Risk assessment for human consumption of perfluorinated compound-contaminated freshwater and marine fish from Hong Kong and Xiamen

Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g⁻¹ to 0.37-8.7 ng g⁻¹ respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern.     

Simultaneous determination of organochlorine pesticides and bisphenol A in edible marine biota by GC-MS

A study to assess the level of organochlorine pesticides (OCPs) and bisphenol A (BPA) in edible marine biota collected from coastal waters of Malaysia was conducted using GC-MS and SPE extraction. An analytical method was developed and validated to measure the level of 15 OCPs and BPA simultaneously from five selected marine species. It was observed that some samples had low levels of p,p′-DDE, p,p′-DDT and p,p′- DDD ranging from 0.50 ng g⁻¹ to 22.49 ng g⁻¹ dry weight (d.w) but significantly elevated level of endosulfan I was detected in a stingray sample at 2880 ng g⁻¹ d.w. BPA was detected in 31 out of 57 samples with concentration ranging from below quantification level (LOQ: 3 ng g⁻¹) to 729 ng g⁻¹ d.w. The presence of OCPs is most likely from past use although there is also indication of illegal use in recent times. The study also reveals that BPA is more widely distributed in coastal species caught off the coast of the most developed state. The potential health risk from dietary intakes of OCPs and BPA from the analysed fish species was negligible.     

Diastereoisomer- and enantiomer-specific determination of hexabromocyclododecane in fish oil for food and feed

Fish oils are one of the main sources of ω-3 fatty acids. However, they can present elevated levels of some lipophilic pollutants, such as hexabromocyclododecanes (HBCDs). Since data about HBCDs in fish oil samples are very limited, in this study, 25 samples of fish oil for feed and food have been analyzed. Total HBCDs, as well as, α-, β- and γ-diastereoisomers have been determined. Total HBCDs ranged from 0.09 to 26.8 ng g⁻¹, with higher concentrations in fish oil for feed (average value of 9.69 ng g⁻¹) than those for food (1.14 ng g⁻¹). Concentrations of α-HBCD (average value of 4.12 ng g⁻¹ in feed samples and 0.48 ng g⁻¹ in food samples) and γ-HBCD (5.05 and 0.43 ng g⁻¹ respectively) were higher than that of β-HBCD (0.52 and 0.19 ng g⁻¹ respectively) in most of the samples. However, none of them was predominant in the samples. Concentrations of HBCDs were compared to concentrations of other pollutants and correlation between dioxin and dioxin-like PCBs levels and HBCDs levels were observed. Intake of HBCDs was calculated for fish oil with human consumption purposes and it ranged from 0.08 to 5.38 ng HBCDs d⁻¹, which could contribute significantly to HBCDs total intake. Enantiomeric fractions were also determined. No clear enrichment was observed for γ-HBCD, while (−)-α-HBCD enrichment was detected in some samples.     

Bisphenol A in human placental and fetal liver tissues collected from Greater Montreal area (Quebec) during 1998-2008

In this study, the presence of bisphenol A (BPA) in human placental and fetal liver samples collected from 1998 to 2008 was investigated to provide a more detailed analysis of the transfer of BPA across the placenta and fetal exposure to BPA. The average concentrations in placental samples were 12.6 ng g⁻¹ for free BPA, 17.2 ng g⁻¹ for BPA-glu, and 30.2 ng g⁻¹ for total BPA. The highest concentrations in placental samples were 165 ng g⁻¹ for free BPA, 178 ng g⁻¹ for BPA-glu, and 280 ng g⁻¹ for total BPA. Samples with higher levels of BPA-glu had higher levels of free BPA in general. Fetal age was observed to have a significant effect on BPA-glu levels in placental samples, but not on free or total BPA. The percentages of free BPA relative to total BPA for the placental samples varied considerably from 4.2% to 100%, suggesting that the ability of maternal liver and/or the placenta to conjugate BPA is highly variable during early to mid-gestation. The average concentrations in fetal liver samples were 9.02 ng g⁻¹ for free BPA, 19.1 ng g⁻¹ for BPA-glu, and 25.8 ng g⁻¹ for total BPA. The highest concentrations in fetal liver samples were 37.7 ng g⁻¹ for free BPA, 93.9 ng g⁻¹ for BPA-glu, and 123 ng g⁻¹ for total BPA. The percentages of free BPA level relative to total BPA for all fetal liver samples varied from 12.4% to 99.1%, indicating extensive variability in the ability of the human feto-placental unit to glucuronidate BPA.     

