Occurrence and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Urban Residential Soils from National Capital Region,Uttar Pradesh,India

This study aims to investigate the level of priority polycyclic aromatic hydrocarbons (PAHs) and identification of their potential sources in residential soils. During the study, a total 36 soil samples collected from twelve residential locations at Sahibabad-Ghaziabad area of western Uttar Pradesh, India, a constituted part of the National Capital Region of India. Samples extracted using ultrasonication, cleaned with silica and analyzed by diode array detector–high-performance liquid chromatography using acetonitrile/water as mobile phase. The 25th and 75th percentile concentration of ∑PAHs was 264 μg kg^?1 and 584 μg kg^?1, respectively, with mean and median of 445 μg kg^?1 and 421 μg kg^?1. The detection frequency of PAHs in all samples was lower for low molecular weight PAHs (19%) than high molecular weight PAHs (81%). The concentration of seven probable carcinogenic PAHs accounted for 67% of the ∑PAHs. PAHs toxicity potential as benzo(a)pyrene toxicity equivalent ranged between 2.52–253 μg BaP_TEQ kg^?1. Composition profile of PAHs with different aromatic rings and selected diagnostic molecular ratios suggested the local pyrogenic sources of PAHs from vehicular emissions, diesel engines, biomass combustion, gasoline, and coal combustions.     

Polycyclic Aromatic Hydrocarbons in Residential Soils from an Indian City near Power Plants Area and Assessment of Health Risk for Human Population

This article deals with the distribution, composition profiles, and possible sources of sixteen priority polycyclic aromatic hydrocarbons (PAHs) in residential soils from Korba district in Chhattisgarh State, India. Sixteen priority PAHs in soils were analyzed after ultrasonic extraction, silica gel column chromatographic cleanup, and quantitation was performed using HPLC-DAD. The concentrations of ∑16PAHs were within acceptable limits of soil quality guidelines and the study area got classified as weakly contaminated. The concentration of probable human carcinogenic PAHs in soils accounted for 10% of ∑16PAHs. The concentration of Benzo(a)Pyrene (BaP) accounted 1% to total PAHs. Benzo(a)pyrene Toxicity Equivalency (BaP_TEQ) for 16 PAHs was 30 ± 12 μg BaP_TEQ kg^?1. The composition profiles and molecular ratios of PAHs suggested mixed pyrogenic sources of PAHs from combustion of coal, wood, and vehicular exhaust emissions. Human health risk was assessed by calculating the lifetime average daily dose (LADD) and incremental life time cancer risk (ILCR) for human adults and children. Estimated ILCR was within safe limit (10^?6?10^?5), indicating low risk to human population. Potential risk to contaminated ground water from leaching of carcinogenic PAHs was assessed by estimating the Index of Additive Cancer Risk (IACR).     

Determination of Carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs), Aflatoxins,and Nitrosamines in Processed Fish from the Winam Gulf Area of Kenya and Estimated Potential Exposure in Human

PAHs, aflatoxins and nitrosamines were analyzed in fish samples obtained from various markets and locations within the Winam Gulf area and processed by various methods often used in Kenya. The mean concentrations of total PAHs (TPAHs) in the smoked, charcoal-grilled and fresh tilapia muscle samples ranged from 22.27–44.58, 20.36–28.51, and 11.43–16.53 μg/kg wet weight, respectively. The concentrations of individual PAHs decreased in the order smoked>charcoal-grilled>fresh fish. Of the USEPA 16 PAHs, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene, and benzo(g,h,i)perylene were not detected in all samples analyzed. Fluoranthene, acenaphthene, anthracene, phenanthrene, and acenaphthylene were not detected in fresh tilapia muscles but were generated in significant amounts on the samples during smoking and charcoal-grilling. The risk of exposure to human was estimated to be 0.67 μg/day through consumption of tilapia. The TPAHs levels in fresh fish, smoked and grilled tilapia were higher than the maximum allowable concentrations as per the WHO standards. Aflatoxins were found to be generated in sun-dried Dagaa during handling and storage with total mean concentrations ranging from 0.33–1.58 μg/kg wet weight but none were detected in the fresh samples. The daily intake of aflatoxins through consumption of Dagaa was estimated to be 0.0079 μg/day during the rainy season when the drying process is less efficient. None of the nitrosamines were detected in both fresh and the deep-fried tilapia muscle samples (frying temperatures ranging from 110–170°C) after exposure to nitrites and nitrates in water, in concentrations ranging up to 10 μg/L (NO₂^?) and up to 160 μg/L (NO₃^?).     

