Polycyclic aromatic hydrocarbons with molecular weight 302 in PM 2.5 at two industrial sites in South China

Daytime and nighttime PM(2.5) samples were collected between August 5 and 16, 2009 and between January 24 and February 4, 2010 in an industrial complex site (site A) and an electronic waste recycling site (site B) to determine the seasonal and diurnal variations of 19 individual polycyclic aromatic hydrocarbons (PAHs) with molecular weight 302 (MW302) including four highly carcinogenic dibenzopyrene (DBP) isomers dibenzo[a,l]pyrene (DBalP), dibenzo[a,e]pyrene (DBaeP), dibenzo[a,i]pyrene (DBaiP), and dibenzo[a,h]pyrene (DBahP). This is the first report on DBP isomers in air particles from South China. The total concentration of PAH MW302 isomers ranged from 1.65 to 3.60 ng m(-3) in summer and 3.82 to 9.81 ng m(-3) in winter. The strongest peaks in the chromatograms of the MW302 isomers were naphtha[2,1-a]pyrene (N21aP), dibenzo[j,l]fluoranthene (DBjlF), naphtha[1,2-b]fluoranthene (N12bF), naphtha[1,2-k]fluoranthene (N12kF) and dibenzo[a,e]fluoranthene (DBaeF), constituting 52.0 to 55.4% of the total MW302 isomers. All the MW302 isomers showed notable seasonal variations. Most of the MW302 isomers in site B showed distinctive diurnal variations with higher concentrations occurring in the night. Taking into account both concentration and potency equivalence factors (PEFs), the strongest carcinogen in the analyzed samples was DBaiP, and the ratios of sum carcinogenic potency of four highly carcinogenic DBP isomers to benzo[a]pyrene (BaP) was about 0.94 in winter to 1.89 in summer, indicating the importance of DBP isomers for the risk assessment. Health risk assessment indicated that on average, 1 in 100 000 residents in the two industrial sites may have an increased risk of cancer due to PAH exposure.     

Determination of Polycyclic Aromatic Hydrocarbons in Rougan, a Traditional Chinese Barbecued Food, by Capillary Gas Chromatography

Several polycyclic aromatic hydrocarbons (PAHs), including those which are carcinogenic, have been detected in rougan, a traditional Chinese barbecued pork dish. The food samples were cleaned up by caustic digestion, solvent extraction, liquid-liquid partition, and column chromatography. The determination was carried out using capillary gas-chromatography with a flame ionization detector. A 25-m HP-1 capillary column was used. Fluorene, phenanthrene, anthracene, benzo[a]anthracene, chrysene and benzo[k]fluoranthene were detected in three of the five samples within the range of 3-17 ng/g. Fluoranthene and pyrene were detected in only two of the samples at similar levels. Two potent carcinogenic compounds, benzo[a]pyrene and benzo[b,j,k]fluoranthene, were not detected in any of the samples. No detectable PAHs have been found in meat cooked without the direct contact of food with flame and smoke. In barbecuing over an open charcoal fire, animal fat and juices dripping onto the open fire probably enhanced the formation of PAHs.     