Distribution of bisphenol-A, triclosan and n-nonylphenol in human adipose tissue, liver and brain

In this study, an analytical method was optimized for the determination of bisphenol-A (BPA), triclosan (TCS) and 4-n-nonylphenol (4n-NP), environmental contaminants with potential endocrine disruptive activities, in human tissues. The method consisted of a liquid extraction step, derivatization with pentafluorobenzoylchloride followed by a clean-up on acidified silica and detection with gas chromatography coupled with mass spectrometry (GC-ECNI/MS). Recoveries ranged between 92% and 102% with a precision below 5%. Limits of quantification ranged between 0.3-0.4 ng g⁻¹, 0.045-0.06 ng g⁻¹ and 0.003-0.004 ng g⁻¹ for BPA, TCS and 4n-NP in different tissues, respectively. The method was applied for the determination of BPA, TCS and 4n-NP in paired adipose tissue, liver and brain samples from 11 individuals. BPA could be detected in almost all tissues, with the highest concentrations found in adipose tissue (mean 3.78 ng g⁻¹), followed by liver (1.48 ng g⁻¹) and brain (0.91 ng g⁻¹). TCS showed the highest concentrations in liver (3.14 ng g⁻¹), followed by adipose tissue (0.61 ng g⁻¹), while it could be detected in only one brain sample. Levels of 4n-NP were much lower, mostly undetected, and therefore 4n-NP is considered of minor importance for human exposure. Despite the measurable concentrations in adipose tissue, these compounds seem to have a low bioaccumulation potential. The reported concentrations of free BPA in the various tissues are slight disagreement with pharmacokinetic models in humans and rats and therefore the possibility of external contamination with BPA during sample collection/storage cannot be ruled out.     

Analysis of mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDD/PXDFs) in soil by gas chromatography tandem mass spectrometry (GC-MS/MS)

Mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDD/PXDFs, X = Br, Cl) are formed through combustion processes, and may be more toxic than their corresponding chlorinated and brominated analogues. With 4600 potential congeners, limited analytical standards, and complex environmental matrices, PXDD/PXDFs present a significant analytical challenge. Gas chromatography tandem mass spectrometry (GC-MS/MS) offers both selectivity and sensitivity through multiple reaction monitoring of unique transitions in a novel approach to PXDD/PXDF congener identification. Method validation was performed through analysis of soil samples obtained from a recycling plant fire. Of the PXDD/PXDFs examined, monobromo-dichlorodibenzofuran was the most prevalent, ranging in concentration from 8.6 ng g⁻¹ to 180 ng g⁻¹. Dibromo-dichlorodibenzo-p-dioxin, a compound of toxicological concern, ranged from 0.41 ng g⁻¹ to 10 ng g⁻¹. Concentrations of PXDD/PXDFs were between 6% and 10% that of the corresponding polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs), with the exception of dibromo-dichlorodibenzo-p-dioxin concentrations, which were 36% that of tetrachlorodibenzo-p-dioxins. Higher levels of polybrominated PXDD/PXDFs may indicate a significant bromine source was present during combustion.     