Priority Polycyclic Aromatic Hydrocarbons (PAHs): Distribution,Possible Sources and Toxicity Equivalency in Urban Drains

Wastewater from urban areas constitutes one of the major sources of pollutants contributed to aquatic ecosystem. This study was carried out to elucidate the occurrence and possible source of US Environmental Protection Agency identified 16 priority polycyclic aromatic hydrocarbons (PAHs) in water and sediments from the urban wastewater drains in Delhi, India. A total 60 samples (water and sediment) collected during year 2011–2012, and analyzed the following USEPA methods. Water and sediment samples were extracted using liquid-liquid and ultrasonication techniques, respectively. Glass column chromatography with activated silica was used for sample extracts clean-up, followed by quantification on HPLC equipped with diode array detector at 254 nm wavelength using mixture of acetonitrule and water as mobile phase. Concentrations of total 16 PAHs (∑16PAHs) in all drain water samples ranged from 0.29–35.22 μg/L (mean ± SD, 10.83 ± 10.66 μg/L), predominated by two- and three -ring PAHs. The ∑16PAHs concentrations in all collected sediments ranged between 220–19321 μg/kg (mean±SD, 5574 ± 6820 μg/kg) dry weights. High molecular weight PAHs (≥4-ring PAHs) were dominant in sediment samples. Benzo(a)pyrene equivalent (BaPeq), a relative carcinogenic potential to the corresponding PAHs to BaP was estimated and presented. A selected number of concentration ratios of specific PAHs compounds were calculated and used to diagnose the possible sources of PAHs contamination. The diagnostic ratios reflected pyrogenic input from gasoline or diesel powered vehicular emissions as the major source of PAHs. The levels of PAHs observed in water and sediments were compared with similar studies undertaken in other regions of the world.     

Polychlorinated Biphenyls in Sediments from Sicilian Coastal Area (Scoglitti) using Automated Soxhlet,GC-MS,and Principal Component Analysis

A methodology for the PAHs and PCBs congener determination in sediment samples has been revised. We determined the distributions of PAHs and PCBs in the superficial sediments of the Scoglitti (Italy) coastal area to provide data for comparison with other marine systems and to hypothesize the sources. Extraction yield, for PCB, was never less than 60% in most cases, while for PAHs, utilizing perdeuterated surrogate standard (benz[a]anthracene-d₁₂ and anthracene-d₁₀) was never less than 72%. The total concentration of the 16 PAHs investigated, expressed as the sum of concentrations, ∑PAHs, varied from 1–5087 μg/kg of dry matrix, while the ∑ PCBs ranged from detection limit to 36 μg/kg of dry matrix. Linear relationships were found between PAHs concentration and organic matter percentages (R² = 0.60) and water content and organic matter percentages (R² = 0.87). Isomeric ratios were used for discriminating between pyrolitic and petroleum origin. The principal component analysis (PCA) has been conduced to discriminate the different sampling sites in internal or external harbor area.     

Residue Levels,Profiles, Emission Source and Daily Intake of Polycyclic Aromatic Hydrocarbons Based on Smoked Fish Consumption,An Egyptian Pilot Study

Residue levels and spectrum of polycyclic aromatic hydrocarbons (PAHs) were determined in smoked fish, and canned smoked fish, collected from grocery shops from Cairo, Giza, Menoufya, and Ismailia governorates, Egypt. Residues of PAHs were monitored using gas liquid chromatography, equipped with a flame ionization detector. The concentrations of ∑13 PAHs in the smoked fish and the canned smoked fish ranged from 36.06–547.1 μg/kg, respectively. Benzo(a)pyrene was not detected in smoked canned fish, while its mean residues in smoked fish amounted to 1.1 μg/kg, corresponding to one fifth of the maximum tolerable limit of 5 μg/kg established by EU. The congeners profile showed that the sources of PAHs in the two brands of smoked fish are mainly petrogenic. Based on smoked fish the daily intake of 13 PAHs and benzo(a)pyrene were 45.59 μg/day and 0.092 μg/day, respectively, while for canned smoked fish the intake was fifteen times lower (3 μg/day), and the intake of benzo(a) pyrene is zero μg/day. Results showed that the consumption of smoked fish would pause some risk to consumers; meanwhile canned smoked fish showed no risk to Egyptian consumers.     

