Accumulation,Allocation, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Soil-Brassica chinensis System

Farmland soil and leafy vegetables accumulate more polycyclic aromatic hydrocarbons (PAHs) in suburban sites. In this study, 13 sampling areas were selected from vegetable fields in the outskirts of Xi’an, the largest city in northwestern China. The similarity of PAH composition in soil and vegetation was investigated through principal components analysis and redundancy analysis (RDA), rather than discrimination of PAH congeners from various sources. The toxic equivalent quantity of PAHs in soil ranged from 7 to 202 μg/kg d.w., with an average of 41 μg/kg d.w., which exceeded the agricultural/horticultural soil acceptance criteria for New Zealand. However, the cancer risk level posed by combined direct ingestion, dermal contact, inhalation of soil particles, and inhalation of surface soil vapor met the rigorous international criteria (1×10⁻⁶). The concentration of total PAHs was (1052±73) μg/kg d.w. in vegetation (mean±standard error). The cancer risks posed by ingestion of vegetation ranged from 2×10⁻⁵ to 2×10⁻⁴ with an average of 1.66×10⁻⁴, which was higher than international excess lifetime risk limits for carcinogens (1×10⁻⁴). The geochemical indices indicated that the PAHs in soil and vegetables were mainly from vehicle and crude oil combustion. Both the total PAHs in vegetation and bioconcentration factor for total PAHs (the ratio of total PAHs in vegetation to total PAHs in soil) increased with increasing pH as well as decreasing sand in soil. The total variation in distribution of PAHs in vegetation explained by those in soil reached 98% in RDA, which was statistically significant based on Monte Carlo permutation. Common pollution source and notable effects of soil contamination on vegetation would result in highly similar distribution of PAHs in soil and vegetation.     

Estimation of Toxicity Equivalency and Probabilistic Health Risk on Lifetime Daily Intake of Polycyclic Aromatic Hydrocarbons from Urban Residential Soils

In this study, toxicity equivalents and health risks, based on concentration of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban residential soils were estimated for the human population in Gwalior, India. Benzo(a)pyrene total potency equivalents (BaP TPE) were estimated for assessment of human health risk from direct contact with PAH-contaminated soil. Potential risk to contaminated groundwater from leaching of carcinogenic PAHs was assessed by estimating the index of additive cancer risk (IACR). On the basis of lifetime average daily intake of 16 PAHs through ingestion of PAH-contaminated soils, lifetime cancer risk to human adults and children was estimated. The concentration of probable human carcinogenic PAHs in soils accounted for 38% of ∑16PAHs. BaP TPE and index of additive cancer risk (IACR) were lower than guideline values of 0.6 mg kg^?1 and <1, respectively. Estimated lifetime average daily intakes of PAHs via soil ingestion were lower than recommended dose. However, the ILCR for human adults was within acceptable limits recommended by regulatory agencies, but may need action for children in Gwalior, India.     

Polycyclic Aromatic Hydrocarbons in Road-Deposited Sediments and Roadside Soil in Tijuana,Mexico

Road-deposited sediment and roadside soil in the urban area of the city of Tijuana were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs). The ΣPAH concentration for road-deposited sediment (RDS) ranged between 460 and 2027 µg/kg with an average of 933 µg/kg. The ΣPAH concentration in roadside soil was lower than in RDS, with a range between 54 and 1863 µg/kg and a mean value of 308 µg/kg. The diagnostic ratios showed that the PAHs originated mostly from pyrogenic sources such as gasoline and diesel combustion. The results show that PAH concentration in RDS and roadside soils is low when compared with other published studies. The low PAH levels found in this study are possibly related to differences in climate, urban features, and anthropogenic activities conducted in the studied areas. The toxicity equivalent concentrations (TEQ) of PAH calculated were also low in comparison with other studies. This is probably due to the lower concentration of total PAHs and the highly toxic high-molecular-weight PAHs.     