Polybrominated diphenyl ethers (PBDEs) and mercury in fish from lakes of the Tibetan Plateau

High mountains may act as cold traps for globally transported persistent organic pollutants (POPs) and mercury (Hg). In the present study, 60 fish samples were collected from eight alpine lakes across the Tibetan Plateau. Concentrations of polybrominated diphenyl ethers (PBDEs), total mercury (HgT) and methyl mercury (MeHg) were quantified in the fish muscle tissues to improve the understanding of pollution status and factors regulating the transport and fate of these contaminants on the Plateau. The results showed that lake-averaged ∑₁₄PBDEs concentration was between 0.09 ng g⁻¹ dw and 4.32 ng g⁻¹ dw, which was lower than those reported for European mountains. The total mercury concentration in individual fish ranged from 243 to 2384 ng g⁻¹ dw, and that of MeHg from 131 to 1610 ng g⁻¹ dw, which is much higher than those reported in other mountain fish. The spatial variation of PBDEs and mercury in the Plateau is largely controlled by the specific meteorological patterns.     

Polychlorinated biphenyls and organochlorine pesticides in local waterbird eggs from Hong Kong: risk assessment to local waterbirds

The contamination status of the marine environment in Hong Kong was studied by measuring concentrations of organochlorine (OC) pollutants (i.e., hexachlorobenzene, aldrin, dieldrin, endrin, mirex, total heptachlor, total chlordane, total DDTs, total PCBs, and total toxaphenes) in the eggs of selected waterbird species from different locations around the city: Little Egret (Egretta garzetta) and Chinese Pond Heron (Ardeola bacchus) from Mai Po Village, Great Egret (Ardea alba) and Black-crowned Night Heron (Nycticorax nycticorax) from A Chau, and Chinese Pond Heron (A. bacchus) from Ho Sheung Heung. The mean concentrations of total PCBs and total DDTs ranged from 191-11 100 ng g⁻¹ lipid and 453-49 000 ng g⁻¹ lipid, respectively. Recent exposure of waterbirds to technical chlordane was found in Hong Kong. The risk characterization demonstrated potential risks to birds associated with exposure to DDE, which was found to cause a reduction in survival of young in Hong Kong Ardeids based on the endpoint in the risk assessment.     

Determinations of hexabromocyclododecane (HBCD) isomers in channel catfish, crayfish, hen eggs and fish feeds from China by isotopic dilution LC-MS/MS

HBCD is widely used brominated flame retardant, which is increasingly reported in the environment. A new isotopic dilution LC-MS/MS method was developed to determine three HBCD isomers, α-, β- and γ-HBCD in channel catfish, crayfish, hen eggs and fish feeds in this study, and especially for the first time HBCD isomers composition in crayfish, hen eggs and fish feeds. Soxhlet extractor and GPC cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and LC and MS/MS conditions were optimized. The limits of quantitation values of 0.01, 0.005 and 0.005 ng g⁻¹ wet weight in channel catfish and crayfish were calculated for three HBCD isomers, respectively; so did 0.1, 0.05 and 0.05 ng g⁻¹ wet weight in eggs and 0.2, 0.1, 0.1 ng g⁻¹ wet weight in fish feeds. Recoveries of α-HBCD, β-HBCD and γ-HBCD were ranged between 75% and 105% for these productions at medium and high-level spiked samples, and between 60% and 85% at low-level spiked samples. The established methods were therefore suitable for the determinations of three HBCD isomers in these productions at trace contamination levels. Moreover, thirty commercial channel catfish, crayfish, hen eggs and fish feeds samples collected from local markets, and thirty home-produced hen eggs from private owners in Hubei province of China, were analyzed to determine whether these productions were contaminated by HBCD. Using the established methods, HBCD emerged in 4 of 30 fish feeds and 3 of 30 home-produced eggs, and in low-ng g⁻¹ wet weight.     