Distribution of polycyclic aromatic hydrocarbons in the atmosphere of Hong Kong

This paper reports the monitoring results of eleven polycyclic aromatic hydrocarbons (PAHs), four to six-ring, at two urban sites-Central & Western (CW) and Tsuen Wan (TW) in Hong Kong from January to December 2000; and the findings of a study conducted in 2001 of the partitioning of the gaseous and particulate phases of PAHs. The sum of the eleven PAHs under study (sigmaPAHs) was found to range from 6.46 to 38.8 ng m(-3). The annual mean levels at 12.2 ng m(-3) and 15.8 ng m(-3) for CW and TW respectively are comparable to those recorded for the previous two years and are also within the reported ranges for other metropolitan cities in the Asia Pacific region. Amongst the selected eleven PAHs, fluoranthene and pyrene were the two most abundant found in the urban atmosphere of Hong Kong during the study period accounting for approximately 80%, of the total PAHs. The ratios of benzo(a)pyrene to benzo(g,h,i)perylene (BaP/BghiP) and indeno(1,2,3-cd)pyrene to benzo(g,h,i)perylene (IDP/BghiP) indicate that diesel and gasoline vehicular exhausts were the predominant local emission sources of PAHs. Seasonal variations with high winter to summer ratios for each of the individual PAHs (CW: 1.6-16.7 and TW: 0.82-8.2) and for sigmaPAHs (CW: 1.9 and TW: 1.8) and a spatial variation of BaP amongst the air monitoring stations are noted. Results of correlation studies illustrate that local meteorological conditions such as ambient temperature, solar radiation, wind speed and wind direction have significant impact on the concentrations of atmospheric PAHs accounting for the observed seasonal variations. A snapshot comparison of the concentrations of PAHs at four sites including a roadside site, a rural site and the two regular urban sites CW and TW was also performed using the profiles of PAHs recorded on two particulate episode days in March 2000.     

Soil pollution by PAHs in urban soils: a comparison of three European cities

The purpose of this study was to determine the degree of contamination with polycyclic aromatic hydrocarbons (PAHs) in samples of urban soil from three European cities: Glasgow (UK), Torino (Italy) and Ljubljana (Slovenia). Fifteen PAHs (naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) were measured in urban soil samples, using harmonised sampling, sample extraction and analyte quantification methods. Although the mean concentration of each PAH in urban soils of each city showed a wide range of values, high levels of contamination were only evident in Glasgow, where the sum of concentrations of 15 PAHs was in the range 1487-51,822 microg kg(-1), cf. ranges in the other two cities were about ten-fold lower (89.5-4488 microg kg(-1)). The three predominant PAHs were phenanthrene, fluoranthene and pyrene, with the sum of these compounds about 40% of the total PAH content. These data, together with some special molecular indices based on ratios of selected PAHs, suggest pyrogenic origins, especially motor vehicle exhausts, to be the major sources of PAHs in urban soils of the three cities. The largest concentrations for PAHs were often found in sites close to the historic quarters of the cities. Overall, the different climatic conditions, the organic carbon contents of soil, and the source apportionment were the dominant factors affecting accumulation of PAHs in soil.     

Polycyclic aromatic hydrocarbons in Dalian soils: distribution and toxicity assessment

Concentrations of 15 polycyclic aromatic hydrocarbons (PAHs) were measured in surface soils collected from Dalian, China, for examination of distributions and composition profiles and their potential toxicity. The sum of 15 PAHs (SigmaPAHs) ranged from 190 to 8595 ng g(-1) dry weight, and showed an apparent urban-suburban-rural gradient in both SigmaPAHs and composition profiles. Using hierarchical cluster analysis (HCA), the sampling sites were grouped into four clusters corresponding to traffic area, park/residential area, suburban and rural areas. The ratios of naphthalene (Nap) and fluorene (Fl) versus fluoranthene (Flu), pyrene (Pyr) and indeno(1,2,3-cd)pyrene (InP) in the four clusters provided evidence of local distillation. The diagnostic ratios indicated the prevalent PAH sources were petroleum combustion and coal combustion in Dalian, and a cross plot of diagnostic ratios distinguished the urban samples from suburban and rural ones. Toxic potency assessment of soil PAHs presented a good relationship with benzo(a)pyrene (BaP) levels, toxic equivalent concentrations based on BaP (TEQ(BaP)) and dioxin-like toxic equivalent concentrations (TEQ(TCDD)). The study highlights that BaP is a good indicator for assessing the potential toxicity of PAHs, and presents a promising toxicity assessment method for soil PAHs.     

