Probabilistic intake assessment of polybrominated diphenyl ethers and omega-3 fatty acids through fish consumption

Food intake is one of the principal exposure routes of polybrominated diphenyl ethers (PBDEs) in humans. This study focuses on fish consumption as a PBDE exposure route. A probabilistic intake assessment of PBDEs and healthy long chain omega-3 PUFAs (LC n-3 PUFAs) was conducted for Belgian fish consumers in order to study the balance of the intake of LC n-3 PUFAs and PBDEs. Based on the observed fish consumption level in the sample, the mean intake of brominated diphenyl ether (BDE)-28, 47, 99, 100, 153, and 154 via fish was 0.85 ng/kg body weight (bw)/day and the intake of LC n-3 PUFAs was 3.45 mg/kg bw/day, being low compared to the recommendations. Scenario analyses showed that consuming 150 g salmon twice a week is advisable to achieve the recommended LC n-3 PUFA intake with a rather low PBDE intake. When replacing 150 g salmon by herring, the PBDE intake is higher without an increase in LC n-3 PUFAs. In contrast, the combination of cod and salmon leads to a similar PBDE intake compared to twice a week salmon, but to a lower LC n-3 PUFA intake. In conclusion, the methodology presented in the paper allows balancing benefits and risks related to fish consumption.     

Long-term daily intake estimates of polychlorinated dibenzo-p-dioxins and furans,polychlorinated biphenyls and polybrominated diphenylethers from food in Finnish children: risk assessment implications

Food is contaminated by polychlorinated dibenzo-p-dioxins and furans (PCDD/F), polychlorinated biphenyls (PCB) and polybrominated diphenylethers (PBDE) worldwide. Previous data show elevated intakes in children. We determined intakes of POPs in Finnish children. Because no children-specific safe limit values exist, we used tolerable daily intakes (TDIs) set for adults by international expert bodies to examine the proportion of the study population that exceed those limits. We utilised dietary monitoring data with food consumption of Finnish boys and girls aged 1–6 years, measured the contaminant concentrations in all the main food items and calculated age-specific contaminant sum and congener-specific long-term daily intake levels. Our food intake and contaminant data correspond to years 2002–2005. The long-term upper-bound dioxin intakes ranged between 0.1 and 12.8?pg WHO_PCDD/F-PCB-TEQ/kg bw/d (min and max). An immediate TDI for WHO_PCDD/F-PCB-TEQs of 4.0?pg/kg?bw/d were exceeded by 2.5%–7.5% of the children. PBDE long-term upper-bound intake was between 0.1 and 5.8?ng/kg bw/d (min and max). Congener-specific analyses indicated a typical Finnish adult exposure pattern of the children to PCDD/Fs, PCBs and PBDEs. The highest POP intakes were observed in children aged 3 years. Long-term daily PCDD/F, PCB and PBDE intakes among Finnish children varied greatly between individuals and ages. In each age group of the study population, there was a proportion of children with their WHO_PCDD/F-PCB-TEQ intake exceeding considered safe limits set for adults. Based on the exposure profile reported herein, children should be clearly considered as a specific sub-population in food-mediated contaminant risk assessment.     

Long-term daily intake estimates of polychlorinated dibenzo-p-dioxins and furans, polychlorinated biphenyls and polybrominated diphenylethers from food in Finnish children: risk assessment implications