Polycyclic Aromatic Hydrocarbons,Heavy Metals,and Genotoxicity of the Suburban Soils from Guangzhou,China

During the past few decades, urban and suburban developments have grown at unprecedented rates and extents with unknown consequences for ecosystem function. The problem of soil pollution as a result of the accelerating development of Guangzhou in China is becoming great concerns. In the present study, gas chromatograph coupled mass spectrometry (GC-MS), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were employed to determine the 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) and the heavy metals (As, Cr, Cu, Pb, Cd, Hg, and Se) of soils collected from suburban areas of Guangzhou. The genotoxicity of these soils was screened with micronucleus (MN) assay in Vicia faba root cells. The concentrations of the pollutants in the soils were (dried weight): ΣPAHs (230.6–1263 ng·g^?1), As (2282.6–36064 μg·kg^?1), Cr (7109–64699 μg·kg^?1), Cu (7047–56388 μg·kg^?1), Pb (9675.9–93739 μg·kg^?1), Cd (68.5–847.3 μg·kg^?1), Hg (85.4–549.2 μg·kg^?1), and Se (219.2–968 μg·kg^?1), which fell in the moderately polluted range. However, six out of nine soil-exposed groups had a significant increases of MN frequencies observed in the V. faba root cells compared with the negative group (P < 0.05, P < 0.01), indicating that they had potential genotoxic risks. Bringing together the chemical analyses with the biological effects observed in this study, the genotoxic response could at a certain degree be explained by both the soil PAHs and heavy metals. Our results suggested that apart from chemical analysis, bioassays like the MN assay of V. faba root cells should also be included in a battery of tests to assess the eco-environmental risks of urban and/or urbanization in the developing areas on the soils.     

Status of PAHs in Environmental Compartments of South Africa: A Country Report

This article covers the status of PAH concentrations and composition patterns in surface water, air, sediment, and soil samples from South Africa. Despite South Africa being one of the largest economies in Africa, it is only recently that researchers have reported the presence and possible sources of these compounds in various environmental compartments. This article discusses the potential hotspots and possible sources of these compounds. It also compares the total PAH concentrations and percentage composition patterns of the individual PAHs. So far, total concentrations of five PAHs determined in sediment samples from the Johannesburg area, Gauteng Province, gave the highest concentrations ranging from 1233–136,276 μg kg^?1. The total concentration of six PAHs found in runoff water from the Venda region of the Limpopo Province, gave the highest concentration with a range of 28.7–3192.6 μg L^?1. The decreasing order of percentage composition of PAHs in water samples tended to follow 3-ring > 4-ring > 2-ring PAHs. In soil samples the decreasing order of percentage composition followed 4-ring > 3-ring > 5-ring > 2-ring > 6-ring PAHs. The total freely dissolved PAHs followed solubility of the compounds with 2-ring > 3-ring > 4-ring > 5-ring > 6-ring PAHs. Some of the identified sources of PAHs using molecular ratios include petrogenic emissions such as from petroleum combustion from vehicles and pyrolytic sources such as coal combustion by coal powered power stations, as well as iron and steel production industries. Oil spills were also identified as major PAH contributor in runoff water from the Venda region of the Limpopo Province.     

