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.     

Partitioning and bioaccumulation of PBDEs and PCBs in Lake Michigan

Water from Lake Michigan and fish from all five Great Lakes have been sampled and analyzed for a suite of six polybrominated diphenyl ether (PBDE) congeners and 110 polychlorinated biphenyl congeners (PCBs). The Lake Michigan dissolved phase PBDE congener concentrations (0.2 to 10 pg/L) are similar to dissolved phase PCB congener concentrations (nondetected to 13 pg/L). Partitioning of PBDEs between the particulate and dissolved phases exhibits behavior similar to that of PCBs. Organic-carbon-normalized water-particle partition coefficients (log K(OC)s) ranged from 6.2 to 6.5. Lake trout are depleted in BDE-99 relative to dissolved phase concentrations, and in contrast to what is expected from the PCB congener patterns. This reflects suspected debromination of BDE-99 in the food web of Lake Michigan. A regression of the log of the bioaccumulation factor (BAF) and the log of the octanol-water partition coefficent (K(OW)) indicated a positive relationship for both PCB congeners and PBDE congeners. BDE-99 does not appear to followthe same trend, a further indication that it is subject to biotransformation. Using the PBDE BAFs for Lake Michigan and the PBDE fish concentrations from the other Great Lakes it is expected that the dissolved phase concentrations of congeners in the other lakes would range from 0.04 to approximately 3 pg/L.     

Concentrations and spatial variations of polybrominated diphenyl ethers and several organochlorine compounds in fishes from the northeastern United States

Fish from four lakes, two small lakes in the northeastern United States and two of the Great Lakes, were analyzed to determine the concentrations and spatial variations of polybrominated diphenyl ethers (PBDE) in this region. Three of the lakes were considered to have background levels of PBDEs; one lake was close to a suspected source. The PBDE concentrations were compared to organochlorine pesticide and PCB concentrations. Age and trophic position did not influence the organohalogen concentrations in the fish collected from the four locations. At the three background locations, the sum of PBDE concentrations ranged from 6.9 +/- 1.4 to 18 +/- 1 ng/g wet weight, or 150 +/- 9 to 300 +/- 80 ng/g lipid, and these values were similar to those of some of the organochlorine pesticides, such as total chlordane, but lower than sum of PCB concentrations. At the lake near the suspected source, the sum of PBDE concentration was 65 +/- 8 ng/g wet weight, or 2,400 +/- 600 ng/g lipid, and it exceeded the sum of PCB concentration. The hexabrominated congeners made up 43% of the total mass of PBDEs at this lake, and 7% at the background locations. Fish to sediment concentration ratios indicated that the tetra- through hexa-substituted congeners have a similar bioavailability, while the deca-substituted congener does not seem to be bioavailable at all.     

PCB congeners in Lake Michigan coho (Oncorhynchus kisutch) and chinook (Oncorhynchus tshawytscha) salmon

We determined PCB congener concentrations in coho and chinook salmon collected in two Lake Michigan tributaries during the fall of 1996. Chinook salmon were larger than coho salmon and contained higher concentrations of the 78 PCB congeners we detected. There were no differences between male and female chinook or coho salmon in size or their PCB concentrations. Among individual fish, we found little evidence for a relationship between congener concentrations and percent lipid; however, congener concentrations did show a generally positive relationship with salmon size. Fish and macroinvertebrate congener concentrations are clearly related, and PCB congeners biomagnify approximately 20-30-fold as they flow from macroinvertebrates, two trophic levels below salmon, to the salmon. Slopes of regressions of salmonid congener concentrations on macroinvertebrate congener concentrations within homologs indicated that the degree of biomagnification generally increased with the degree of congener chlorination, although this pattern was much stronger for Mysis than for Diporeia. Log Kow and categorical variables for coplanar and "toxic" PCBs were not significant additional model terms, indicating that bioaccumulation of PCB congeners was not statistically related to these physicochemical attributes of the PCBs. The distribution of homologue PCBs shifts from a distinct predominance of hexachlorobiphenyls in macroinvertebrates to pentachlorobiphenyls and hexachlorobiphenyls in the salmon.     

