Molecular simulations of benzene and PAH interactions with soot

Molecular mechanics simulations and ab initio calculations were performed to investigate the mechanism of PAH-soot adsorption. Partitioning of benzene, naphthalene, fluorene, phenanthrene, anthracene, pyrene, fluoranthene, benzo[a]anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and benzo[g,h,i]perylene between water and soot was modeled with classical and quantum mechanical calculations in order to determine a method for predicting log(K(d)) values. In both cases, the predicted mechanism of adsorption is interaction of the pi-electrons in the PAH and soot (i.e., pi-pi van der Waals forces). Solvation energies, the energy difference between the solute in the gas phase and in the model aqueous phase, calculated with molecular mechanics did not follow the observed solubilities of the PAHs. Molecular dynamics simulations overestimate the favorability of PAHs in the aqueous phase. Hence, the partitioning between the aqueous phase and soot does not accurately correlate with observed log(K(d)) values. Models of PAH adsorption using structures from molecular mechanics and energies from ab initio calculations do produce water-soot partitioning energies that correlate well with observed log(K(d)) values. The log(K(d)) values for benzene, anthracene, fluorene, and benzo[a]pyrene were predicted based on the correlation between calculated partitioning energies and observed log(K(d)) values. Results presented here suggest that partitioning of PAHs onto soot should depend on the size of the PAH, the planarity of PAH molecule, and the aromaticity of the compound. The methodology developed bythis research can be used to predict PAH K(d) values that have not yet been measured.     

Trophic dilution of polycyclic aromatic hydrocarbons (PAHs) in a marine food web from Bohai Bay, north China

Trophic transfer of polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystems is an important criterion for assessing their ecological risk. This study analyzed 18 PAHs in phytoplankton/seston, zooplankton, five invertebrate species, five fish species, and one seabird species collected from Bohai Bay, and trophic transfer of the PAHs was determined in the food web, of which the length was approximately 4 on the basis of stable nitrogen isotope values. The concentrations of PAHs (2-64.5 ng/g wet weight) in the marine ecosystem were moderate compared with other marine organisms worldwide, and the PAH compositions exhibited species-specific profiles that were related to trophic levels in some organisms. Significant negative relationships were also found between trophic levels and lipid-normalized concentrations for 10 PAH compounds (acenaphthylene, anthracene, fluoranthene, pyrene, chrysene, benz[a]anthracene, benzo[b]fluoranthene + benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, and perylene), and their trophic magnification factors (TMFs) ranged from 0.11 for fluoranthene to 0.45 for acenaphthylene. These results confirm that PAHs undergo trophic dilution in the marine food web, which is likely to be the combined results of low assimilation efficiencies and efficient metabolic transformation at higher trophic levels.     

Polycyclic aromatic hydrocarbons in food samples collected in Barcelona, Spain

This study reports on the concentrations of eight polycyclic aromatic hydrocarbons (PAHs) in food samples collected in the city of Barcelona (Catalonia, Spain) from 2003 to 2004. Food samples included meat products, fish (fresh and smoked), other seafood (cephalopods, crustaceans, and bivalves), vegetable oil, and tea. Concentrations of benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[g,h,i]perylene, benzo[alpha]pyrene, benzo[e]pyrene, dibenz[a,h]anthracene, and indeno[1,2,3-c,d]pyrene were determined by reversed-phase high-performance liquid chromatography with fluorescence detection. PAHs were detected in most tea samples (94%), which had the highest concentration of total PAHs (mean concentration of 59 microg/kg). Other food groups with a high presence of PAHs were bivalves (present in 34% of the samples; mean value of 2.7 microg/kg) and meat products (present in 13% of the samples; mean value of 1.7 microg/kg). The PAHs detected most frequently were benzo[e]pyrene and benzo[b]fluoranthene. No sample had levels above current regulation standards. Nevertheless, the frequent presence of PAHs in bivalves, tea samples, and meat products, together with the fact that dietary sources are the main exposure to these carcinogenic compounds, suggests the need for some monitoring scheme to follow up on these trends.     