Concentrations,Source and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Soils from Midway Atoll,North Pacific Ocean

This study was designed to determine concentrations of polycyclic aromatic hydrocarbons (PAHs) in soil samples collected from Midway Atoll and evaluate their potential risks to human health. The total concentrations of 16 PAHs ranged from 3.55 to 3200 µg kg⁻¹ with a mean concentration of 198 µg kg⁻¹. Higher molecular weight PAHs (4–6 ring PAHs) dominated the PAH profiles, accounting for 83.3% of total PAH mass. PAH diagnostic ratio analysis indicated that primary sources of PAHs in Midway Atoll could be combustion. The benzo[a]pyrene equivalent concentration (BaP_eq) in most of the study area (86.5%) was less than 40 µg kg⁻¹ BaP_eq and total incremental lifetime cancer risks of PAHs ranged from 1.00×10⁻¹⁰ to 9.20×10⁻⁶ with a median value of 1.24×10⁻⁷, indicating a minor carcinogenic risk of PAHs in Midway Atoll.     

PAH contamination in road dust from a moderate city in North China: The significant role of traffic emission

To investigate the contamination level, distribution, possible source, and human exposure risk of polycyclic aromatic hydrocarbons (PAHs) in the urban traffic environment, 15 PAHs were measured in 34 road dust samples (particle size < 25 μm) collected from three grades of roads and park paths in Xinxiang, China. ΣPAHs concentrations ranged from 311 to 21200 ng g^?1, with a mean of 5890 ng g^?1 and decreased in the following order: main roads (7650 ng g^?1) > collector streets (7410 ng g^?1) > bypasses (2970 ng g^?1) > park paths (1570 ng g^?1), indicating that significant positive correlation existed between PAH contamination and traffic density. PAHs in all samples were dominantly composed of 4-ring PAHs, accounting for 44.8% of the total. Pyrene, fluoranthene, and chrysene were the predominant individual components and accounted for 14.7% (1.2–19.2%), 12.9% (3.3–20.3%), and 11.0% (2.5–18.6%) of ΣPAHs, respectively. The specific isomer ratios indicated that traffic emission was the dominant source of PAHs in road dust. The incremental lifetime cancer risk values showed that cancer risk from exposure to road dust–borne PAHs was acceptable for local residents in Xinxiang.     

DNA damage measured by the single-cell gel electrophoresis (Comet) assay in mammals fed with mussels contaminated by the 'Erika' oil-spill

This research aimed to estimate potential genotoxicity for consumers resulting from the ingestion of seafood contaminated with polycyclic aromatic hydrocarbons (PAHs) released into the marine environment after the 'Erika' shipwreck along the coasts of south Brittany, in France. Mussels (Mytilus sp.) collected from sites on the Atlantic coast that were affected by the oil slick in various degrees, were used to feed rats daily for 2 and 4 weeks. DNA damage was measured by use of the Comet assay in the liver, bone marrow and blood of rats receiving food contaminated with 312 microg of 16PAHs/kg dry weight (d.w.) equivalent to 33.8 microg TEQs (toxic equivalent quantities to benzo(a)pyrene (BaP))/kg d.w. mussels, 569 microg/kg d.w. (83.6 microg TEQs/kg) and 870 microg/kg d.w. (180.7 microg TEQs/kg). A dose-effect-time relationship was observed between the amount of DNA damage in the liver and bone marrow of the rats and the PAH contamination level of the mussels. Genotoxicity increased during the period between 15 and 30 days in rats that received food at the highest two PAH levels. On the other hand, no significant change in liver and bone marrow of rats fed with mussels containing 33.8 microg TEQs/kg d.w. was recorded at 30 days compared with 15 days, indicating efficient DNA repair capacity at low levels of exposure. No signs of genotoxicity were found in peripheral blood. Globally, the observed effects were rather moderate. These results show that oil-contaminated food caused DNA damage in predators, and underline the bioavailability to consumers of pollutants in mussels contaminated with fuel oil. The usefulness of the Comet assay as a sensitive tool in biomonitoring studies analyzing responses of PAH transfer through food webs was also confirmed.     