Contamination, source identification, and risk assessment of polycyclic aromatic hydrocarbons in agricultural soil of Shanghai, China

The level, distribution, compositional pattern, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in agricultural soil of Shanghai were investigated. The concentrations ranged from 140.7 to 2,370.8 μg kg(?-1) for 21 PAHs and from 92.2 to 2,062.7 μg kg(?-1) for 16 priority PAHs, respectively. The higher level of PAHs was mainly distributed in the south and west of Shanghai region, and the lower concentration was found in Chongming Island. Generally, the composition pattern of PAHs was characterized with high molecular weight PAHs, the seven possible carcinogenic PAHs accounted for 4.8-50.8% of the total PAHs, and fluoranthene, pyrene, and benzo[b]fluoranthene were the most dominant components in soil samples. The correlation analysis suggested that low molecular weight PAHs and high molecular weight PAHs were originated from different sources and further corroborated that total organic carbon was a key soil property affecting the fate of persistent organic pollutants in the environment. The isomer ratios and principal component analysis indicated that PAHs in the investigated areas were derived primarily from combustion of biomass, coal, and petroleum. Compared to the soil quality standards of the Netherlands, all the target PAHs (except Ant) in most samples exceeded their target values. The Nemerow composite index based on the same soil quality standard showed that 69.4% of the soil samples were heavily polluted. The total BaP(eq) of ten Dutch target PAHs in 72% soil samples were higher than the reference total carcinogenic potency. Therefore, the agricultural soil in Shanghai is suffering from serious PAHs contamination.     

Non-occupational exposure to silica dust in vicinity of slate pencil industry, India

Biomonitoring of polycyclic aromatic hydrocarbons (PAHs) in the leaves of Calotropis gigantea R.Br. were performed at seven sites in the surrounding areas of a Thermal Power Plant (TPP), using the gas chromatography and mass spectrometry technique. The primary objective of the study was to monitor the degree of PAHs load in the nearby sites around TPP compared to distant sites. Total PAH (SigmaPAH) concentrations in the leaves ranged from 372.18 (at control site 7) to 4362.35 ng g(-1) d.w. (at highest polluted site 4). The concentration factors ranged from 2.65 to 11.72 for the sites located at 1 km to the point source and 1.0 to 7.08 for distant sites. The share of carcinogenic PAHs to the total PAHs differed with the site, ranging from 10.76% to 26.92%. The sites located closer to TPP have shown higher concentrations of medium and high molecular weight PAHs, which decreased gradually with the distance from the source. The total PAH burden at control site was dominated by the low and medium molecular weight PAHs compounds viz., naphthalene, acenaphthylene, acenaphthene, phenanthrene, fluoranthene, pyrene, chrysene, coronene., whilst at other sites medium and high PAHs viz., fluoranthene, pyrene, benzo (a) anthracene, chrysene, benzo (b) fluoranthene, benzo (e) pyrene and coronene showed the highest values. These results support the biomonitoring ability of Calotropis gigantea R.Br. leaves to monitor PAHs contamination.     

Analysis of polycyclic aromatic hydrocarbons in the atmospheric particulate: focused microwaves for a faster extraction method

In this paper, improvements obtained by using focused microwaves for extraction, in the analysis of polycyclic aromatic hydrocarbons (PAHs) adsorbed on particulate matter, are discussed. The method was tested on the following PAHs, which are considered to be among the most harmful with regard to carcinogenicity: benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene. The extraction of PAHs and concentration of the sample can be performed in 3 h with a recovery of at least 70% and a maximum standard deviation of 4%. These steps are followed by clean-up on a SPE (solid-phase extraction) cartridge and analysis by GC-MS. Real samples collected in the urban area of Bari were analysed according to the proposed procedure.     

PAHs in the urban air of Sarajevo: levels,sources, day/night variation,and human inhalation risk

Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants derived from pyrolysis and pyrosynthesis processes. Industrial activity, motor vehicle emission, and domestic combustion are the main sources of PAHs in the urban atmosphere. In this work, samples collected during the day and night in the urban area of Sarajevo are analyzed separately for gaseous and particle-bound PAHs; the possible origin of PAHs at the receptor site was suggested using different methods applied to the solid phase and to the total PAHs (gaseous + particulate phase). Finally, the risk level in Sarajevo associated to the carcinogenic character of the studied PAHs has been assessed. The result of this study suggests that (a) the total PAH concentrations were higher than those reported in other European cities; (b) the PAH daytime concentrations are higher than nocturnal concentrations: the sum of the PAH day/night ratios is 1.52 (gas) and 1.45 (particle phase); (c) stationary combustion and traffic were suggested to be the main sources of PAHs; (d) the average particle-bound benzo(a)pyrene (BaP) concentration (5.4 ng/m³) is higher than EU target annual value (1 ng/m³); and (e) PAH cancer risk exceeds the carcinogenic benchmark level recommended by the EPA mainly due to BaP during both the day and night periods.     