Polycyclic aromatic hydrocarbons in foods: human exposure through the diet in Catalonia, Spain

The dietary intake of 16 polycyclic aromatic hydrocarbons (PAHs) (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-c,d]pyrene) by the general population of Catalonia, Spain, was calculated. Concentrations of PAHs in food samples randomly acquired in seven cities of Catalonia from June to August 2000 were measured. Eleven food groups were included in the study. High-performance liquid chromatography was used to analyze PAHs. The dietary intakes of total and carcinogenic PAHs was calculated for five population groups: children, adolescents, male adults, female adults, and seniors. Among the analyzed PAHs, there was a predominance of phenanthrene (16.7 microg/kg) and pyrene (10.7 microg/kg). By food group, the highest levels of total PAHs were detected in cereals (14.5 microg/kg) and in meat and meat products (13.4 microg/kg). The mean estimated dietary intake of the sum of the 16 PAHs was as follows: male adults, 8.4 microg/day; adolescents, 8.2 microg/day; children, 7.4 microg/day; seniors, 6.3 microg/day; female adults, 6.3 microg/day. The calculated daily intake of PAHs would be associated with a 5/106 increase in the risk for the development of cancer in a male adult with a body weight of 70 kg.     

Exposure to polycyclic aromatic hydrocarbons through consumption of edible marine species in Catalonia, Spain

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs; naphthalene, acenaphtylene, acenaphtene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene) were determined by gas chromatography-mass spectrometry in samples of 14 edible marine species (sardine, tuna, anchovy, mackerel, swordfish, salmon, hake, red mullet, sole, cuttlefish, squid, clam, mussel, and shrimp) collected in March and April 2005. These species are widely consumed by the population of Catalonia, Spain. PAH intake was also estimated for eight age and sex groups of this population. Mussel, clam, and shrimp had the highest PAH concentrations (22.4, 21.5, and 15.9 ng/g of fresh weight, respectively). In contrast, sole (2.5 ng/g of fresh weight) and cuttlefish and squid (both 3.0 ng/g of fresh weight) had the lowest mean concentrations. The highest PAH intake was found in women and girls (5.3 and 5.2 ng/kg/day, respectively), but female adolescents and female seniors had the lowest PAH intakes (3.3 ng/kg/day in both groups). The intake of benzo[a]pyrene and six other PAHs that are probably human carcinogens through consumption of these marine species would be associated with 0.27/10(6) increase in the risk of development of cancer over a 70-year life span.     

Sources, vertical fluxes, and equivalent toxicity of aromatic hydrocarbons in coastal sediments of the Río de la Plata Estuary, Argentina

Settling particles and bottom sediments collected at 1, 2.5, and 4 km off the metropolitan Buenos Aires coast in the Río de la Plata were analyzed to evaluate the sources and toxicity of resolved (PAHs) and unresolved (AROUCM) aromatic hydrocarbons. PAHs (0003-2.1 microg g(-1)) and AROUCM (0.01-78 microg g(-1)) presented the highest concentrations nearthe Buenos Aires port and sewer and decreasing values up- and downstream and along on- and offshore gradients. Sediment traps deployed in the Central area revealed large aromatic fluxes (1.3 +/- 1.5 and 31 +/- 47 mg m(-2) day(-1) for PAHs and AROUCM). The composition of sedimentary PAHs was dominated by uniformly distributed high molecular weight pyrogenic PAHs (53 +/- 11% fluoranthene, pyrene, and heavier PAHs), followed by diagenetically derived perylene more abundant in less polluted sites (29 +/- 15%) and lower molecular weight petrogenic PAHs (18 +/- 7.1% phenanthrene, anthracene, and methylated compounds), which covaried inversely with perylene. PAH diagnostic ratios indicated a stronger influence of petrogenic discharges close to the shore and the prevalence of combustion of fossil fuels and vehicle emissions over wood in offshore sediments. Sediment cores showed sustained hydrocarbon levels with decreasing proportion of petrogenic PAHs and relative enrichment of pyrogenic components and perylene down to 20-cm depth. PAH toxicity assessment by sediment quality guidelines (SQG) and dioxin-equivalent factors (PAH TEQ: 0.08-395 pg g(-1) dw) identified 1-2.5 km sediments close to the port and sewer as the most affected area. According to SQG, dibenz[a,h]anthracene and pyrene were the most critical PAHs, followed by benzo[a]pyrene, benz[a]anthracene, and chrysene. In contrast, PAH TEQs were dominated by indeno[1,2,3-cd]pyrene, benzo[k]fluoranthene, benzo[a]pyrene, perylene, and benz[a]anthracene which accounted for an average 86 +/- 5.7% of total TEQs.     