Food is contaminated by polychlorinated dibenzo-p-dioxins and furans (PCDD/F), polychlorinated biphenyls (PCB) and polybrominated diphenylethers (PBDE) worldwide. Previous data show elevated intakes in children. We determined intakes of POPs in Finnish children. Because no children-specific safe limit values exist, we used tolerable daily intakes (TDIs) set for adults by international expert bodies to examine the proportion of the study population that exceed those limits. We utilised dietary monitoring data with food consumption of Finnish boys and girls aged 1-6 years, measured the contaminant concentrations in all the main food items and calculated age-specific contaminant sum and congener-specific long-term daily intake levels. Our food intake and contaminant data correspond to years 2002-2005. The long-term upper-bound dioxin intakes ranged between 0.1 and 12.8?pg WHO(PCDD/F-PCB)-TEQ/kg bw/d (min and max). An immediate TDI for WHO(PCDD/F-PCB)-TEQs of 4.0?pg/kg?bw/d were exceeded by 2.5%-7.5% of the children. PBDE long-term upper-bound intake was between 0.1 and 5.8?ng/kg bw/d (min and max). Congener-specific analyses indicated a typical Finnish adult exposure pattern of the children to PCDD/Fs, PCBs and PBDEs. The highest POP intakes were observed in children aged 3 years. Long-term daily PCDD/F, PCB and PBDE intakes among Finnish children varied greatly between individuals and ages. In each age group of the study population, there was a proportion of children with their WHO(PCDD/F-PCB)-TEQ intake exceeding considered safe limits set for adults. Based on the exposure profile reported herein, children should be clearly considered as a specific sub-population in food-mediated contaminant risk assessment.     

Polybrominated diphenyl ethers contamination of United States food

Elevated levels of polybrominated diphenyl ethers (PBDEs), a type of brominated flame retardant, were recently detected in U.S. nursing mothers' milk. These halogenated compounds chemically and toxicologically resemble others such as polychlorinated biphenyls (PCBs), whose route of intake is almost exclusively through food of animal origin. This study is the first to report the levels of PBDEs in U.S. foods in a market basket survey of 30 food types (total of 32 food samples) from three major supermarket chains in Dallas, TX. Food samples were almost exclusively foods of animal origin: meat, fish, and dairy products. Thirteen PBDE congeners were measured for each sample. Levels were then compared to existing PBDE food studies from other countries where available. In this study, levels of PBDEs are highest in fish, then meat, and lowest in dairy products; median levels were 1725 (range 8.5-3078), 283 (range 0.9-679), and 31.5 (0.2-1373), parts per trillion (ppt), or pg/g, wet weight, respectively. Nonfat milk did not have any detectable PBDE levels. In fish, PBDE congener 47 (2,2',4,4'-tetraBDE) contributes up to 70% of the total PBDEs, followed by congeners 100 (2,2',4,4',6) and 99 (2,2',4,4',5). In meat congener 99 predominates, followed by 47. In dairy, BDE 47 predominates followed by 99. U.S. food PBDE levels measured in this study are higher than reported in two other published market based studies from Spain and Japan. Although these findings are preliminary and will be updated with analyses of new samples, they suggest that food is a major route of intake for PBDEs.     

Elevated PBDE levels in pet cats: sentinels for humans?

Co-incident with the introduction of polybrominated diphenyl ethers (PBDEs) into household materials nearly 30 years ago, feline hyperthyroidism (FH) has increased dramatically. Risk of developing FH is associated with indoor living and consumption of canned catfood. We hypothesized that increases in FH were, in part, related to increased PBDE exposure, with key routes of exposure being diet and ingestion of house dust. This study was designed to determine whether body burdens of PBDEs in hyperthyroid (HT) cats were greater than that of young or sick non-HT cats. Serum samples and clinical information were collected from 23 cats. Serum and dry and canned cat food were analyzed for PBDEs. A spectrum of BDE congeners was detected in all cats, with BDE-47, 99, 207, and 209 predominating. Mean +/- standard error (and median) cumulative sigma PBDE serum concentrations of young, old non-HT, and HT cats were 4.3 +/- 1.5 (3.5), 10.5 +/- 3.5 (5.9), and 12.7 +/- 3.9 (6.2) ng/mL, respectively. Due to high variability within each group, no association was detected between HT cats and sigma PBDE levels. Indicative of age- or disease-dependent changes in PBDE metabolism, BDE-47/99 ratios were inversely correlated with age, and 47/99 and 100/ 99 ratios in HT cats were significantly lower than those in the other cats. Overall, sigma PBDE levels in cats were 20- to 100-fold greater than median levels in U.S. adults. Our results support the hypothesis that cats are highly exposed to PBDEs; hence, pet cats may serve as sentinels to better assess human exposure and adverse health outcomes related to low-level but chronic PBDE exposure.     