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) in seven different marine bird species from Iceland

Data on distribution, concentration and trends of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) is scarce in biota from the sub-Arctic region of the Atlantic. The present study is an investigation on PBDE and HBCD concentrations in eggs from seven marine bird species from Iceland, i.e. common eider (Somateria mollissima), arctic tern (Sterna paradisaea), guillemot (Uria aalge), fulmar (Fulmarus glacialis), lesser black-backed gull (Larus fuscus), great black-backed gull (Larus marinus) and great skua (Stercorarius skua). Concentrations of sum PBDEs ranged from 44 ng g⁻¹ fat in eider eggs to 2400 ng g⁻¹ fat in great skua eggs. The contribution of different PBDE congeners to the sum concentration differed between species. Concentration of HBCDs (sum of α−,β⁻ and γ−HBCD) ranged from 1.3 ng g⁻¹ fat in arctic tern eggs to 41 ng g⁻¹ fat in great black-backed gull. PCA on PBDE and HBCD shows different trends between the two BFR groups, further indicating different sources/usage. Investigations on any potential health or population effects of environmental pollutants on the great skua are advised since both the PBDE and HBCD concentrations are high.     

Bioaccessibility of polychlorinated biphenyls in workplace dust and its implication for risk assessment

Human exposure to bioaccessible PCBs via indoor dust is limited around the world. In the present study, the workplace dust sample from commercial office, hospital, secondary school, shopping mall, electronic factory and manufacturing plant were collected from Hong Kong for PCBs analyses. Total PCBs concentrations ranged from 46.8 to 249 ng g⁻¹, with a median of 107 ng g⁻¹. Manufacturing plant showed the highest concentration among all of sampling sites. PCB 77 was found as the dominant congeners. The bioaccessibility of PCBs in small intestinal juice ranging from 8.3% to 26.0% was significantly higher than that in gastric condition, ranging from 4.8% to 12.4%. In addition, significant negative correlations (p < 0.05) were observed between K_OW and bioaccessibility for all workplace dust samples. Risk assessment indicated that the averaged daily dose of dioxin-like PCBs via non-dietary intake of workplace dust, considering the bioaccessibility of PCBs, were much lower than the TDI of dioxins (2.3 pg WHO-TEQ kg bw⁻¹ d⁻¹) established by Joint FAO/WHO Expert Committee on Food Additives.     

The impact of production type and region on polychlorinated biphenyl (PCB), polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations in Canadian chicken egg yolks

Chicken eggs from five different production types (conventional, omega-3 enriched, free range, organic and free run) were collected, when available, from three regions (west, central and east) of Canada to determine persistent organic pollutant (POP) concentrations. Total polychlorinated biphenyl (PCB) concentrations (∑37 congeners) in yolks from the eggs ranged from 0.162 ng g⁻¹ lipid to 24.8 ng g⁻¹ lipid (median 1.25 ng g⁻¹ lipid) while the concentration of the sum of the 6 indicator PCBs ranged from 0.100 ng g⁻¹ lipid to 9.33 ng g⁻¹ lipid (median 0.495 ng g⁻¹ lipid). Total polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations ranged from 2.37 pg g⁻¹ lipid to 382 pg g⁻¹ lipid (median 9.53 pg g⁻¹ lipid). The 2005 WHO toxic equivalency (TEQ) ranged from 0.089 pg TEQ_{PCDD/F+dioxin-like[DL]-PCB} g⁻¹ lipid to 12.8 pg TEQ_{PCDD/F+DL-PCB} g⁻¹ lipid (median 0.342 pg TEQ_{PCDD/F+DL-PCB} g⁻¹ lipid). PCB and PCDD/F concentrations were significantly different (p < 0.001) in egg yolks from different regions of collection. In contrast to observations in Europe, PCB and PCDD/F concentrations in Canadian egg yolks were not impacted solely by the production type (e.g., conventional, free range, organic, etc.) used to maintain the laying chickens. Additionally, only one Canadian free range yolk from western Canada (12.8 pg TEQ_{PCDD/F+DL-PCB} g⁻¹ lipid) exceeded the European toxic equivalent concentration limits for eggs (5 pg TEQ_{PCDD/F+DL-PCB} g⁻¹ lipid). This differs from observations in Europe where free range/home produced eggs frequently have higher POP concentrations than eggs from other production types. Median PCB dietary intake estimates based on consumption of eggs were less than 10 ng d⁻¹ while median PCDD/F intakes were less than 45 pg d⁻¹.     