Polycyclic aromatic hydrocarbons in fresh and cold-smoked Atlantic salmon fillets

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in smoked fish as a consequence of cold smoking was studied. Raw fillets of Salmo salar from Norway or the Irish Sea were sampled in a modern smokehouse and examined for PAH content. The same fillets, labeled with an identification number, were sampled immediately after the smoking process and analyzed. Among the investigated compounds, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, and benzo[ghi]perylene were detected in both raw and smoked fillets. No significant difference (P < 0.01) was observed between raw and smoked samples in the concentrations of six PAHs, but significant differences were found for fluorene, anthracene, fluoranthene, benz[a]anthracene, and benzo[ghi]perylene. Results confirm that PAHs concentrations in smoked fish are the product of both sea pollution and the smoking process. A modern smoking plant with an external smoke generator and a mild treatment as described here will not add significantly to the concentration of PAHs, except for some compounds.     

冷冻除脂-气相色谱-串联质谱法检测食用植物油中30 种多环芳烃

建立冷冻除脂--气相色谱-串联质谱检测食用植物油中30?种多环芳烃（polycyclic aromatic hydrocarbons,PAH）的方法。选用6?种氘标记PAH为内标,样品经乙腈--丙酮溶液（4∶1,V/V）于离心管中涡旋提取,10?000?r/min离心5?min,－80?℃对油脂冷冻固化,倾出提取液,再经减压浓缩和氮气吹干,以二氯甲烷复溶,气相色谱--串联质谱多反应监测方式进行检测。结果表明,在相应质量浓度范围内30?种PAH均有良好线性（R2＞0.998）,检出限为0.10～1.83?μg/kg,定量限为0.35～6.11?μg/kg,在5、20?μg/kg和50?μg/kg添加水平下的回收率为67.77%～119.28%,相对标准偏差为1.18%～12.47%。采用本方法对市售11?类38?个食用植物油样品的检测显示,萘、1-甲基萘、2--甲基萘、联苯、2,6--二甲基萘、苊烯、苊、2,3,6--三甲基萘、芴、二苯并噻吩、菲、蒽、1-甲基菲、荧蒽、芘、环戊烯[c,d]芘、苯并[a]蒽、屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[e]芘和苯并[a]芘的检出率均为100%;5--甲基屈、苝、茚并[1,2,3--c,d]芘、二苯并[a,h]蒽、苯并[g,h,i]苝和二苯并[a,l]芘的检出率分别为86.84%、63.16%、81.58%、21.05%、81.58%和26.32%;二苯并[a,e]芘和二苯并[a,h]芘未检出;PAH总量为92.56～905.16?μg/kg,其中苯并[a]芘含量为1.94～7.40?μg/kg,依据食品安全标准限量,PAH处于较安全水平。     

Polycyclic aromatic hydrocarbons in mussels (Mytilus galloprovincialis) from the Ionian Sea, Italy

Concentrations of eight polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[ghi]perylene) were determined in mussels (Mytilus galloprovincialis) collected between June and September 1995 from 10 locations along a sound of sea formed by two inlets (Mar Piccolo) close to the Gulf of Taranto (Ionian Sea, Italy). In mussels the concentrations of total PAHs were between 14.8 and 645.3 microg/kg wet weight. Among the single identified compounds, the predominance of phenanthrene (29.5 microg/kg wet weight) and anthracene (64.7 microg/kg wet weight) was evident. Another relevant pollutant was pyrene (18.4 microg/kg wet weight) followed by fluoranthene (7.2 microg/kg wet weight), whereas the other compounds showed low levels. The mussels that showed the highest total concentrations of PAHs were collected from stations affected by stronger human activities (industrial fallout, urban wastewaters, and contaminants transported via riverine discharge). Our results were similar to those found in areas classified as moderately polluted. This observation suggests the need for an increased effort in controlling sources of pollution in this area recognized as one of the most productive mussel-farming areas in the Italy.     