Polycyclic aromatic hydrocarbons (PAHs) concentration levels,pattern, source identification,and human risk assessment in foliar dust from urban to rural areas in Nanjing,China

Environmental health is an essential component of quality of life in modern societies. Foliar dust contains polycyclic aromatic hydrocarbons (PAHs) that may have harmful effects on human health. The PAHs concentration of foliar dust is useful to assess environmental air pollution. Our results indicate that: (1) the highest levels of PAHs were distributed in urban areas, with a mean of 3430.23 ng·g^?1, lower mean concentrations were found in suburban (2282.12 ng·g^?1), and rural areas (1671.06 ng·g^?1). (2) Diagnostic ratios and principal component analysis were used to identify the sources of PAHs: Gasoline vehicle traffic emissions were the predominant source in urban areas, along with coal and coke combustion. In suburban areas, the main sources were petroleum combustion (especially liquid fossil fuels) and coal combustion. Coal and wood combustion were the primary source of PAHs in foliar dust in rural areas. (3) The incremental lifetime cancer risk (ILCR), estimated based on the results of this study indicate that urban residents were potentially exposed to high cancer risk via both dust ingestion and dermal contact. We conclude that urbanization has significant effects on the PAH concentrations of foliar dust, illustrating the importance of trees in improving air quality in urban areas.     

Distribution,Levels, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Singed Cattle Hide

Human beings are exposed to polycyclic aromatic hydrocarbons (PAHs) from various occupational, environmental, and dietary sources. The study was carried out in the Cape Coast Metropolis of Ghana to assess the levels of PAHs in treated and untreated cattle hide and the associated health risks thereof. Treated cattle hide (wele) is one of the most well-patronized meat products in Ghana. A total of 90, treated (n = 36), untreated (n = 36), and control (n = 18) cattle hide samples were treated and analyzed using a gas chromatography flame ionization detection (GC/FID) technique. The total PAH concentration in the treated cattle hide ranged from 5.9 μg/kg naphthalene to 719.9 μg/kg benzo[b]fluoranthene. The total PAHs in untreated hide ranged from 57.6 μg/kg naphthalene to 19840.9 μg/kg benzo[b]fluoranthene. The amount of PAHs in the control hide, however, ranged from non-detectable for many of the PAHs to 0.5 μg/kg for fluorene. The carcinogenic risk value associated with the consumption of treated hide in children ranged between 1.0 × 10^?3 and 9.4 × 10^?3 whereas that of adults ranged between 1.9 × 10^?4 and 2.1 × 10^?5. This implies that the continuous consumption of heavily burnt cattle hide may not exempt the consumers from all the possible health cases associated with PAHs.     

Pollution,sources, and ecological-health risks of polycyclic aromatic hydrocarbons in coastal waters along coastline of China

Abstract

This study investigated the distribution, sources, and potential risks of polycyclic aromatic hydrocarbons (PAHs) in coastal waters along over 18,000?km of coastline in China. Concentrations of PAHs in coastal waters ranged from 141.99 to 717.72?ng/L. Approximately 84.38% of sampling sites were determined at moderate PAH pollution level. PAHs in coastal waters at most of sampling sites mainly originated from combustion based on characteristic ratios of PAHs. Ecological risks posed by PAHs in coastal waters were evaluated as high level at 59.38% of sampling sites and moderate level at 40.63% of sampling sites although toxic equivalent quotients of PAHs only ranged from 2.86 to 126.52?ng/L benzo[a]pyrene that was not detected at all sampling sites. Maximal cancer risk/hazard quotient of total PAHs in coastal waters for adults and children reached 6.34?×?10^?4/5.85?×?10^?2 and 2.25?×?10^?3/7.72?×?10^?2, respectively. PAHs exerted high cancer risks for children at 31.25% of sampling sites. Health risks posed by PAHs in coastal waters of this study were higher than those of Japan, Belgium, Greece, Italy, Spain, USA, and Australia, but much lower than those of Singapore, Iran, Brazil, and Egypt. These findings indicate that PAH pollution has become a crucial stress affecting the sustainable development of coastal regions.     