Polychlorinated biphenyls in freshwater salmonids from the Kerguelen Islands in the Southern Ocean

The Subantarctic Kerguelen Islands (49°S, 70°E) contain freshwater ecosystems among the most isolated in the world. Concentrations of polychlorinated biphenyls (PCBs) were assessed in the muscle of 48 brook trout and 38 brown trout caught during summer and spring 2006 in the rivers, lakes and ponds of Kerguelen. The sum of 29 PCBs averaged 404 and 358 ng g⁻¹ lipid, and dioxin-like PCB was 19 and 69 ng g⁻¹ lipid, in brook and brown trout, respectively. The values showed a high variability and some fish accumulated PCBs at levels similar to those of fish from impacted areas. While inter-sex differences were limited, the season and the morphotype appeared to have the most influence. Fish captured in summer had muscle PCB concentrations about three times higher than those caught in spring and the ‘river’ morphotype of brook trout showed the highest PCB levels.     

Detection of Dechlorane Plus and brominated flame retardants in marketed fish in Japan

Fish samples purchased from Japanese markets were analyzed for Dechlorane Plus (DP)(syn-, anti-), polybrominated diphenyl ether (PBDE), and hexabromocyclododecane (HBCD)(α, γ). Twenty fish were analyzed using gas chromatography-mass spectrometry for DP and PBDE, and using liquid chromatography-tandem mass spectrometry for HBCD. DP was detected in 18 samples and ∑DP concentrations were <0.2-14.2 pg g⁻¹ wet wt. Among the DP isomers, anti-DP was the dominant residue observed in this study. PBDE was detected in all samples. Concentrations of ∑PBDE ranged from 2.2 to 878 pg g⁻¹ wet wt. HBCD was detected in 18 samples, and ∑HBCD concentrations were <0.02-21.9 ng g⁻¹ wet wt. In fish landed near the East China Sea and the Sea of Japan, we detected relatively high concentrations of DP, PBDE, and HBCD. These results indicate that the seawaters around East Asia are contaminated with flame retardants. This study demonstrates the presence of DP in fish marketed in Japan for the first time.     

Enrichment of polycyclic aromatic hydrocarbons (PAHs) in mariculture sediments of Hong Kong

Surface and core sediments collected from six fish farms in Hong Kong and from reference sites were investigated for the enrichment and sources of polycyclic aromatic hydrocarbons (PAHs). Moderately high ∑PAH₁₆ levels (123-947 ng g⁻¹, mean: 450 ng g⁻¹) were found in the surface aquaculture sediments. In comparison with the sediments from the reference sites, the average enrichment percentage of total organic carbon (TOC) and PAHs in surface sediments were 21.4 and 43.8%, respectively, and in the core sediments, 24.6 and 73.7%, respectively. Mathematical source apportionment analyses (i.e. isomer ratios, hierarchical cluster analysis, principal components analysis with multiple linear regression analysis) suggested a higher percentage of petrogenic sources in aquaculture sediments. The fish feeds might be the main source of the enriched PAHs in the aquaculture sediments. To our knowledge, this is the first study showing that PAHs in aquaculture sediments could be attributed to human aquaculture activities.     

Polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in marine fish from four areas of China