Polycyclic aromatic hydrocarbon levels and risk assessment for food from service facilities in Korea

ABSTRACT

In this study, levels of benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene (BaP), dibenzo[a,h]anthracene, benzo[g,h,i]perylene and indeno[1,2,3-c,d]pyrene in 412 food items collected from food service facilities in Korea were analysed. The concentrations of the eight polycyclic aromatic hydrocarbons (PAHs) ranged 0.13–0.48 μg/kg. The concentrations of benzo[a]pyrene in all food samples were <1 μg/kg, which is the lowest maximum limit in foods regulated by European Union legislation. PAH contents were employed to conduct exposure and risk assessment. The chronic daily intake of PAHs from 412 food samples was 5.48 × 10^–6-4.70 ×x 10^–4 µg-TEQ_BaP/kg/day with margins of exposure of 1.04 × 10⁹-1.16 × 10¹¹.     

Influence of collagen and natural casings on the polycyclic aromatic hydrocarbons in traditional dry fermented sausage (Petrovská klobása) from Serbia

The aim of this study was to determine the content of polycyclic aromatic hydrocarbons—PAHs (acenaphthylene, anthracene, fluorene, phenanthrene, pyrene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, chrysene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene, and benzo[ghi]perylene)—from Environmental Protection Agency list (United States Environmental Protection Agency) in traditional dry fermented sausage (Petrovská klobása) stuffed in collagen (C) and natural casings (N). Benzo[a]pyrene as well as PAH4 (benz[a]anthracene, benzo[b]fluoranthene, benzo[a]pyrene, and chrysene) were not detected in all examined samples. Results obtained in this study indicated that at the end of drying, as well as at the end of storage period, total content of 13 US-EPA PAH was significantly (P < 0.05) lower in sausages with collagen casing (56.2 and 73.6 μg/kg, respectively) than in sausages with natural casing (137.1 and 206.2 μg/kg, respectively).     

Polycyclic aromatic hydrocarbons in Italian preserved food products in oil

A method based on gas chromatography/ tandem mass spectrometry was used to assess levels of 16 EU priority polycyclic aromatic hydrocarbons (PAHs) in 48 preserved food products in oil including foods such as vegetables in oil, fish in oil and oil-based sauces obtained from the Italian market. The benzo[a]pyrene concentrations ranged from <0.04 to 0.40 µg kg^?1, and 72.9% of the samples showed detectable levels of this compound. The highest contamination level was observed for chrysene with three additional PAHs (benzo[a]anthracene, benzo[b]fluoranthene and benzo[c]fluorene) giving mean values higher than the mean value for benzo[a]pyrene. Chrysene was detected in all the samples at concentrations ranging from 0.07 to 1.80 µg kg^?1 (median 0.31 µg kg^?1). The contamination expressed as PAH4 (sum of benzo(a)pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene), for which the maximum tolerable limit has been set by Commission Regulation (EU) No. 835/2011, varied between 0.10 and 2.94 µg kg^?1.     