Risk Assessment of Aflatoxin B1 from Food Consumption in the Korean General Population

Levels were evaluated of Aflatoxin B₁ (AFB1) exposure through the intake of AFB1-contaminated foods among Koreans. Average daily intake, excess cancer risk, and population risk of AFB1 from food intake were calculated from Koreans with age greater than 20 years. Average daily intake of AFB1 by food ingestion was 0.064 ～ 0.361 ng/kg bw/ day. Excess cancer risk of AFB1 in food with the surface antigen of the hepatitis B-virus negative (HBsAg^?) and positive (HBsAg⁺) population was 5.76 × 10^{? 7}～ 3.25 × 10^{? 6} and 1.47 × 10^{? 5}～ 8.31 × 10^{? 5}, respectively. Application of JECFA's two tentative maximum levels (MLs) (10 μ g/kg and 20 μ g/kg) resulted in the population risk of 0.0009 ～ 0.0075 and 0.0014 ～ 0.0079 cancers/year/100,000 people, respectively, indicating that lower ML does not give a significant reduction of the risk. However, because Korea has a high incidence of HBsAg⁺ individuals, adoption of lower ML may be a reasonable decision to protect a high risk group. This is the first report on the risk assessment of AFB1 in food among the Korean population. Our study will contribute to providing the solid basis of establishing the maximum levels of AFB1 exposure through food ingestion in Korea as well as other countries.     

Concentrations and Health Risk of Polycyclic Aromatic Hydrocarbons in Some Brands of Biscuits in the Nigerian Market

Concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in 40 brands of biscuits in the Nigerian market. The analyses were performed by gas chromatography-flame ionisation detection (GC-FID) after Soxhlet extraction of the sample with hexane/dichloromethane and clean-up of the extract. The concentrations of Σ16 PAHs in these biscuit samples were in the range of 35.7–645.3 μg kg^?1, 75.9–490.7 μg kg^?1, 91.5–537 μg kg^?1, 18.4–522.2 μg kg^?1, 123.5–393.8 μg kg^?1, 167.2–880 μg kg^?1, 136.5–316 μg kg^?1, and 135.5–241.6 μg kg^?1 for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The concentrations of Σ8 carcinogenic PAHs in the samples ranged from not detected (nd)–323.3 μg kg^?1, 15.7–138 μg kg^?1, 9.7–312.9 μg kg^?1, nd–331.7 μg kg^?1, nd–220.9 μg kg^?1, nd–53.3 μg kg^?1, 18.4–56.6 μg kg^?1, and 6.6–170.8 μg kg^?1 for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The margin of exposure (MOE), based on PAH8 as an indicator for the occurrence and effects of PAHs in food, was less than 10,000, the serious health effects value, in 30% and 8% of the brands for the child and adult scenarios, respectively.     

Health Risk Assessment of Lead in the Republic of Korea

The purpose of this study was to estimate the daily exposure to lead due to food ingestion, air inhalation, and soil ingestion in the Republic of Korea's general population, and to evaluate the level of risk associated with the current lead exposure level using the proportional daily dose (3–4 μg/kg body weight/day) corresponding to the Provisional Tolerable Weekly Intake (PTWI) suggested by the Joint FAO/WHO Expert Committee on Food Additives as the toxicological tolerance level. The estimation of the daily exposure to lead via three pathways including food, soil ingestion and air inhalation was conducted as a chronic exposure assessment. For the lead exposure assessment through dietary intake, 1,389 lead residue data for 45 commodities investigated by the Korea Food and Drug Administration during the period 1995–2000 were utilized (KFDA 1996, 1997, 1998). Six hundred seventy-two air monitoring data from 7 major cities during the period 1993–2000 and 4,500 soil residue data at 1,500 sites during the period 1999–2001 were considered for the lead exposure assessment involving air inhalation and soil ingestion, respectively. The total daily exposure to lead was estimated by combining dietary intake, inhaled amount and soil intake corresponding to the typical activity of the general population, which was treated as a group of adults with a body weight of 60 kg. For risk characterization, the daily exposure to lead was compared with the toxicological tolerance level. The level of risk due to lead exposure was calculated using the hazard ratio (HR). The dietary intake of lead was 9.71 × 10_?4 mg/kg/day and the total daily exposure level, including air inhalation and soil ingestion, was 9.97 × 10_?4 mg/kg/day. The exposure contributions of foods, air and soil induced from the percentage of each media to the total daily exposure were 97.4%, 2.1% and 0.5%, respectively. Of the different commodity groups, the highest contribution to the total exposure came from grain, which represented 47.7% of the total. Additional exposure to lead occurs in certain population groups due to the use of tobacco, alcoholic beverages, and the intake of other foods, all factors not considered in this study. Through the comparison of the daily exposure to lead with the tolerance level based on the PTWI, the hazard ratio was estimated as being 0.25–0.33. This value implies that no increase in blood lead level is to be expected in the general population at the current lead exposure levels.     