Investigation of selected persistent organic pollutants in farmed Atlantic salmon (Salmo salar), salmon aquaculture feed,and fish oil components of the feed

There is extensive literature documenting the bioaccumulation of persistent organic pollutants in the marine environment, but relatively little data are available on contamination pathways in aquaculture systems such as that for farmed salmon. In recent years,the salmon industry has grown significantly in Europe. This study reports on the determination of a wide range of polychlorinated biphenyls (PCBs), organochlorine pesticides, and polybrominated diphenyl ethers (PBDEs) in farmed and wild European Atlantic salmon fish, aquaculture feeds, and fish oils used to supplement the feeds. The study confirms previous reports of relatively high concentrations of PCBs and indicates moderate concentrations of organochlorine pesticides and PBDEs in farmed Scottish and European salmon. Concentrations of the selected persistent organic pollutants varied among the samples: PCBs (salmon, 145-460 ng/g lipid; salmon feeds, 76-1153 ng/g lipid; fish oils, 9-253 ng/g lipid), S DDTs (salmon, 5-250 ng/g lipid; salmon feeds, 34-52 ng/g lipid; fish oils, 11-218 ng/g lipid), and PBDEs (salmon, 1-85 ng/g lipid: salmon feeds, 8-24 ng/g lipid; fish oils, ND-13 ng/g lipid). Comparison of the samples for all groups of contaminants, except for HCHs, showed an increase in concentration in the order fish oil < feed < salmon. Homologue profiles were similar, with an increase in contribution of hepta- and octa-PCBs in the fish, and profiles of DDTs were similar in all three types of samples. With a constant contribution to the total PCB content, the ICES 7 PCBs appear to be reliable predictors of the PCB contamination profile through all the samples. For PBDEs, BDE 47 dominated the profiles, with no significant difference in the PBDE profiles for the three matrixes. Samples with higher PCB contents generally showed higher levels of the pesticide residues, but this was not the case with the PBDEs, indicating the existence of different pollution sources.     

A preliminary comparison of polybrominated diphenyl ether concentrations relative to lipid content and to levels of dioxins and dioxin-like polychlorinated biphenyls in Norwegian farmed Atlantic salmon (Salmo salar)

Polybrominated diphenyl ethers (PBDEs) are environmental contaminants structurally similar to polychlorinated biphenyls (PCBs), and correlations between PBDE concentrations and concentrations of lipid, PCBs, dioxins and furans in feed and farmed Atlantic salmon filet indicate PBDEs may be derived from similar sources. PBDE concentrations (3.9 ± 0.6 ng g^?1 wet wt) in farmed Atlantic salmon correlated well with lipid content and these other halogenated contaminants, however, lower concentrations of PBDEs (1.6 ± 0.3 ng g^?1 wet wt) showed no correlation. Possible explanations for the non‐linear behaviour of PBDE concentrations in Atlantic salmon are discussed.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in a marine foodweb of coastal Florida

Nine species of marine fish, including teleost fishes, sharks, and stingrays, and two species of marine mammals (dolphins) collected from Florida coastal waters were analyzed for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) to evaluate biomagnification factors (BMF) of these contaminants in a coastal foodweb. In addition, bottlenose dolphins and bull sharks collected from the Florida coast during the 1990s and the 2000s were analyzed for evaluation of temporal trends in PBDE and PCB levels in coastal ecosystems. Mean concentrations of PBDEs in muscle tissues of teleost fishes ranged from 8.0 ng/g, lipid wt (in silver perch), to 88 ng/g, lipid wt (in hardhead catfish), with an overall mean concentration of 43 +/- 30 ng/g, lipid wt. Mean concentrations of PBDEs in muscle of sharks ranged from 37.8 ng/g, lipid wt, in spiny dogfish to 1630 ng/g, lipid wt, in bull sharks. Mean concentrations of PBDEs in the blubber of bottlenose dolphins and striped dolphins were 1190 +/- 1580 and 660 ng/g, lipid wt, respectively. Tetra-BDE 47 (2,2',4,4'-) was the major congener detected in teleost fishes and dolphin samples, followed by BDE-99, BDE-153, BDE-100, and BDE-154. In contrast, BDE-209 was the most abundant congener in sharks. Concentrations of PBDEs and PCBs in dolphins and sharks were 1-2 orders of magnitude greater than those in lower trophic-level fish species, indicating biomagnification of both of these contaminants in the marine foodweb. Based on the analysis of sharks and dolphins collected over a 10-year period, an exponential increase in the concentrations of PBDEs and PCBs has occurred in these marine predators. The doubling time of PBDE and PCB concentrations was estimated to be 2-3 years for bull sharks and 3-4 years for bottlenose dolphin.     