The Effect of Local Cooking Methods on Polycyclic Aromatic Hydrocarbons (PAHs) Contents in Beef,Goat Meat,and Pork as Potential Sources of Human Exposure in Kisumu City,Kenya

Roasted meat is known to be a major source of human exposure to PAHs. The contribution of direct-heat charcoal-roasted, electric- oven grilled, and shallow-pan fried meat to human exposure in Kisumu City was not known although the three modes of cooking meat are very prevalent. This study analyzed the concentrations of the PAHs in raw beef, goat meat, and pork, investigated the effect of direct-heat charcoal roasting, electric-oven grilling, and shallow-pan frying on these concentrations, and compared their concentration levels with international standards for foods in order to assess the potential risks to consumers. Samples were taken from three popular meat-roasting hotels within Kisumu City, Kenya. Extraction of PAHs was done using liquid-liquid partition after saponification with alcoholic potassium hydroxide followed by clean-up on a silica gel column and final analysis by gas chromatography-mass spectrometry (GC-MS). Roasting and shallow-pan frying introduced new PAHs and significantly (P ≤ 0.05) increased the concentrations of those existing in raw meat. Direct-heat charcoal roast beef had 5 new PAHs and a total mean PAH content of 17.88 μg/kg, compared with a mean of 1.39 μg/kg for raw beef, with the potent dibenz(a,h)anthracene also being detected. Direct-heat charcoal roasted goat meat had three new PAHs and a total mean PAH content of 4.77 μg/kg, compared with a mean of 2.13 μg/kg in raw meat, with the potent benzo(a)pyrene concentration being 8.84% of the total mean PAH. Fried pork had 7 new PAHs and a total mean PAH content of 3.47 μg/kg, compared with a mean total of 0.17 μg/kg, detected in the raw meat. Roast beef had the highest individual PAH concentration (5.03 μg/kg) and highest total PAHs concentration (17.88 μg/kg), both being higher than acceptable EU limits. The PAHs from local raw and cooked meat were characterized and quantified for the first time in Kisumu City and the study therefore provided the needed baseline data on PAHs in raw and cooked meat.     

Urban Stream Vulnerability Toward PAHs and n-Alkanes and Their Source Identification

Monjolinho River is an important water body located in the central urban region of São Paulo State in southeast Brazil. The present work reports a 4-year study related to spatio-temporal distribution and source identification of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in surface water and sediment samples of Monjolinho River. A total of 25 sampling campaigns for water, and 10 sampling campaigns for sediment collection, were performed from 2011 to 2014. In sediment samples, total PAHs were found in the range of 2.25 µg kg^?1–26,253.87 µg kg^?1, while n-alkane concentrations ranged from 0.01 to 165.64 µg kg^?1. Total PAHs' concentration in surface water was in the range of 0.17–1,348.35 ng L^?1, while n-alkanes were detected in the range of 6.17–316.15 µg L^?1. Principal component analysis was used as a statistical tool for summarizing and interpreting a huge quantity of data. It was observed that concentrations of contaminants increased along the river course in urban zone. Distribution indexes were calculated to identify possible sources of carbon pool that pointed towards petrogenic, pyrogenic, and biogenic sources. The overall concentrations of PAHs and n-alkanes were low compared to many previous studies done elsewhere and were mostly below the threshold effects level except in very few occasional cases, while probable effect level was violated in 1 sample during 4 years. Although adverse impacts are unexpected due to overall low contaminant concentrations, unexpected industrial, and sewage discharges make it risky for safer use as a drinking water resource, especially in dry conditions.     

Concentrations and Source Identification of Polycyclic Aromatic Hydrocarbons (PAHs) in Mangrove Sediments from North of Persian Gulf

The concentrations of 16 Environmental Protection Agency (EPA) priority polyaromatic hydrocarbons (PAHs) were quantified in surface sediments from Hormozgan Province mangroves, south of Iran in dry and wet seasons. Sampling stations were selected in Laft and Khamir mangroves with international importance. Polyaromatic hydrocarbons varied from 75.24 ± 11.24 to 581.94 ± 637.39 ng/g dry weight basis. Pollution sources and their contribution for polyaromatic hydrocarbons pollution in sediments of Hormozgan mangroves were appointed based on molecular ratios and statistical methods, including principal components analysis (PCA) and multiple linear regression/principal components analysis (PCA/MLR) tests. Both of pyrogenic and petrogenic sources contributed in detected concentrations of PAHs. Contribution percentages of pyrogenic and petrogenic origins were estimated at 73.20 and 26.79%, respectively. Temporal variations showed that sediments contained higher levels of ∑PAHs in wet season than dry time. However, the mean detected ∑PAHs was lower than international quality guidelines; the high concentration of PAHs was found in Laft mangrove, suggesting the presence of PAH polluted localized area.     