广东省南海市主干道气溶胶中多环芳烃(PAHs)的研究

气溶胶采样点位于广东省南海市桂江路边缘及两侧 ,采集时间为 2 4 h,连续采集三天。使用仪器为国产大体积采样器。同时在公园内设点采样 ,以作背景研究。样品经超声波抽提和层析柱分离得到正构烷烃、芳烃 (AHs)和极性组分等三种有机组分。对 PAHs进行 GC MS分析 ,气溶胶中具有较高含量的芴、菲、蒽、荧蒽、芘、苯并 [a]蒽、、苯并 [b]荧蒽、苯并 [k]荧蒽、苯并 [a]芘、茚并 [1 ,2 ,3-cd]芘、二苯并 [a,h]蒽、苯并 [g,h,i]等。通过 TSP研究认为 ,主干道的机动车排放和扬尘是气溶胶的主要来源 ,气候改变也是 TSP变化的另一重要因素。     

灌河口海域沉积物中PAHs的垂直分布及生态危害研究

2011年4月通过GC-MS检测和210Pb测年对灌河口海域沉积物(GHES)中的PAHs进行了分析,柱状沉积物中21种PAHs总浓度为21.0~209.0 ng/g,均值为88.1 ng/g,7种致癌PAHs浓度为7.0~90.0 ng/g,其中致癌剂苯并[a]芘浓度为ND~2.0 ng/g。PAHs浓度与沉积物中有机质含量呈低度正相关,与p H无明显相关性。源解析表明,近50年来GHES中的PAHs大部分来自煤和生物质燃烧。近50年来,总PAHs和16种优控PAHs浓度在波动中升高;近年来苊、苊烯、苯并[b]荧蒽、荧蒽、茚并[1,2,3-cd]芘的浓度增高,需查明来源。生态风险评价表明,GHES中以芴为主的负面生物毒性效应会偶尔发生。芴、苯并[b]荧蒽、苯并[k]荧蒽的浓度介于临界与偶然效应浓度值之间,应尽量减少对该海域沉积物的搅动,防止污染物再悬浮导致水体的二次污染。     

焦化废水中多环芳烃的成分谱及污染特征

液-液萃取-高效液相色谱法分析了焦化废水中EPA优先控制的16种多环芳烃含量,总结出其成分谱及污染特征。结果表明:16种多环芳烃在焦化废水中浓度差异较大,主要以在水中溶解度较大的萘、苊、芴、菲、荧蒽、芘为主。其中萘对多环芳烃总量的贡献最大,占总量的36.70%~86.78%。焦化企业排放废水中6种多环芳烃的总量无超标现象,苯并[a]芘单体超标较普遍。     

Health risk assessment of occupational exposure to particulate-phase polycyclic aromatic hydrocarbons associated with Chinese, Malay and Indian cooking