Polybrominated diphenyl ethers in the sediments of the Great Lakes. 2. Lakes Michigan and Huron

Sediment cores were taken in 2002 in Lakes Michigan and Huron at six locations. A total of 75 samples were characterized, dated using 210Pb, and analyzed for 10 congeners of polybromodiphenyl ether (PBDE) including BDE209, as well as 39 congeners of polychlorinated biphenyls (PCBs). The concentrations of nine tri- through hepta-BDE congeners (Sigma9PBDE) in the surficial sediments range from 1.7 to 4 ng g(-1) for Lake Michigan and from 1.0 to 1.9 ng g(-1) for Lake Huron, on the basis of the dry sediment weight. The Sigma9PBDEs fluxes to the sediment around the year 2002 are from 36 to 109 pg cm(-2) yr(-1) in Lake Michigan and from 30 to 73 pg cm(-2) yr(-1) in Lake Huron, with spatial variations in both lakes. The flux of BDE209 ranges from 0.64 to 2.04 ng cm(-2) yr(-1) and from 0.67 to 1.41 ng cm(-2) yr(-1) in Lake Michigan and Lake Huron, respectively. Dramatic increases in PBDE concentrations and fluxes upward toward the sediment surface and the present time are evident at all locations. The inventory of PBDEs in both lakes appears to be dependent upon latitude and the proximity to populated areas, implying that north-bound air plumes from urban areas are the major sources of PBDEs found in the lake sediments at locations away from the shores. Heavier congeners are more abundant in the sediments than in air and fish samples in the region. BDE209 is about 96% and 91% of the total PBDEs on a mass basis in Lake Michigan and Lake Huron, respectively; both are higher than the 89% found in Lake Superior, although a t test shows that the value for Lake Huron is not statistically different from that for Lake Superior at the 95% confidence level.     

Resident fishes display elevated organic pollutants in salmon spawning streams of the great lakes

Pacific salmon (Oncorhynchus spp.) can transport bioaccumulated organic pollutants to stream ecosystems where they spawn and die. We quantified PCBs, DDE, and PBDEs in resident fishes from 13 Great Lakes tributaries to assess biotransport of pollutants associated with introduced Pacific salmon. Resident fishes sampled from salmon spawning reaches had higher mean pollutant concentrations than those from upstream reaches lacking salmon (93.5 and 4.1 μg·kg(-1) [PCB], 24.0 and 3.1 μg·kg(-1) [DDE], 8.5 and 1.0 μg·kg(-1) [PBDE], respectively), but differences varied substantially among lake basins. In Lake Michigan tributaries, PCB concentrations in resident fishes from salmon reaches were over four times higher than those from salmon reaches in Lake Huron and over 30 times higher than those from Lake Superior. Moreover, resident fish pollutant concentrations were better explained by pollutant inputs from salmon (μg·m(-2); R(2) = 0.76 [PCB], 0.64 [DDE], 0.64 [PBDE]) than by land development/agriculture, watershed area, resident fish species, body length, or lipid content. These results suggest that pollutant dispersal to stream ecosystems via biotransport is an often overlooked consequence of salmon stocking and historical food web contamination in the Great Lakes. Our findings have implications for Great Lakes management, including dam removal and wildlife conservation.     