Evaluation of Polycyclic Aromatic Hydrocarbons Contamination in the Sediments of the Johor Strait,Peninsular Malaysia

In May 2013, sediment samples were collected from five stations in the Straits of Johor, near the southern tip of Peninsular Malaysia, in order to evaluate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 United States Environmental Protection Agency PAHs varied from 650.5 to 1441.2 ng g ^?1 dry weight (dw) with a mean value of 985.5 ng g ^?1 dw. PAHs can be classified as moderate level pollution in the collected samples. When comparing PAHs in this study with that of the sediment quality guidelines (SQGs), it was found that the total PAHs, low molecular weight (LMW), and high molecular weight (HMW) PAHs might incur minimal adverse biological effects. The diagnostic ratios of individual PAHs indicated both petrogenic and pyrogenic origins with predominantly pyrogenic sources, the findings of which are further supported by the results from principal component analysis (PCA). The PCA results reveal contributions of 44.44%, 32.3%, and 18.96% for traffic-related, coal combustion, and petroleum-related products, respectively. These findings indicate that the effective monitoring and significant improvement resulting from the implementation of environmental regulations in Malaysia might have caused a shift in the source of petroleum hydrocarbons in the Straits of Johor's aquatic ecosystems from petrogenic to pyrogenic origins.     

Levels of Some Persistent Organic Pollutants (PCBs and PAHs) in Jordanian Oil Shale Ash after Direct Heating at Different Temperature Ranges

The levels of 13 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs) were studied in oil shale ash samples gathered after heating oil shale samples collected from major deposit sites in Jordan. All analyses were carried out using GC/MS instrument. The results showed that the total concentration of the studied polycyclic aromatic hydrocarbon (PAHs) was the highest (75.99–317.53 μg /kg) at the lowest temperature range (200–400°C) and it decreased as the temperature increased. For the heating temperature range 400–600°C the concentrations were all decreased to below the limit of quantification while none of the samples contained any of the studied PAHs at the highest temperature range 600–800°C. While all the analyzed samples did not contain any of the studied 13 compounds of PCBs at different temperature ranges.

Recoveries of PAHs and PCBs were found between 82–106% and 91–114%, respectively. Precision of the analytical method for both PAHs and PCBs, calculated as relative standard deviation (RSD), ranged from 0.95–7.08% and 0.78–9.03%, respectively. The limit of detection values for PAHs and PCBs were between 0.006–0.070 μg/kg and 0.149–0.330 μg/kg, respectively.

The total estimated cancer risks of exposure to PAHs in the soil samples were ranged from 9.13 × 10^?7 to 2.15 × 10^?6. By multiplying these numbers of cancer risks of exposure to oil shale ash sample-PAHs by 10⁶, it is possible to determine the maximum theoretical number of cancer cases per million of people. The maximum estimated cancer risks cases determined in this study (2 out of 1 million) are well within the acceptable range of excess cancer risk specified by the US Environmental Protection Agency.     

Indoor Polycyclic Aromatic Hydrocarbon Concentration in Central India

The indoor burning of different materials like fuels, incense, mosquito coil, candles etc. results in generation of polycyclic aromatic hydrocarbons (PAHs) in an uncontrolled manner. The PAH, i.e., Benzo(a)pyrene (BaP) is considered as most toxic or carcinogenic and the toxicity of other PAHs is related to this compound. Therefore, the concentration and emission fluxes of polycyclic aromatic hydrocarbons (PAHs) emitted during burning of commonly used indoor materials, i.e., 15 fuels (i.e., biomass (BM), coal (C), cow dung (CD), kerosene (K)), 4 incense (IS) and mosquito coil (MC) in Raipur district, Chhattisgarh, central India is described. The samples were taken in September 2013 in indoor environments and respective smoke emitted were collected using high volume United State of America (USA) air sampler on quartz fiber filters. The concentration of total 13 PAHs (∑PAH₁₃) (i.e., phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)-pyrene, dibenz(ah)anthracene, benzo(ghi) perylene, indeno1,2,3-(cd)pyrene, and coronene) in particulate matter (PM₁₀) in the indoor air during burning of the fuels, IS and MC materials ranged from 367–92052 ng m^?3, 4089–14047 ng m^?3, and 66–103 ng m^?3 with mean values of 7767 ± 11809 ng m^?3, 9977 ± 4137 ng m^?3, and 74 ± 20 ng m^?3, respectively. The mean concentration of the ∑PAH₁₃ present in indoor environment is much higher than the WHO limit value of 1.0 ng m^?3. The sources and toxicities of PAHs are discussed.     

