigation Region (SRWIR) of Beijing, wastewater irrigation was adopted from 1969 to 2002, and second-treated effluents (reclaimed water) has been used thereafter. Polycyclic aromatic hydrocarbons (PAHs) were the most ubiquitously detected contaminant in wastewater and reclaimed water and are reported to be carcinogenic. Hence, we measured the concentrations of dissolved sixteen United States Environmental Protection Agency (USEPA) priority PAHs in surface water and groundwater at the SRWIR to characterize their spatial and temporal variations, and to clarify the role of reclaimed water to natural water. The concentration of 16 individual PAHs in reclaimed water, rivers and groundwater varied from 339.4 to 636.2 ng/L, 359.1 to 3,435.0 ng/L and 216.5 to 488,205.2 ng/L, respectively. The lower aromatic rings of PAHs prevailed in aquatic environments rather than the higher ones. Thereinto, naphthalene was the predominant isomer within the highest concentration reached to 486,600 µg/L. The groundwater samples had higher PAHs concentrations at Tongzhou district which attributed to the higher vulnerability of aquifer. Additionally, strong correlations between PAHs and total nitrogen, nitrate, dissolved oxygen and electrical conductivity suggested those potential factors affecting the photo degradation and/or biodegradation of PAHs. The relationship identified between PAHs concentrations and physical and chemical indices would help us to enhance the understanding migration and transformation of PAHs spatially and temporally, enable us to assess the potential risks of the environmental pollutants to aquatic organisms and human water supplies.