Snapping turtles (Chelydra serpentina) as bioindicators in Canadian areas of concern in the Great Lakes Basin. 1. Polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in eggs

We examined the concentrations and spatial patterns of congeners of PBDEs, PCBs, and organochlorine pesticides in snapping turtle (Chelydra serpentina) eggs from Areas of Concern (AOCs) on the Canadian shores of Lake Ontario, St. Lawrence River, and connecting channels. Eggs from Lyons Creek (Niagara River AOC) reflected a local PCB source over a range of 7.5 km (3.2-10.8) from the Welland Canal. PCB contamination in eggs declined with increasing distance from the Welland Canal, whereas the relative contribution of congeners associated with Aroclor 1248/1254 increased with sigma PCB concentrations. Compared to turtle eggs from other sites in Lake Erie and Lake Ontario, eggs from Lyons Creek and Snye Marsh had PCB congener patterns that reflected a strong contribution from Aroclor 1254. PCBs in the eggs were associated with industrial sources and reflected the composition of different Aroclor technical mixtures. Organochlorine pesticides in eggs tended to be highest at Hamilton Harbour and Bay of Quinte AOCs, and were dominated by DDE, sigma chlordane, and mirex. In contrast, PBDE congener patterns in turtle eggs resembled PentaBDE technical formulations regardless of absolute concentrations or location, and were largely associated with urban environments.     

Brominated flame retardants in polar bears (Ursus maritimus) from Alaska, the Canadian Arctic, East Greenland, and Svalbard

Polybrominated diphenyl ethers (PBDEs) were determined in adipose tissue of adult and subadult female polar bears sampled between 1999 and 2002 from sub-populations in Arctic Canada, eastern Greenland, and Svalbard, and in males and females collected from 1994 to 2002 in northwestern Alaska. Only 4 congeners (BDE47, 99, 100, and 153) were consistently identified in all samples. BDE47 was the major PBDE congener representing from 65% to 82% of the sum (sigma) PBDEs. Age was not a significant covariate for individual PBDEs or sigmaPBDE. Higher proportions of BDE 99, 100, and 153 were generally found in samples from the Canadian Arctic than from Svalbard or the Bering-Chukchi Sea area of Alaska. Geometric mean sigmaPBDE concentrations were highest for female polar bear fat samples collected from Svalbard (50 ng/g lipid weight (lw)) and East Greenland (70 ng/g lw). Significantly lower sigmaPBDE concentrations were found in fat of bears from Canada and Alaska (means ranging from 7.6 to 22 ng/g lw).     

Polybrominated diphenyl ethers in the sediments of the Great Lakes. 3. Lakes Ontario and Erie

Sediment cores were taken in 2002 in Lakes Ontario and Erie at four locations. A total of 48 sediment samples were characterized, dated using 210Pb, and analyzed for 10 congeners of polybrominated diphenyl ethers (PBDEs) including BDE209 as well as 39 congeners of polychlorinated biphenyls (PCBs). The surficial concentrations of nine tri- through hepta-BDE congeners (sigma9PBDE) are 4.85 and 6.33 ng g(-1), at sampling sites ON40 and ON30 in Lake Ontario, and 1.83 and 1.95 ng g(-1) at ER37 and ER09 in Lake Erie, respectively, based on dry sediment weight. The surficial BDE209 concentrations are 242 and 211 ng g(-1) at ON40 and ON30 and 50 and 55 ng g(-1) at ER37 and ER09. The sigma(9-) PBDEs fluxes to the sediment around 2002 are 147 and 195 pg cm(-2) year(-1) at ON40 and ON30 and 136 and 314 pg cm(-2) year(-1) at ER37 and ER09, respectively. The fluxes of BDE209 are 6.5 and 7.3 ng cm(-2) year(-1) at ON30 and ON40 and 3.7 and 8.9 ng cm(-2) year(-1) at ER37 and ER09, respectively. Dramatic increases in PBDE concentrations and fluxes upward toward the sediment surface and the present time are evident at both locations in Lake Ontario, while PCBs concentrations peak in the middle of sediment cores around the dated time of 1970s and 1960s. For both locations of Lake Erie, the increasing trends of both PBDEs and PCBs from the bottom to the surficial segments were distorted by sediment mixing. BDE209 is the most abundant congener among PBDEs in the sediments, constituting about 96 and 91% of the total PBDEs on mass basis in Lakes Ontario and Erie, respectively.     