Measurement of polybrominated diphenyl ethers on hand wipes: estimating exposure from hand-to-mouth contact

Estimates of exposure to the flame-retardant polybrominated diphenyl ethers (PBDEs) in dust are very poor due to limited knowledge about dust ingestion. This study was undertaken to determine if PBDEs could be measured on hand wipes, and if so, to determine the distribution of levels present on the skin surface area to provide preliminary exposure estimates from hand-to-mouth contact. Hand wipes were collected from 33 individuals residing in the United States using sterile gauze pads soaked in isopropyl alcohol. The total PBDE residue collected on the wipes ranged from 2.60 to 1982 ng, with a median value of 130 ng, or normalized to hand surface area, a concentration of 135 pg/cm2. The fully brominated congener, BDE 209, was also detected and ranged from < DL to 270 ng with a median value of 26 ng. Congener patterns observed on the wipes were similar to patterns observed in house dust samples, consisting of congeners associated with the PentaBDE and DecaBDE mixtures, suggesting that the source of PBDEs to the hands may be dust particles. However, PBDE hand residues may also be a result of direct contact with PBDE-laden products, leading to adsorption to the skin surface oils. Repeated wipe sampling from three individuals suggests that sigmaPBDE levels on the hand may be relatively consistent for some individuals but not for others. Furthermore, levels of sigmaPBDEs were greater on the bottom of the hands relative to the top of the hands. Using these values we have calculated potential human exposure from hand-to-mouth contact. The median exposure estimates for children and adults are 1380 and 154 ng/day, respectively, whereas the 95th percentile exposure estimates were 6090 and 677 ng/day, respectively. These estimates are greater than dietary intake rates and suggest hand-to-mouth contact may be a key exposure route for PBDEs.     

Effects of river flooding on polybrominated diphenyl ether (PBDE) levels in cows' milk, soil, and grass

The first investigation into PBDE levels in food produced from flood-prone land on industrial river catchments was conducted. In August 2008 samples of cows' milk, along with grass and soil were taken from 5 pairs of flood-prone and control farms on the River Trent (Central UK). The sum of 7 BDE congeners (28, 47, 99, 100, 153, 154, and 183) was calculated. Higher PBDE levels occurred in soil on flood-prone compared to control farms (median 770 vs 280 ng/kg dry weight). These higher levels were not reflected in the grass samples indicating that PBDE contamination on soils is not transferred efficiently to grass. This observation alongside the fact that cows on flood-prone farms spend time on non-flood-prone land and are fed substantial quantities of commercial feed are reasons why higher PBDE levels were not found in milk from flood-prone farms (median 300 vs 250 ng/kg fat weight). Similar BDE47/BDE99 ratios were observed in soil and grass samples compared to the PBDE product commonly used in the UK, indicating few differences in source-pathway transfer efficiencies between congeners. The BDE47/BDE99 ratio in the milk samples was greater than those in the grass and feed indicating differential food to milk transfer efficiencies between congeners.     

Brominated flame retardants in US food

We and others recently began studying brominated flame retardant levels in various matrices in the US including human milk and other food. This paper reviews the food studies. In our studies, ten to thirteen polybrominated diphenyl ether (PBDE) congeners were measured, usually including BDE 209. All US women's milk samples were contaminated with PBDEs from 6 to 419 ng/g, lipid, orders of magnitude higher than levels reported in European studies, and are the highest reported worldwide. We compared our market basket studies of meat, fish and dairy products with other US food studies of meat and fish. US studies showed somewhat higher levels of PBDEs than reported elsewhere. Fish were most highly contaminated (median 616 pg/g), then meat (median190 pg/g) and dairy products (median 32.2 pg/g). However, unlike some European countries where fish predominates, dietary intake of PBDEs in the US is mostly from meat, then fish and then dairy products. Broiling can decrease the amount of PBDEs per serving. We also measured levels of hexabromocyclododecane (HBCD), another brominated flame retardant, in human milk. The levels are lower than PBDEs, 0.16-1.2 ng/g, similar to European levels, unlike PBDEs where US levels are much higher than European levels.     