Food cooking using liquefied petroleum gas (LPG) has received considerable attention in recent years since it is an important source of particulate air pollution in indoor environments for non-smokers. Exposure to organic compounds such as polycyclic aromatic hydrocarbons (PAHs) contained in particles is of particular health concern since some of these compounds are suspected carcinogens. It is therefore necessary to chemically characterize the airborne particles emitted from gas cooking to assess their possible health impacts. In this work, the levels of fine particulate matter (PM(2.5)) and 16 priority PAHs were determined in three different ethnic commercial kitchens, specifically Chinese, Malay and Indian food stalls, where distinctive cooking methods were employed. The mass concentrations of PM(2.5) and PAHs, and the fraction of PAHs in PM(2.5) were the highest at the Malay stall (245.3 microg m(-3), 609.0 ng m(-3), and 0.25%, respectively), followed by the Chinese stall (201.6 microg m(-3), 141.0 ng m(-3), and 0.07%), and the Indian stall (186.9 microg m(-3), 37.9 ng m(-3), and 0.02%). This difference in the levels of particulate pollution among the three stalls may be attributed to the different cooking methods employed at the food stalls, the amount of food cooked, and the cooking time, although the most sensitive parameter appears to be the predominant cooking method used. Frying processes, especially deep-frying, produce more air pollutants, possibly due to the high oil temperatures used in such operations. Furthermore, it is found that frying, be it deep-frying at the Malay stall or stir-frying at the Chinese stall, gave rise to an abundance of higher molecular weight PAHs such as benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene whereas low-temperature cooking, such as simmering at the Indian stall, has a higher concentration of lower molecular weight PAHs. In addition, the correlation matrices and diagnostic ratios of PAHs were calculated to determine the markers of gas cooking. To evaluate the potential health threat due to inhalation exposure from the indoor particulate pollution, excess lifetime cancer risk (ELCR) was also calculated for an exposed individual. The findings suggest that cooking fumes in the three commercial kitchens pose adverse health effects.     

Sedimentary record of polycyclic aromatic hydrocarbons in a sediment core from a maar lake, Northeast China: evidence in historical atmospheric deposition

A maar lake is an excellent ecosystem to study the atmospheric deposition of pollutants, as its contaminants are primarily by atmospheric deposition. In this study, a sediment core from Sihailongwan Maar Lake, Northeast China, was collected and the historical atmospherically deposited polycyclic aromatic hydrocarbons (PAHs) were analyzed. The concentrations of TPAHs (the sum of the US EPA proposed 16 priority PAHs, excluding naphthalene and pyrene) ranged from 473.9 to 2289 ng g(-1) with a slow increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments. The input rate of TPAHs, especially that of PAH(9) (the sum of fluoranthene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(ah)anthrathene, and benzo(ghi)perylene), correlated well to the Chinese historical socioeconomic data. This indicates that sediment PAHs were mainly derived from human activities and PAH(9) can be regarded as a better indicator of the local socioeconomic development. Source identification suggested that PAHs were originated primarily from mixed sources (e.g., coal and biomass burning and petroleum combustion), except for perylene which was mostly of diagenetic origin. In addition, the down-core PAHs profile clearly illustrated that PAHs sources in Northeast China experienced a transformation from low- and moderate temperature to high-temperature combustion processes, especially after the late 1980s. Additionally, an ecological risk assessment using two redefined biological thresholds (TEQ(ERL) and TEQ(ERM)) indicated that most of the PAHs measured in the present sediment core would not cause an immediate toxic effect; only FLU and PHEN are a potential source of concern for biological impairment.     

Distribution and source of polycyclic aromatic hydrocarbons (PAHs) in the surface soil along main transportation routes in Jiaxing City, China

Polycyclic aromatic hydrocarbons (16 EPA-PAHs) in urban surface soil from Jiaxing City were determined using HPLC. The total concentration of 16 EPA-PAHs was detected from 18.73 to 441.34 pg/g. Individual PAH occupation analysis demonstrates that four-ring PAHs comprise as much as 44.16% and were prevalent in the composition of PAH pollutants. The other components were two-ring PAHs (7.36%), three-ring PAHs (17.28%), five-ring PAHs (16.16%), and six-ring PAHs (15.04%). Source analysis on the characteristic ratios of anthracene(Ane)/[Ane+phenanthrene(Phe)], fluoranthene(Fla)/[Fla+pyrene(Pyr)], and benzo[a]pyrene(Bap)/benzo[g,h,i]perylene(Bgp) reveals that PAH pollutants originated mainly from coal combustion, but vehicular emission as a source was not negligible. All PAHs discussed in the paper have similar source in most sampling sites. The spatial distributions of pollution sources were closely related to geographic location, geographic condition, and living habit of indigenes. A linear relationship between 2-3-ring PAHs, 4-6-ring PAHs, SOM, and ∑PAHs were investigated and significant correlativity were expatiated lastly. It revealed that coefficient between 2-3-ring PAHs and ∑PAHs is 0.56, between 4-6-ring PAHs and ∑PAHs is 0.99, between SOM and ∑PAHs is 0.82.     