三种光敏剂介导的光动力对水体中8种多环芳烃的降解作用

为了探究不同光敏剂(姜黄素、核黄素、金丝桃素)介导的光动力对水体中多环芳烃的降解作用,以含有8种多环芳烃的水体为研究对象,在光敏剂浓度为10μM,光照时间为15 min的条件下,采用光动力方法处理并通过同步荧光法测定水体中的各种多环芳烃。结果表明,姜黄素介导的光动力对多环芳烃的降解效果明显优于核黄素和金丝桃素介导的光动力组。经姜黄素光动力处理后,水体中的8种多环芳烃均发生一定程度的降解,其中,荧蒽和菲的降解率分别为77.07%和78.31%,苯并[k]荧蒽和?的降解率分别为80.10%和85.95%,苯并[a]芘、萘、苯并[a]蒽和蒽的降解率达到95%以上。以上研究表明,与其他两种光敏剂相比,姜黄素介导的光动力对水溶液中的8种多环芳烃均具有显著的降解效果,为该技术在生活用水以及养殖水体污染治理方面的推广应用提供理论依据。     

Benzo[a]pyrene and total polycyclic aromatic hydrocarbons (PAHs) levels in vegetable oils and fats do not reflect the occurrence of the eight genotoxic PAHs

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in 115 samples of olive oil (extra virgin olive oil, virgin olive oil, olive oil, pomace olive oil and blended olive oil), cooking oil (corn oil, sunflower oil, sesame oil, palm olein oil, soya oil, canola oil, mustard oil, peanut oil and mixed vegetable oil) and fat (butter and table margarine) collected from retail stores in Kuwait. Carcinogenic benzo[a]pyrene (BaP) was detected in 43% of the samples analyzed. Benz[a]anthracene and chrysene were detected in 37 and 45% of the samples, respectively, that did not contain BaP. Of the individual non-carcinogenic PAHs, naphthalene showed the highest mean concentration (14 µg kg^?1), while for the carcinogenic PAHs, BaP (0.92 µg kg^?1) and chrysene (0.87 µg kg^?1) showed the highest mean values. Approximately 20% of the samples within the olive oil and cooking oil sub-categories exceeded the EU maximum tolerable limit for BaP, with the highest level of 6.77 and 11.1 µg kg^?1, respectively. For the fat sub-category, 9% of the samples exceeded the tolerance limit, with the highest level of 3.67 µg kg^?1. The Kuwaiti general population's dietary exposure to the genotoxic PAHs (PAH8: benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene and benzo[ghi]perylene) was estimated to be 196 ng day^?1 (3.3 ng kg^?1 bw day^?1, assuming an average adult body weight of 60 kg). Results indicated that PAH8 and BaP_eq (total sum benzo[a]pyrene equivalents) are more reliable measures of the concentrations of other carcinogenic PAHs in oil and fat samples, while BaP and PAHs alone are not good indicators of the occurrence or degree of contamination by carcinogenic PAHs in these food products.     

Assessment of the dietary habits and polycyclic aromatic hydrocarbon exposure in primary school children

Thirty Italian children, 7–9 year aged, living in Naples were investigated on their dietary habits and on polycyclic aromatic hydrocarbon (PAH) exposure by a food diary-questionnaire and one week duplicate diet sample analyses. Daily total food consumption mean value was 632 ± 215 g day^?1, median value 613 g day^?1. The daily energy intake and the diet composition meanly agreed with the official guidelines for the Italian children. Sixteen PAHs were simultaneously detected and, according to the European Food Safety Authority (EFSA) approach, benzo[a]pyrene; benzo[a]pyrene + chrysene (PAH2); PAH2 + benz[a]anthracene + benzo[b]fluoranthene (PAH4); PAH4 + benzo[k]fluoranthene + benzo[ghi]perylene + dibenz[a, h]anthracene + indeno[1,2,3-cd]pyrene (PAH8) were considered in evaluating the children's dietary exposure to PAHs. The benzo[a]pyrene (BaP) median concentrations in foods varied from 0.06 to 0.33 µg kg^?1. Only three samples of cooked foods (one fish and two meat samples) exceeded legal limits fixed by the European Union for BaP. Daily median intakes of benzo[a]pyrene, PAH2, PAH4, and PAH8 were 153; 318; 990; 1776 ng day^?1; their median exposure values were 5; 10; 28; 54 ng kg^?1 bw day^?1. The Margins of Exposure (MOEs) in median consumers agreed with the EFSA safety values except for PAH8.     