Assessment of polybrominated diphenyl ether exposures and health risks associated with consumption of southern Mississippi catfish

Despite the growing public interest in polybrominated diphenyl ethers (PBDEs), there are relatively few studies in the published literature which characterize and quantify human intake of these compounds. In this study, PBDE concentrations were measured in southern Mississippi catfish to determine background levels, daily intake, and risk associated with the consumption of these chemicals from a primary food source for residents in this region of the United States. A total of 33 wild catfish samples were collected from five sites, and 28 farm-raised catfish samples were purchased, all of which were from locations in southern Mississippi. All samples were analyzed for 43 PBDEs (mono- through deca-congeners) using high-resolution gas chromatography-mass spectrometry. Both PBDE concentrations (sigmaPBDE ranged from 0.3 to 23.3 ng/g wet weight) and congener profiles varied by fish type and location; however, BDE congeners 47, 99, 100, 153, and 154 were the dominant contributors in all samples. The estimated daily intake of PBDEs associated with consumption of the catfish ranged from 0.03 to 1.80 ng/kg-day. Evaluation of the cancer risk for BDE 209 and the noncancer hazard for BDE congeners 47, 99, 153, and 209 indicated that health risks/hazards due to fish consumption in adults are substantially lower than risk levels generally considered to be at the U.S. EPA minimum concern level.     

Debromination of polybrominated diphenyl ether congeners BDE 99 and BDE 183 in the intestinal tract of the common carp (Cyprinus carpio)

Polybrominated diphenyl ether (PBDE) congener patterns in biota are often enriched in tetra-, penta-, and hexabrominated diphenyl ethers, which is believed to result from the use of the commercial "pentaBDE" formulation. However, our evidence suggests that debromination of PBDEs occurs within fish tissues leading to appreciable accumulation of less brominated congeners. This suggests that PBDE body burdens can reflect both direct uptake from exposure and debromination of more highly brominated congeners. We conducted two independent dietary exposure studies using the common carp (Cyprinus carpio) to trace the fate of 2,2',4,4',5-pentabromodiphenyl ether (BDE 99) and 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE 183) in fish tissues. Carp were fed food spiked with individual BDE congeners for 62 d, and depuration was monitored during the following 37 d. Significant debromination was observed, converting BDE 99 to 2,2',4,4'-tetrabromodiphenyl ether (BDE47) and BDE 183 to 2,2',4,4',5,6-hexabromodiphenyl ether (BDE 154) and another as yet unidentified hexa-BDE congener. The BDE 99 concentration rapidly declined from 400 +/- 40 ng/g ww in the food to 53 +/- 12 ng/g ww in the gut content material sampled 2.5 +/- 1 h following feeding. At least 9.5 +/- 0.8% of the BDE 99 mass in the gut was debrominated to BDE 47 and assimilated in carp tissues. In the BDE 183 exposure, approximately 17% of the BDE 183 mass was debrominated and accumulated in carp tissues in the form of two hexa-BDE congeners. In both exposure studies, the concentration of the exposure compound decreased significantly in the gut within 2.5 +/- 1 h following ingestion. This rapid decrease in the concentration of the BDE congeners could not be explained entirely by debromination to quantified products or fecal egestion. Reactions occurring within the gut transform BDE congeners to other products that may accumulate or be excreted. Further studies are needed to identify and determine the effects of these BDE metabolites.     