Assessment of hydrocarbons concentration in marine fauna due to Tasman Spirit oil spill along the Clifton beach at Karachi coast

On 27 July 2003, Tasman Spirit spilled 31,000 tonnes of crude oil into the sea at the Karachi coast. This disaster badly affected the marine life (Flora and Fauna.) Present research has been proposed to ascertain the level of Polycyclic Aromatic hydrocarbons (PAHs) contamination in different fisheries including Fishes, Crustaceans; Crabs and Shrimps, Mollusks and Echinoderms along with passing time. Heavier components of crude oil such as Polycyclic Aromatic Hydrocarbons (PAHs) appear to cause most damages as these are relatively unreactive and persist in water. High concentrations of toxic PAHs were observed in all the fisheries and shellfishes caught form oil-impacted area. In this study fishes were found most contaminated than shellfishes i.e. summation operator 16 PAH = 1821.24 microg/g and summation operator 1164.34 microg/g, respectively. Naphthalene was found in the range of 0.042-602.23 microg/g. Acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene were detected in the range 0.008-80.03 microg/g, fluoranthene, pyrene, benzo(a)anthracene and chrysene 0.0008-221.32 microg/g, benzo(b) fluoranthene, benzo(k)fluoranthene and benzo(a) pyrene 0.0005-7.71 microg/g, benzo(g,h,i)perylene and indeno(1,2,3-c,d)pyrene 0.02-503.7 microg/g. Dibenzo(a,h)anthracenre was not detected in any specie.     

Gas–particle concentration,distribution, and health risk assessment of polycyclic aromatic hydrocarbons at a traffic area of Giza,Egypt

Atmospheric particulate and gaseous polycyclic aromatic hydrocarbons (PAHs) samples were collected from an urban area in Dokki (Giza) during the summer of 2007 and the winter of 2007–2008. The average concentrations of PAHs were 1,429.74 ng/m³ in the particulate phase, 2,912.56 ng/m³ in the gaseous phase, and 4,342.30 ng/m³ in the particulate + gaseous phases during the period of study. Dokki has high level concentrations of PAH compounds compared with many polluted cities in the world. The concentrations of PAH compounds in the particulate and gaseous phases were higher in the winter and lower in the summer. Total concentrations of PAHs in the particulate phase and gaseous phase were 22.58% and 77.42% in summer and 36.97% and 63.03% in winter of the total (particulate + gaseous) concentrations of PAHs, respectively. The gaseous/particulate ratios of PAHs concentration were 3.43 in summer and 1.71 in winter. Significant negative correlation coefficients were found between the ambient temperature and concentrations of the total PAHs in the particulate and gaseous phases. The distribution of individual PAHs and different categories of PAHs based on aromatic ring number in the particulate and gaseous phases during the summer and winter were nearly similar, indicating similar emission sources of PAHs in both two seasons. Benzo(b)fluoranthene in the particulate phase and naphthalene in the gaseous phase were the most abundant compounds. Diagnostic concentration ratios of PAH compounds indicate that these compounds are emitted mainly from pyrogenic sources, mainly local vehicular exhaust emissions. Health risks associated with the inhalation of individual PAHs in particulate and gaseous phases were assessed on the basis of its benzo(a)pyrene equivalent concentration. Dibenzo(a,h)anthracene and benzo(a)pyrene in the particulate phase and benzo(a)pyrene and benzo(a)anthracene in the gaseous phase were the greatest contributors to the total health risks. The relative mean contributions of the total carcinogenic activity (concentrations) of all PAHs to the total concentrations of PAHs were 29.37% and 25.15% in the particulate phase and 0.76% and 0.92% in the gaseous phase during the summer and winter, respectively. These results suggest that PAHs in the particulate phase in the ambient air of Dokki may pose a potential health risk.     