Distribution and Removal of Polycyclic Aromatic Hydrocarbons in Two Italian Municipal Wastewater Treatment Plants in 2011–2013

PAH (Polycyclic Aromatic Hydrocarbons) analyses were carried out on samples from two Wastewater Treatment Plants (WWTPs) in Lombardy, similar for treatment sequences but fed on different influents: industrial component accounts for 70% at Alto Seveso plant while it is absent in Nosedo plant. Sampling concerned the influent and the effluent from activated sludge reactor and the final effluent after disinfection (ozonation for Alto Seveso and peracetic acid treatment for Nosedo). The concentrations of total PAHs were 5.3 ± 4.0 μg L^?1 and 2.4 ± 1.3 μg L^?1 in Alto Seveso and Nosedo influent, respectively. The lowest molecular weight PAHs had the highest concentrations in both plants; acenaphthene and naphthalene were the most important components in the influent to Alto Seveso and Nosedo WWTPs, respectively. The higher molecular weight compounds had the lowest concentrations and benzo(g,h,i)perylene and dibenzo(a,h)anthracene were never detected. Most of the PAH load entered biological treatment in dissolved form. For both plants PAHs were mostly removed in the biological section (96.5% and 89.5% for Alto Seveso and Nosedo, respectively), while disinfection had a minor role. Peracetic acid (Nosedo) seemed more efficient than ozone (Alto Seveso) in the removal of PAHs (4.18% and 0.89%, respectively). It is now necessary to confirm this result by using the same effluent for the two disinfection treatments.     

The Effect of Polycyclic Aromatic Hydrocarbons on the Structure of Organotrophic Bacteria and Dehydrogenase Activity in Soil

The objective of this article was to determine the structure of microbial communities and the activity of dehydrogenases in soil samples contaminated with four polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, anthracene, and pyrene, in the amount of 0, 1000, 2000, and 4000 mg kg^?1soil DM. Organic substances—cellulose, sucrose, and compost—were added to the samples in the amount of 0 and 9 g kg^?1soil DM. The experiment was performed in a laboratory on samples of loamy sand. Indices of colony development (CD) and eco-physiological diversity (EP) of organotrophic bacteria, soil resistance (RS), and soil resilience (RL) were calculated. Soil contamination with PAHs differentiated the structure of organotrophic bacteria, and the lowest CD and EP values were noted in soil samples containing pyrene. PAHs inhibited the activity of dehydrogenases, and pyrene exerted the most inhibitory effect on enzyme activity. Dehydrogenase activity was determined mainly by the applied PAH dose, the date of analysis and the type of organic substance added to soil. Low RL values indicate that exposure to PAHs induces long-term changes in dehydrogenase activity.     

Distribution,Sources, and Risk of Polycyclic Aromatic Hydrocarbons in the Core Sediments from Baiyangdian Lake,China

The burial characteristics and risks of 16 polycyclic aromatic hydrocarbons (PAHs) in core sediments from Baiyangdian Lake were investigated through gas-chromato graphy/mass spectrometry. The total concentrations of the 16 PAHs ranged from 39.48–1877.75 ng g^?1. The low-molecular-weight PAHs (two- to three-ring PAHs) were the dominant species, contributing 40.10–92.18% to the total PAHs, with a mean of 71.01%. Based on the observed molecular indices and on principal component analysis, the PAHs inputs were initially dominated by biomass and coal combustion, and atmospheric deposition and surface runoff could be the major transport pathways. The contaminated source characteristics, hydrodynamic condition, and sediment textural composition are the key factors affecting the distribution and source of PAHs. By conducting a risk quotient analysis between specific PAH concentrations and their corresponding sediment quality values, the top layer sediments were found to have a potential biological impact and relatively high toxicity. However, such impact should have no impairment. The toxic potency of PAHs in Baiyangdian Lake could be described by using the toxic equivalent of benzo[a]pyrene.     