Consumption of fish from a contaminated lake strongly affects the concentrations of polybrominated diphenyl ethers and hexabromocyclododecane in serum

Very high concentrations of polybrominated diphenyl ethers (PBDE) have been reported in fish from Lake Mj?sa in Norway. This study was performed to examine the serum concentrations of PBDE and hexabromocyclododecane (HBCD) in consumers of fish from this lake and to investigate possible relationships between serum concentrations, self-reported fish intake and calculated total dietary PBDE exposure. Serum concentrations of the sum of the seven PBDE (BDE-28, 47, 99, 100, 153, 154 and 183) were significantly higher than those of a reference group of Norwegians eating only food with background levels of contamination (medians: 18 ng/g lipids men, 8.4 ng/g lipids women). The median dietary intake of Sum 7 PBDE was 2549 ng/day (30 ng/kg body weight/day), the highest dietary intake of PBDE reported. The contribution from fish caught from the contaminated lake comprised 98.7% of the total dietary exposure. For men, serum levels of PBDE were strongly correlated with the calculated dietary exposure, except for BDE-209. This suggests that sources other than the diet are important for human BDE-209 exposure. The median serum HBCD concentration was 4.1 and 2.6 ng/g lipids for men and women, respectively, and was also found to be associated with consumption of fish from Lake Mj?sa.     

Dietary exposure to brominated flame retardants correlates with male blood levels in a selected group of Norwegians with a wide range of seafood consumption

This study investigates dietary exposure and serum levels of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) in a group of Norwegians (n = 184) with a wide range of seafood consumption (4-455 g/day). Mean dietary exposure to Sum 5 PBDEs (1.5 ng/kg body weight/day) is among the highest reported. Since concentrations in foods were similar to those found elsewhere in Europe, this may be explained by high seafood consumption among Norwegians. Oily fish was the main dietary contributor both to Sum PBDEs and to the considerably lower HBCD intake (0.3 ng/kg body weight/day). Milk products appeared to contribute most to the BDE-209 intake (1.4 ng/kg body weight/day). BDE-209 and HBCD exposures are based on few food samples and need to be confirmed. Serum levels (mean Sum 7 PBDEs = 5.2 ng/g lipid) and congener patterns (BDE-47 > BDE-153 > BDE-99) were comparable with other European reports. Correlations between individual congeners were higher for the calculated dietary exposure than for serum levels. Further, significant but weak correlations were found between dietary exposure and serum levels for Sum PBDEs, BDE-47, and BDE-28 in males. This indicates that other sources in addition to diet need to be addressed.     

Brominated flame retardants in fish and shellfish - levels and contribution of fish consumption to dietary exposure of Dutch citizens to HBCD

In order to determine the contamination with brominated flame retardants (BFR) in fish regularly consumed by Dutch citizens, 44 samples of freshwater fish, marine fish, and shellfish were analyzed for polybrominated diphenyl ethers (PBDE), tetrabromobisphenol-A (TBBP-A) and its methylated derivative (me-TBBP-A), and hexabromocyclododecane (HBCD), including its alpha-, beta- and gamma-diastereomers. The highest BFR concentrations were found in pike-perch and eel from the highly industrialized and urbanized rivers Rhine and Meuse. The sum concentrations of BDE 28, 47, 99, 100, 153, 154, 183, 209, and brominated biphenyl (BB) 153 and HBCD (selection based on The European Food Safety Authority monitoring recommendation) ranged from below quantification limits to 17 ng/g wet weight (ww) in marine fish and in freshwater fish from 0.6 ng/g ww in pike-perch to 380 ng/g ww in eel. The BDE congener profile in all fish and shellfish samples is dominated by BDE 47, followed by BDE 99, except for eel in which BDE 100 is higher than BDE 99. BDE 209 was detected in two mussel samples, most likely due to BDE 209 contaminated particulate matter in their intestines. Total-HBCD (as determined by GC/electron capture negative ion (ECNI)-MS) was detected in 22 out of the 44 samples in concentrations between 0.20 ng/g in marine fish and 230 ng/g ww in eel. Three HBCD diastereomers were determined by HPLC/ESI-MS/MS. alpha-HBCD was the prevalent congener in most fish samples, followed by gamma-HBCD. beta-HBCD, TBBP-A and me-TBBP-A were only detected in a few samples and at low concentrations. A considerable difference was found between HBCD results obtained from GC/ECNI-MS and HPLC/ESI-MS/MS: the GC/ECNI-MS results were 4.4 times higher, according to regression analysis. There is hardly any data on human dietary exposure to HBCD available. We have estimated the fish-related dietary exposure of HBCD for the average Dutch population. The medium bound intake was estimated at 8.3 ng/day for a 70-kg person (0.12 ng/kg bodyweight/day). For this estimation, we relied mostly on HPLC/ESI-MS/MS data as we argue that these results are more accurate than those obtained by GC/ECNI-MS.     