The levels of polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) were determined in marine fish from four areas of China (South China Sea, Bohai Sea, East China Sea, and Yellow Sea) using GC/NCI-MS and GC/ITMS, respectively. Total concentrations of eight PBDEs (BDE-28, 47, 99, 100, 153, 154, 183 and 209) in all samples ranged from 0.3 ng g⁻¹ ww (wet weight) to 700 ng g⁻¹ ww, with median and mean values of 85 ng g⁻¹ ww and 200 ng g⁻¹ ww, respectively. BDE-209 and BDE-47 were the major congeners in all samples, contributing 54% and 19% to the total concentration, respectively. The sum of seven indicator PCB levels (CB-28, 52, 101, 118, 138, 153, and 180) ranged from 0.3 ng g⁻¹ ww to 3.1 μg g⁻¹ ww, with median and mean values of 6.4 ng g⁻¹ ww and 398 ng g⁻¹ ww, respectively. High contributions of CB-138 (32%) and CB-153 (25%) were found in all samples. In general, pollutants measured in this study were at high levels when compared with previous studies from other regions in the world. The relative abundance of BDE-209 may suggest that deca-BDE sources existed in studied area. And principal component analysis (PCA) showed that there were other PBDE sources in Yellow Sea. The pattern and PCA showed that PCB pollutions came from similar sources in the studied areas. In addition, concentrations of ∑₇PBDEs (u/209) were strongly correlated with those of ∑₇PCBs in all fish (r = 0.907, n = 44).     

Risk assessment of xenoestrogens in a typical domestic sewage-holding lake in China

Release of domestic sewage leads to accumulation of xenoestrogens in holding waters, especially in closed or semi-enclosed waters such as lakes. In the study, the occurrence, distribution, estrogenic activity and risk of eight xenoestreogens were evaluated in Lake Donghu, China. Nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) were identified as the main xenoestrogens ranging from tens of ng L⁻¹ (in the surface water) or ng g⁻¹ dw (in the suspended particles and sediment) to tens of μg L⁻¹ or μg g⁻¹ dw. The sum of 17β-estradiol equivalents (∑EEQs) ranged from 0.32 to 45.02 ng L⁻¹ in the surface water, 0.53 to 71.86 ng g⁻¹ dw in the suspended particles, and 0.09 to 24.73 ng g⁻¹ dw in the sediment. Diethylstilbestrol (DES) was determined as the main contributor to ∑EEQs followed by NP. The risk assessment showed a higher risk in the surface water than in the suspended particles and sediment in such domestic sewage-holding lake.     

Monitoring of environmental contaminants in raw bovine milk and estimates of dietary intakes of children in South Korea

Persistent organic pollutants (POPs) are ubiquitous residual contaminants in the environment and in the food chain. Milk is an important matrix for monitoring POP contamination. This study determined the concentrations of POPs including polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in raw bovine milk, and the data was used to estimate dietary intakes in South Korea. The average concentrations of PBDEs, HCB, PCDD/Fs, and DL-PCBs in raw milk were 0.29 ng g⁻¹ fat, 0.50 ng g⁻¹ fat, 0.27 pg TEQ g⁻¹ fat, and 0.33 pg TEQ g⁻¹ fat, respectively. No significant relationship was found between the concentrations of analytes and the regions sampled. The dietary intakes of PBDEs from the consumption of milk was calculated to be 0.26, 0.10, and 0.05 ng kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. The dietary intakes of HCB was calculated to be 0.44, 0.16, and 0.09 ng kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. The dietary intakes of PCDD/Fs and DL-PCBs was calculated to be 0.78, 0.29, and 0.16 pg TEQ kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. These results indicated that the residual levels of PBDEs, HCB, PCDD/Fs, and DL-PCBs in raw bovine milk were within safe levels.     

Air quality assessment by tree bark biomonitoring in urban, industrial and rural environments of the Rhine Valley: PCDD/Fs, PCBs and trace metal evidence