High urine 1-hydroxypyrene glucuronide concentrations in Linxian,China, an area of high risk for squamous oesophageal cancer

Most squamous cell carcinomas of the oesophagus in low-risk populations are attributable to alcohol and tobacco consumption, but the aetiologic agents in many high-risk populations have yet to be definitively identified. Linxian, China has some of the highest oesophageal cancer rates in the world. Recent studies suggest that an association exists between high-level exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (B[a]P), and the development of oesophageal cancer. The inhabitants of this high-risk region extensively use coal and wood for cooking and heating in unvented stoves, and thus may be exposed to PAHs produced during the incomplete combustion of these fuel sources. High levels of B[a]P were recently detected in staple food samples from Linxian and histopathologic changes that may be associated with PAH exposure have also been identified in oesophagectomy specimens from the region. In an effort to determine whether this high-risk population is exposed to high levels of PAHs, voided urines from non-smokers (n = 22) without occupational exposure were collected and analysed using immunoaffinity chromatography and synchronous fluorescence spectroscopy for 1-hydroxypyrene glucuronide, a PAH metabolite and index biomarker for mixed PAH exposure. The median urine 1-hydroxypyrene glucuronide concentration (2.06 pmol ml^-1) was equivalent to concentrations detected in current smokers. To the authors' knowledge, this represents the first report of elevated urine 1-hydroxpyrene glucuronide concentrations in Linxian, and the first biologic confirmation that the inhabitants of this rural, non-industrial, high oesophageal cancer risk region are exposed to carcinogenic PAHs.     

Enhanced Degradation of a Mixture of Polycyclic Aromatic Hydrocarbons by a Defined Microbial Consortium in a Two-Phase Partitioning Bioreactor

Biological treatment methods are effective at destroying polycyclic aromatic hydrocarbons (PAHs), and some of the highest rates of PAH degradation have been achieved using two-phase-partitioning bioreactors (TPPBs). TPPBs consist of a cell-containing aqueous phase and a biocompatible and immiscible organic phase that partitions toxic and/or recalcitrant substrates to the cells based on their metabolic demand and on maintaining the thermodynamic equilibrium of the system. In this study, the degradation of a 5-component mixture of high and low molecular weight PAHs by a defined microbial consortium of Sphingomonas aromaticivorans B0695 and Sphingomonas paucimobilis EPA505 in a TPPB was examined. The extremely low aqueous solubilities of the high molecular weight (HMW) PAHs significantly reduce their bioavailability to cells, not only in the environment, but in TPPBs as well. That is, in the two-phase system, the originally selected solvent, dodecane, was found to sequester the HMW PAHs from the cells in the aqueous phase due to the inherent high solubility of the hydrophobic compounds in this solvent. To circumvent this limitation, the initial PAH concentrations in dodecane were increased to sufficient levels in the aqueous phase to support degradation: LMW PAHs (naphthalene, phenanthrene) and fluoranthene were degraded completely in 8 h, while the HMW PAHs, pyrene and benzo[a]pyrene, were degraded by 64% and 11%, at rates of 42.9 mg l⁻¹ d⁻¹ and 7.5 mg l⁻¹ d⁻¹, respectively. Silicone oil has superior PAH partitioning abilities compared to dodecane for the HMW PAHs, and was used to improve the extent of degradation for the PAH mixture. Although silicone oil increased the bioavailability of the HMW PAHs and greater extents of biodegradation were observed, the rates of degradation were lower than that obtained in the TPPB employing dodecane.     