Assessment of human exposure to polybrominated diphenyl ethers in China via fish consumption and inhalation

This study examined human exposure to polybrominated diphenyl ethers (PBDEs) associated with fish consumption and inhalation in China. The median intake of sigma7 PBDEs via human milk was 48.2 ng/day for nursing infants (0-1 years old) (a range of 23.4-99.1 ng/day). For all other age groups, the median intake of sigma11 PBDEs via fish consumption was 1.7-12.9 ng/day with a range of 0.59-56.3 ng/g. Additionally, human exposure to PBDEs via inhalation was 2.7-9.2 ng/day (a range of 0.72-108 ng/day). The median total sigma11 PBDEs intakes for nursing infants (6874 and 7372 pg/ kg b.w./day for males and females, respectively) were much higher than other age groups (215-608 pg/kg b.w./ day). No significant difference in the total PBDEs intakes was found between males and females. Of the 11 PBDEs congeners, BDE-47 was predominant in the total intake for nursing infants with a mean contribution of 38%, whereas BDE-209 was the dominant congener of total intake for other age groups, varying from 44 to 61%. Currently, the PBDEs levels in Chinese consumer fish and the total intakes of PBDEs via fish consumption were at the lower end of the global range. Compared with similar studies in other countries, however, human exposure to PBDEs via inhalation in China was relatively high. Overall, estimated daily intake of total PBDEs in the Chinese population was far below the LOAEL. However, studies are needed to further understand the fate and impact of PBDEs as PBDE-containing products are still used widely in large quantities in China.     

High postnatal exposures to polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) via breast milk in California: does BDE-209 transfer to breast milk?

Breast milk samples collected during 2003-2005 from 82 first-time mothers in 24 communities located throughout California contained levels of polybrominated diphenyl ethers (∑(tri-hexa (8))PBDEs; median = 53.3 ng/g lw, range = 9.60-1291) and polychlorinated biphenyls (∑(12)PCBs; median = 73.4 ng/g lw, range = 22.2-433) that are among the highest in the world. PBDE levels varied 100-fold. BDE-47 was the dominant PBDE congener, with levels exceeding the U.S.EPA Reference Dose (RfD) for neurodevelopmental toxicity (100 ng/kg/day) in most (60%) breast milk samples. In some samples, BDE-209 (2/82) and/or BDE-153 (5/82) were the dominant congeners, suggesting that BDE-209 can transfer to breast milk and/or break down in the mother and transfer to the nursing infant as the lower-brominated PBDEs associated with adverse effects. PBDE levels in California breast milk are approaching those of PCBs, and the trend PBDEs > PCBs may continue as PBDEs migrate from products to the indoor and outdoor environments.     

Polybrominated diphenyl ethers in watershed soils of the Pearl River Delta, China: occurrence, inventory, and fate