Tree barks were used as biomonitors to evaluate past atmospheric pollution within and around the industrial zones of Strasbourg (France) and Kehl (Germany) in the Rhine Valley. The here estimated residence time for trace metals, PCBs and PCDD/Fs in tree bark is >10 years. Thus, all pollution observed by tree bark biomonitoring can be older than 10 years. The PCB baseline concentration (sum of seven PCB indicators (Σ₇PCB_ind)) determined on tree barks from a remote area in the Vosges mountains is 4 ng g⁻¹ and corresponds to 0.36 × 10⁻³ ng toxic equivalent (TEQ) g⁻¹ for the dioxin-like PCBs (DL-PCBs). The northern Rhine harbor suffered especially from steel plant, waste incinerator and thermal power plant emissions. The polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) concentrations analyzed in tree barks from this industrial area range between 392 and 1420 ng kg⁻¹ dry-weight (dw) corresponding to 3.9 ng TEQ_PCDD/Fs kg⁻¹ to 17.8 ng TEQ_PCDD/Fs kg⁻¹, respectively. Highest PCDD/F values of 7.2 ng TEQ kg⁻¹ to 17.8 ng TEQ kg⁻¹ have been observed close to and at a distance of <2 km southwest of the chemical waste incinerator. However, very close to this incinerator lowest TEQ dioxin-like PCB (TEQ_DL-PCB) values of 0.006 ng TEQ g⁻¹ have been found. On the other hand close to and southwest and northeast of the steel plant the values are comparatively higher and range between 0.011 ng TEQ g⁻¹ and 0.026 ng TEQ g⁻¹. However, even stronger Σ₇PCB_ind enrichments have been observed at a few places in the city center of Kehl, where ΣDL-PCB values of up to 0.11 ng TEQ g⁻¹ have been detected. These enrichments, however, are the result of ancient pollutions since recent long-term measurements at the same sites indicate that the atmospheric PCB concentrations are close to baseline. Emissions from an old landfill of waste and/or great fires might have been the reasons of these PCB enrichments. Other urban environments of the cities of Kehl and Strasbourg show significantly lower Σ₇PCB_ind concentrations. They suffer especially from road and river traffic and have typically Σ₇PCB_ind concentrations ranging from 11 ng g⁻¹ to 29 ng g⁻¹. The PCB concentration of 29 ng g⁻¹ has been found in tree bark close to the railway station of Strasbourg. Nevertheless, the corresponding TEQ_DL-PCB are low and range between 0.2 × 10⁻³ ng TEQ g⁻¹ and 7 × 10⁻³ ng TEQ g⁻¹. Samples collected near road traffic are enriched in Fe, Sb, Sn and Pb. Cd enrichments were found close to almost all types of industries. Rural environments not far from industrial sites suffered from organic and inorganic pollution. In this case, TEQ_DL-PCB values may reach up to 58 × 10⁻³ ng TEQ g⁻¹ and the corresponding V, Cr, Co, Ni, and Cd concentrations are comparatively high.     

PCDD/F, PCB, PBDE, HBCD and chlorinated pesticides in a Swedish market basket from 2005--levels and dietary intake estimations

Based on consumption data statistics, food items from four regions in Sweden were sampled in a so-called market basket study. Food items from five food groups, i.e. fish, meat, dairy products, eggs and fat/oils, were analyzed for persistent organic pollutants (POPs) followed by per capita intake calculations. The highest levels of PCDD/F, PCB, PBDE, HBCD and chlorinated pesticides were found in the fish/fish products. The estimated market basket per capita intake of PCDD/F and dl-PCB was 0.7 pg WHO-TEQ kg bw⁻¹ d⁻¹ (TEFs from 1998). The intake of ∑PCB was estimated to 4.9 ng kg bw⁻¹ d⁻¹ and fish was found to be the major contributor with 64%. The intake of ∑PBDE was found to be 0.7 ng kg bw⁻¹ d⁻¹. Fish (38%) and dairy products (31%) were the largest contributors to the total PBDE intake. The intake of HBCD was estimated to 0.14 ng kg bw⁻¹ d⁻¹. HBCD mainly came from fish (65%), but also dairy products (24%) and meat (10%) contributed. Also regarding the chlorinated pesticides, fish was found to be the major contributor, with 51% of the ∑DDT coming from fish. The intake of ∑DDT, ∑HCH and HCB was 4.0, 1.0 and 1.1 ng kg bw⁻¹ d⁻¹, respectively. Most of the ∑HCH and HCB originate from dairy products (43% and 55%, respectively). This study shows that the levels, and intake, of different POPs from food of animal origin in the market basket of 2005 seem to have decreased since the market basket study in 1999.