Assessment of soil screening levels due to ingestion and dermal absorption of chrysene and benzo[k]fluoranthene and appropriate remediation method for Dorson Abad

For years, the Dorson Abad region has been extremely polluted by Tehran Oil Refinery due to leaking from its underground pipelines, storage tanks, and evaporation ponds. To assess the concentrations of hazardous polycyclic aromatic hydrocarbon (PAH) compounds, soil samples were collected from the grounds at and adjacent to a polluted stream located in the study area. The samples were then analyzed, and the results revealed that 12 of the 16 USEPA PAHs were noticeably present in the soil, which, among them, benzo[k]fluoranthene and chrysene had the highest concentrations with averages of 357.17 and 173.38 mg/kg, respectively. A comparison of the obtained concentrations with the soil screening levels indicated that both benzo[k]fluoranthene and chrysene concentrations were substantially higher than EPA screening level values, signifying the necessity of soil remediation for these contaminants in the area. Techniques such as soil washing/flushing, high temperature thermal desorption, and solidification/stabilization were investigated for treatment of the contaminated soil; solidification/stabilization is recommended as an applicable and cost-effective remediation method for Dorson Abad due to the size of the region, relatively low cost of the binder (cement), and low volatility of benzo[k]fluoranthene and chrysene.     

Polycyclic aromatic hydrocarbons in surface sediments from drinking water sources of Taihu Lake, China: sources, partitioning and toxicological risk

Sources, partitioning and toxicological risk of 15 priority polycyclic aromatic hydrocarbons (PAHs) in surface sediments from drinking water sources of Taihu Lake, with an area of 2428 km(2) located in the most developed and populated area of China, were studied, and the results were compared with those in other lakes of China and the USA. Concentrations of the 15 PAHs in sediments ranged from 436.6 to 1334.9 ng g(-1) (dw). Gasoline combustion, coal combustion, diesel combustion from shipping and spillage of petroleum were apportioned to be the main sources of PAHs in this area by principal component analysis, which contributed 35.19%, 26.43%, 25.41% and 12.97% to the PAH sources estimated by further multiple linear regression. Levels of PAHs in sediments were negatively correlated with contents of clay and fine silt (<16 μm), while positively with contents of medium silt, coarse silt and sand (>16 μm). Humin with size larger than 16 μm contained the largest part of the burden of PAHs in sediments, but the specific partitioning domain (bound humic acid, lipid or insoluble residue) depended on properties of organic matter reflected by optical absorbance at 465 and 665 nm. Total toxic benzo[a]pyrene equivalent (TEQ(carc)) of the carcinogenic PAHs in sediments varied from 31.8 to 209.3 ngTEQ(carc) g(-1). Benzo[a]pyrene and dibenzo[a,h]anthracene contributed 45.36 and 25.31% to total TEQ(carc), posing high toxicological risk to this area.     

Occurrence of dissolved PAHs in the Jinsha River (Panzhihua)--upper reaches of the Yangtze River,Southwest China

16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in water samples from the Jinsha River (Panzhihua part), Southwest China. Total dissolved PAH concentrations varied from 21.89 microg l(-1) to 382.8 microg l(-1). It was found that the concentration of PAHs decreased along the flow direction due to the higher density distribution of coal chemical industry in the upstream of our study rivers. The pollution levels in our study area are significantly higher than previously reported values in other waters both in China and other countries. The predominance of benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene was clearly observed in all water samples. On average these two compounds accounted for 98.3% of the total dissolved PAH concentration in water. The results showed the positive correlations among total dissolved PAHs, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene, which suggested that these two predominant PAHs have similar source and environmental behaviors in our study area. When compared with the survey results of organic micropollutants two decades ago, it was found that hydrocarbon pollution both predominated and even increased with the development of coal chemical industry in this area during the past 20 years. The results therefore provide important information on the current contamination status of a key industrial city in China, and points to the need for urgent action to investigate the relationship between the PAH composition and concentration in water from the Jinsha River and the wastewater discharge from coal chemical industry, and to identify the source, transport pathway and fate of PAHs in the area. It should then be necessary to adopt appropriate and instant measures to control the pollution around this area.