Soils play an important role in the distribution and biogeochemical cycling of polybrominated diphenyl ethers (PBDEs) as they are a major reservoir and sink for PBDEs due to their large sorption capacity. In this study, concentrations, compositional profiles, mass inventories, and fate of sigma9PBDEs (28, 47, 66, 100, 99, 154, 153, 138, 183) and BDE 209 were investigated in 33 surface soils, six profile soils, and three point-source polluted soils (close to e-waste dismantling sites) from the Pearl River Delta (PRD), China. The concentrations of sigma9PBDEs and BDE 209 in the surface soils ranged from 0.13 to 3.81 ng/g with an average of 1.02 ng/g and from 2.38 to 66.6 ng/g with an average of 13.8 ng/g, respectively, and ranged from 1.93 to 19.5 ng/g and from 25.7 to 102 ng/g, respectively, in the point-source contaminated soils. The PBDE compositional patterns in the surface soils indicated deca-BDE, penta-BDE, and octa-BDE products as the main sources, but those in the point-source samples suggested deca-BDE and octa-BDE technical mixtures as the dominant sources. The mass inventories of PBDEs in soils of the PRD were estimated at 3.98 and 44.4 t for sigma9PBDEs and BDE 209, respectively. The average loading of PBDEs in the soils was comparable to that in the sediments of the Pearl River Estuary, suggesting that soil erosion and surface runoff are an important mode to transport PBDEs from terrestrial sources to oceans in the PRD. Individual BDE congeners, sigma9PBDEs, and PBDE 209, were significantly correlated with total organic carbon (TOC), and a good regression (except for BDE 47) between the logarithms of TOC-normalized BDE average concentrations and their log K(ow) was also obtained, indicating that sorption of PBDEs on soil organic matter governed their spatial distribution, transportation, and fate in the soils. Predicted aqueous and gaseous concentrations of PBDEs were derived from the soil-water and soil-air partitioning models, respectively, and good agreements were obtained between the predicted and previously reported values. BDE 47 and/or 28 did not appear to follow the same trend for these models, an indication that an portion of them was likely the biodegradation byproducts in soils.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in human adipose tissue from New York

Human adipose tissue samples (n=52) collected in New York City during 2003-2004 were analyzed for the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). Concentrations of PBDEs in adipose tissues ranged from 17 to 9630 ng/g, lipid wt (median: 77; mean: 399 ng/g, lipid wt; sum all di- through hexaBDE congeners). Average PBDE concentrations in human adipose tissues from New York City were 10- to 100-times greater than those reported for European countries. A concentration of 9630 ng/g, lipid wt, found in a sample of adipose tissue, is one of the highest concentrations reported to date. PBDE 47 (2,2',4,4'-tetraBDE) was the major congener detected in human tissues, followed by PBDE congeners #99 (2,2',4,4',5-penta BDE), 100 (2,2',4,4',6-pentaBDE), and 153 (2,2',4,4',5,5'-hexaBDE). A few individuals contained PBDE 153 as the predominant congener in total PBDE concentrations, suggesting alternative exposure sources, possibly occupational. Principal component analysis of PBDE congener composition in human adipose tissues revealed the presence of five clusters, each characterized by varying composition. No significant difference was found in the concentrations of PBDEs between gender. Concentrations of PBDEs were, on average, similar to those for PCBs in human adipose tissues, and substantially higher when PBDE outliers were retained. PBDE and PCB concentrations were not correlated. PBDE concentrations did not increase with increasing age of the subjects, whereas concentrations of PCBs increased with increasing age in males but not in females in this study. These results suggest differences between PBDEs and PCBs in their sources or time course of exposure and disposition. The presence of comparable or greater concentrations of PBDEs, relative to PCBs, highlights the importance of recentvoluntary and regulatory effortsto cease production of commercial penta- and octa-BDE in North America, although these efforts do not address continuing emissions from existing sources, such as polyurethane foams.     

Exposure to PBDEs and PCDEs associated with the consumption of edible marine species

In the present study, the concentrations of PBDEs and PCDEs were determined in 14 edible marine species widely consumed by the population of Catalonia (Spain). The daily intake of PBDEs and PCDEs associated with this consumption was also determined. A total of 42 composite samples were analyzed by HRGC/HRMS. The highest PBDE levels (ng/kg wet weight) were found in salmon (2015) followed by mackerel, swordfish, and red mullet (1124, 978, and 769, respectively), while those of PCDEs (ng/kg wet weight) were detected in red mullet (7088) followed by sardine (1829), anchovy (1606), tuna (1292), and mackerel (1031). For a standard male adult, total PBDE and PCDE intakes through edible marine species were 20.8 and 39.4 ng/ day, respectively. The highest contributions to these intakes (ng/day) corresponded to the consumption of tuna (5.7), salmon (3.6), and hake (3.5) for PBDEs, and tuna (13.1), hake (7.3), and sardine (6.9) for PCDEs. Although currently there is not evidence of the dioxin-like behavior of PBDEs, further research is necessary to assess if long-term exposure to PBDEs, mainly through the diet, may mean adverse effects to humans. With respectto PCDE congeners, to establish TEF values would be of great value to evaluate human health risks.     