Monitoring of level of mean concentration and toxicity equivalence (TEQ) of polychlorinated biphenyls (PCBs) in selected vegetables,beans and grains in khanewal and multan,Pakistan

Contamination of food chain by Polychlorinated biphenyls through use of pesticides, electric and industrial waste poses human health risk. In previous studies, PCB species were stated as endocrine disrupting pollutants and showed toxic health effects like cancerous and noncancerous in animals. The aim of this study was to investigate the levels of PCBs and its toxicity equivalence in food item from plant source to evaluate the health risk in Khanewal and Multan, Pakistan. Samples were collected and processed for further analysis of PCB species through GC/MS after extraction and clean up. The mean concentrations of PCBs ranged as 2.71–151.67 ng/g in beans and grains and 2.30–97.00 ng/g dry weight in vegetables and were lower than 200–3000 ng/g PCBs recommended by FDA tolerance level for all foods. The mean concentrations of two NDL-PCB species detected in all vegetables, beans and grains except S.indicum and T.aestivum were lower than maximum allowable concentration of non-dioxin like PCBs i.e. 40ngg^?1 reported by European Commission. Mean TEQ of sum of 14 PCB species ranged as 1.52–5.91 ng-WHO-TEQg^?1 in vegetables and 1.46–10.04 ng-WHO-TEQg^?1 in beans and grains. The present study concluded that the mean concentrations and mean TEQs of PCB species in most of the vegetables, beans and grains were found safe but due to higher consumption rate of some vegetables and grains, posed the moderate level of risk for human health. This study emphasizes on an implement of the strict rules regarding the use of restricted chemicals to diminish the effluence in food chains. Current research will be useful in up gradation of effective measures to reduce the poisonous contribution of PCB sources and the sustainability of terrestrial ecosystem in the country.     

Contamination,source identification,and risk assessment of polycyclic aromatic hydrocarbons in agricultural soils around a typical coking plant in Shandong,China

Coking is one of the most important emission sources of polycyclic aromatic hydrocarbons (PAHs) in China. Investigation of the contamination, distribution, and sources of PAHs in agricultural soils around Rong Xin coking plant, China, was conducted, and the potential human health risks were addressed. The total concentration of the 16 PAHs (∑₁₆PAHs) on the United States Environmental Protection Agency priority list had a range from 1774 to 4621 µg/kg (mean 3016 µg/kg). Meanwhile, seven carcinogenic PAHs (∑PAH_7c) owned the total concentrations of 684–2105 µg/kg, and they had the benzo[a]pyrene equivalent (BaP_eq) concentrations at 139.616–1672.850 µg/kg. All soil samples were dominated by PAHs with two to four rings. Data analyses for the potential sources of PAHs showed that the PAHs in soils were principally from pyrogenic sources. Ecological risk assessment of soil PAHs showed that the BaP_eq concentrations of ∑PAH_7c accounted for 99% of the total ∑₁₆PAHs, being a major carcinogenic contributors of ∑₁₆PAHs. Higher levels of PAHs and higher total BaP_eq concentrations in this study indicate a potential carcinogenic risk for humans. Therefore, long-term exposure to coking plants may increase the PAH concentrations in the environment and further raise a potential risk to human health.     

Distribution characteristics,sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in sediments from Haizhou Bay,China

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography–mass spectrometry. Twenty samples were collected from the surface sediments of Haizhou Bay in this survey. This research aimed to identify the PAHs' contamination level, composition pattern, pollution sources, and assess the ecological risk of PAHs. The results showed that the sum of PAH concentrations ranged from 116.6 ng g^?1 to 2414.9 ng g^?1 (mean: 662.42 ng g^?1), which is higher than the reported values for different wetlands worldwide. Three- and four-ring PAHs (accounts for more than 70% of the total PAH content) were predominant in the wetland sediment. The PAHs source distribution in the surface sediments were determined using diagnostic ratio and PCA/MLR. Consequently, multiple PAHs sources were found. Of the total PAH, 79.25% was derived from vehicular emission, 20.75% from coal combustion. The effect range low/effect range median (ERL/ERM) values indicated a low toxicity risk level. However, the fluoranthene concentrations exceeded the ERL level, and even the ERM level, in some stations. The mean effects range–median quotient (M-ERM-Q) suggests a low ecological risk for the PAHs in the sediments.     