LONG TERM MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN BLUE MUSSELS (Mytilus edulis) FROM A REMOTE SCOTTISH LOCATION

Farmed mussels have been collected on a monthly basis since 1999 from a remote site on the west coast of Scotland for polycyclic aromatic hydrocarbon (PAHs) analysis with the aim of establishing background concentrations as a benchmark against which to assess any environmental incident. Total PAH (2- to 6-ring parent and alkylated) concentrations ranged from 12.5 to 151.2 μg kg^?1 wet weight. Seasonal trends were evident with concentrations being significantly higher for samples collected between November and March compared to those collected between April and October. By taking the median of medians for each of these time periods two background concentrations are suggested for the total PAH concentrations (2- to 6-ring PAHs parent and alkylated); for April to October: 31.2 μg kg^?1 wet weight and for November to March: 62.9 μg kg^?1 wet weight. Individual PAH concentrations were mainly below the OSPAR Background Assessment Concentrations (BACs), where they are specified, and were only exceeded for the heavier 4- and 5-ring PAHs (fluoranthene, pyrene, benz[a]anthracene and benzo[a]pyrene) in samples collected between November and March. Differences were also seen in the PAH profiles with season. Mussels collected between November and March had a higher proportion of the heavier PAHs compared to mussels collected in the summer and autumn.     

Profiles and Sources of PAHs in Sediments from an Open-Pit Mining Area in the Peruvian Andes

The Peruvian Andes are one of the most productive areas for mining and therefore also one of the most exposed to these sources of pollution. This article reports the characterization of Polycyclic Aromatic Hydrocarbons (PAHs) in sediments of Cerro de Pasco area (Peru) located close to a large open-pit mine and, in recent years, several reports have provided evidence of environmental contamination and related health problems. Investigations were carried out into the fifteen PAHs identified by the US-Environment Protection Agency (US-EPA) as requiring priority monitoring, other non US-EPA listed PAHs and perylene were also investigated in order to obtain further information on their origins. By considering the results of all the analysis, the total PAHs concentration varies from 13–1009 μg/Kg with a mean value of 224 μg/Kg. The concentrations of PAHs found in all 12 stations were lower than the effect range low (ERL). PAHs, in the most of the samples, have origin from high temperature processes. Taking into consideration that perylene concentrations were low, a small quantity of polycyclic hydrocarbons may be originated from biological activity.     

Gas-Particle Partitioning of PAHs In The Urban Air of Dalian,China: Measurements and Assessments

To evaluate the gas-particle partitioning behavior of polycyclic aromatic hydrocarbons (PAHs) in the urban air of Dalian, China, both gas phase and particle phase ambient air were monitored with active high-volume sampler from November 2009 to October 2010. The average total concentration of 16 US EPA priority monitoring PAHs (particle + gas) (∑PAHs) was 112 ng m^?3 and the most abundant PAH was Phenanthrene. ∑PAHs and the gas-particle partitioning coefficients (K _p) of PAHs displayed seasonal variation in the order of winter > autumn > spring > summer. ∑PAHs was much higher during the heating period than non heating period. ∑PAHs in gas phase were all higher than those in particle phase in the four seasons. The PAHs sources identification was attempted using diagnostic ratios. The relationship between the concentration of PAHs in the air and meteorology parameters were analyzed using SPSS packages. The concentrations of PAHs in the air decreased with the increase of ambient temperature, and increased with the increase of atmospheric pressure. The gas-particle distribution was examined through several different approaches such as the relationship of logK _p with the ambient temperature, with the logarithm of the sub-cooled vapor pressure (logP _L ⁰), and the octanol-air partitioning coefficient (logK _oa) of PAHs. The slopes obtained from regressing logK _p vs. logP _L ⁰ was ?0.687～?0.821 in heating periods, which was in the range between ?0.6 and ?1, indicating the partitioning of PAHs to particle phase in the urban air of Dalian was absorption as well as for adsorption mechanism. However, the average slope value was ?0.502 in the non heating periods, which was shallower than -0.60, indicating that the absorption mechanisms contributed more to the partitioning process. The exposure risk of PAHs was evaluated with four methods, the results of which indicated that the quality of the urban air of Dalian was better.