Determination of brominated flame retardants and brominated dioxins in fish collected from three regions of Japan

The concentrations of brominated dioxins which are polybrominated dibenzo-p-dioxins/polybrominated dibenzofurans (PBDD/DFs) and mono-bromo polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) were investigated in a total of 45 fish samples collected from three regions in Japan. In the brominated dioxins, 1,2,3,4,6,7,8-heptabromodibenzofuran (HpBDF) was the most abundant congener, and it was found in seven fish samples at 0.10-25.6 pg/g wet weight (ww). The highest concentration of 1,2,3,4,6,7,8-HpBDF was found in the pike eel. Regarding other congeners, 2,3,7,8-tetrabromodibenzo-p-dioxin was detected in the sea bream at 0.02 pg/g ww, and 2,3,7,8-tetrabromodibenzofuran was detected in the conger eel at 0.03 pg/g ww. 3-Bromo-2,7,8-trichlorodibenzofuran was detected in the Sardinella zunasi and the conger eel at 0.01 pg/g ww and 0.02 pg/g ww, respectively. Using toxic equivalency factors of chlorinated dioxins, we calculated the PBDD/DFs concentrations of these fish samples at 0.001-0.256 pg TEQ/g ww. PBDEs were detected in all of the fish samples. The concentrations of total PBDEs were 0.01-2.88 ng/g ww. The seerfish and the yellowtail containd PBDEs in high concentrations. The most dominant congener in most of the fish was 2,2',4,4'-tetrabromo diphenyl ether. TBBPA was detected in 29 fish samples at 0.01-0.11 ng/g ww. The mean level of TBBPA was about one-tenth or less of the total level of PBDEs. A good correlation was obtained between total PBDEs and fat content. On the other hand, no correlation was obtained between TBBPA and fat content. The daily intakes from fish were estimated to be 0.58 ng/kg body weight (bw)/day for total PBDEs, 0.03 ng/kg bw/day for TBBPA, and 0.01 pg TEQ/kg bw/day for brominated dioxins in the case assuming that the average bw of a Japanese adult person is 50 kg and that the average fish consumption is 82 g/day. For PBDEs, the provisionally calculated value was much less than the lowest observed adverse effect level value (1 mg/kg bw/day). For brominated dioxins, the daily intake was at a very low level compared with the Japanese daily intake of polychlorinated dioxins from fish. Even if the value of PBDD/DFs is added to the amount of chlorinated dioxin exposure, it was estimated that it is less than the tolerable daily intake (4 pg TEQ/kg bw/day) in Japan.     

Dietary accumulation efficiencies and biotransformation of polybrominated diphenyl ethers in farmed Atlantic salmon (Salmo salar).

The consumer safety of farm-raised salmon could be improved by determining the transfer efficiency of hazardous pollutants from fish feed to the salmon. A controlled feeding trial for 30 weeks was carried out to investigate the transfer of polybrominated diphenyl ethers (PBDEs) in Atlantic salmon (Salmo salar). Using three feed concentrations, an average of 95% of the total PBDE content of feed accumulated in whole salmon. Skinned fillet accumulated 42-59% of the PBDE intake. Equal partitioning according to the lipid content of the tissue was demonstrated. The formation of less brominated PBDEs via preferential debromination from the meta-position was thought to explain the exceptional accumulation efficiencies of BDE 47, BDE 66, BDE 75, BDE 119 and BDE 183 that were either >100% or else increasing with the exposure dose. Monitoring of a larger number of PBDE congeners is recommended to verify the biotransformation routes. The PBDE concentration in salmon of different ages, fed on a known concentration of PBDEs in fish feed, could be predicted by using the accumulation efficiencies determined in this study.