Polycyclic Aromatic Hydrocarbon Profiles of Some Brands of Canned Fish in the Nigerian Market

Concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) were determined in selected popular brands of canned fish (mackerel, sardine, and tuna) consumed in Nigeria with a view to providing information on the health risk associated with consumption of these products. The concentrations of PAHs were measured by gas chromatography equipped with flame ionization detection (GC-FID) after dichloromethane/hexane extraction and clean-up. The concentrations of Σ16 PAHs in these brands of canned fish varied from 174.6 to 350.8 μg/kg, 187.4 to 592.5 μg/kg, and 204 to 264.6 μg/kg for mackerel, sardine, and tuna, respectively. Benzo(a)pyrene was detected in 48% of the investigated brands at concentrations higher than the maximum tolerable limit of 5 μg/kg. The daily intake of PAHs from the consumption of any brand of these canned fish ranged from not detected (nd) to 54.3 ng BaP/kg bw/day, nd to 56.4 ng PAH2/kg bw/day, nd to 86.4 ng PAH4/kg bw/day, and nd to 153.7 ng PAH8/kg bw/day. The estimated margin of exposure (MOE) values (BaP-MOE, PAH2-MOE, PAH4-MOE, and PAH8-MOE) in a significant proportion of the brands was less than 10,000, which indicates a potential health risk for the consumers of these brands of canned fish.     

Potential Health Risk of Reused Creosote-Treated Old Railway Ties at Recreational Sites in Korea

Old creosote-treated railway ties reused at recreational sites in Korea are potential hazards, due to the presence of harmful substances in creosote, such as polycyclic aromatic hydrocarbons (PAHs). In such sites, PAHs in ties can be leached or emitted, and human exposure might then occur. In this study, the concentrations of 16 PAHs in soil, air, and tie surfaces in old creosote-treated railway ties reused in recreational sites were investigated, and the potential health risk of the ties was evaluated through two exposure scenarios: a recreational scenario (ingestion of and dermal contact with soil and inhalation of soil particles) and a playground scenario (ingestion after contact and dermal contact with ties). For the recreational scenario, the health risks of PAHs were safe; however, for the playground scenario, the carcinogenic risk of ingestion after contact, and dermal contact with benz(a)anthracene and benzo(a)pyrene on the tie surfaces, exceeded the acceptable risk level (10^–6). For the carcinogenic risks of ingestion after contact with ties, the probabilities of cancer development were 8 and 5 in one million people for benz(a)anthracene and benzo(a)pyrene, respectively. The carcinogenic risks for dermal contact with ties were 2.4 × 10^–6 and 1.4 × 10^–6 for benz(a)anthracene and benzo(a)pyrene, respectively.     

Risk assessment of polycyclic aromatic hydrocarbons (PAHs) in sediments from a mixed-use reservoir

Although reservoirs in China are of great significance, very few studies on risk assessment have been reported for reservoirs. This study investigated distribution characteristics, cancer and ecological risks, and source diagnosis of 16 priority polycyclic aromatic hydrocarbons (PAHs) in sediments from Shitou Koumen Reservoir in Jilin Province, China. A total of 12 sediment samples were collected from the reservoir in August (wet season) 2014. Total PAH concentrations in sediment samples ranged from 1294.51 ng/g to 2755.35 ng/g with a mean concentration of 1757.54 ng/g. For individual PAHs, average concentration of Nap was the highest, 800.56 ng/g, while Acy, Fla, BkF, and DahA were undetected in sediment samples. Light PAHs (2–3 rings) accounting for 74.21% was a dominant PAH compositional pattern. Pearson correlation analysis was carried out; results showed that total PAHs was strongly correlated with the highly enriched sedimentary PAHs, and pH was a major factor in controlling PAH distribution. Lifetime cancer risk was employed to assess cancer risk; results indicated that the fish-culturing area was exposed to cancer risk. The molecular diagnostic ratios of isomeric PAHs were applied to identify possible PAH sources; primary PAH sources were identified as oil-related activities, burning agricultural wastes, vehicular emissions, and industrial discharges.