Polycyclic aromatic hydrocarbons (PAHs) in yerba mate (Ilex paraguariensis) from the Argentinean market

Polycyclic aromatic hydrocarbons (PAHs) occurrence in 50 samples marketed in the main supermarkets from Argentina was surveyed. A high performance liquid chromatography (HPLC) method was applied with fluorescence detection (FLD) and UV—VIS diodes array detector (DAD) for the analysis of 16 PAHs in “yerba mate” (Ilex paraguariensis), with recoveries higher than 89% and limits of detection and quantification lower than that found by other methodologies in previous studies. Contamination expressed as the sum of 16 analysed PAHs ranged between 224.6 and 4449.5 μg kg^?1 on dry mass. The contamination expressed as PAH4 (sum of benzo(a)pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene) varied between 8.3 and 512.4 μg kg^?1. The correlation coefficient for PAH2 (sum of benzo(a)pyrene and chrysene) and PAH4 groups was 0.99, for PAH2 and PAH8 (sum of benzo(a)pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, dibenzo(a,h)anthracene and indeno(1,2,3cd) pyrene) 0.97 and for PAH4 and PAH8 0.98.     

Polycyclic aromatic hydrocarbons (PAH) in chocolate on the German market

Benzo[a]anthracene (BaA), chrysene (CHR), cyclopenta[c,d]pyrene (CPP), 5-methylchrysene (5MC), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[j]fluGoranthene (BjF), benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DhA), indeno[1,2,3-cd]pyrene (IcP), benzo[g,h,i]perylene (BgP), dibenzo[a,l]pyrene (DlP), dibenzo[a,e]pyrene (DeP), dibenzo[a,i]pyrene (DiP) and dibenzo[a,h]pyrene (DhP), the 15 SCFPAH, assessed to be relevant as well as benzo[c]fluorene (BcL) recommended by the European Food Safety Authority (EFSA), were analysed in different types of chocolate. The sample preparation included accelerated solvent extraction (ASE), size exclusion chromatography (SEC) and solid phase chromatography using small silica gel columns. The individual PAH were separated by gas chromatography using a VF-17ms GC column and detected by high resolution mass spectrometry (HRMS). The investigation of 40 samples of various types of chocolate with different cocoa contents resulted in a median benzo[a]pyrene (BaP) content of 0.22 μg/kg. Furthermore, the results showed a linear correlation between the content of BaP and the sum content of the 16 priority PAH. Therefore, the analysis of BaP as a leading substance seems to be suitable to estimate the PAH contamination in chocolate.     

Factors influencing the national distribution of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in British soils

The polycyclic aromatic hydrocarbons (PAHs) naphthalene, acenaphthylene, acenaphthene, fluorene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, ideno[1,2,3,-cd]-pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene and the polychlorinated biphenyls (PCBs) 8, 18, 28, 29, 31, 52, 77, 101, 105, 114, 118, 123, 126, 128, 138, 141, 149, 153, 156, 157, 163, 169, 170, 171, 180, 183, 187, 189, 194, 199, 201, 206, and 209 were measured in -200 rural soils across Great Britain (GB). Dominance of soil PAH profiles by heavier compounds (4-6 rings) provided initial evidence for the importance of source in governing soil PAH concentrations. No relationship was found between soil organic matter (SOM) and sum concentration of total and "heavy" PAHs, although there was a weak positive relationship with lighter compounds. A spatial statistical technique showed that highest soil PAH concentrations were usually found close to industrial/urban centers where presumably source intensity is highest. PCBs clustered into seven groups, five of which contained a single "dioxin like" PCB, one contained lighter congeners (2-4 chlorines), and one contained heavy congeners (5-10 chlorines). Linear regressions with SOM explained up to 24.3% of variation for the sum concentration of penta- to deca- congeners, but <1% for the lighter congener groups. No significant relationships were found with latitude. Spatial statistical techniques showed clusters of high soil PCB concentrations predominantly in west and south east GB, either associated with urbanized areas or on the West coast.