Brominated flame retardants in sediment cores from Lakes Michigan and Erie

The history of polybrominated diphenyl ethers (PBDEs) and the major polybrominated biphenyl congener (BB-153) was studied in dated sediment cores taken from Lakes Michigan and Erie. The surficial concentration of total PBDE (65 [corrected] ng/g dry weight) in Lake Michigan was about 1.6 [corrected] times higher than that in Lake Erie (40 ng/g) and about 5 times higher than that [corrected] in Lake Superior (approximately 12 ng/g). The concentrations of total PBDEs in these sediments have increased rapidly, with doubling times of 5-10 years, reflecting the increasing market demand for these flame retardants over the last 30 years. BDE-209 was found to be the predominant congener in both sediment cores, making up approximately 95% [corrected] of the total PBDE load. The inventories of total PBDEs in Lakes Michigan and Erie were both [corrected] 40 ng/cm2 [corrected] The total burdens of these compounds in the sediment of Lakes Michigan and Erie were 23 [corrected] and 10 metric tons, respectively. We estimate [corrected] the total burden of these compounds in all of the Great Lakes is on the order of 100 [corrected] tons. In both lakes, BB-153 was found to increase rapidly during the 1970s and to peak around 1980.     

Polychlorinated dioxins, furans, and biphenyls, and polybrominated diphenyl ethers in a U.S. meat market basket and estimates of dietary intake

Persistent environmental contaminants including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), non-ortho-polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were analyzed in 65 meat samples collected from supermarkets across the U.S. in 2001. The samples included hamburger, sirloin steaks, pork chops, bacon, and whole chickens from nine different cities. The average PCDD/F/non-ortho-PCB toxic equivalency (TEQ) for all the samples was 0.55 pg/g of lipid (nd (nondetect) = DL (detection limit)/2) with a range from nondetectable to 3.21 pg/g of lipid. For PBDEs, eight congeners were routinely found in the meat samples with an average sum of 1.71 ng/g of lipid (nd = DL/2) and a range from nondetectable to 16.6 ng/g of lipid. While average TEQs were similar to recent values reported in Europe and Asia, the sums of PBDEs in chicken and pork were 3-20 times higher than levels reported in Spain and Japan for these foods. The presence of a few outliers raised the average PBDE sums and indicated that isolated sources of contamination may exist that, if identified, could be removed from the U.S. animal production chain. Using these TEQ and PBDE values and USDA food consumption data, the estimated dietary intake ranges from meat products were 5.3-16.0 pg TEQ and 14.9-44.7 ng of PBDEs/d or 0.1-0.3 pg TEQ and 0.3-0.5 (ng of PBDEs/kg of body mass)/d for an average individual, similar to intakes in other countries.     

Polybrominated diphenyl ethers in the sediments of the Great Lakes. 1. Lake Superior

Sediment cores were taken in 2001 and 2002 in Lake Superior at six locations away from lakeshores and segmented at 0.5-5 cm intervals. The year of sediment deposition was estimated for each segment of four cores using the 210Pb dating technique. Samples were Soxhlet-extracted and cleaned up by silica gel fractionation, and the concentrations of 10 polybrominated diphenyl ethers (PBDEs) and 19 polychlorinated biphenyls (PCBs) were measured by GC-MS in SIM mode. In contrast to recent declining or level-off trends in PCB fluxes, the sedimentary records of PBDEs generally show a significant increase in recent years. The load of total PBDEs to Lake Superior was estimated to be 2-6 metric tons, and the current loading rate was about 80-160 kg yr(-1). With the exclusion of decabromodiphenyl ether (BDE209), the surficial concentration of sumPBDE (sum of 9 congeners) ranged from 0.5 to 3 ng g(-1), and the current sumPBDEs flux was 8-31 pg cm(-2) yr(-1). The concentrations of BDE209 were about an order of magnitude higher than the sum of other congeners, comprising 83-94% of the total PBDE inventory in the sediments. Among the other nine PBDEs detected, congeners 47 and 99 were the most abundant, and congeners 100, 153, 154, and 183 were also detected in all the cores. Congener analysis demonstrated that the pattern of PBDEs in Lake Superior sediments differs from those in air and fish.     

Body burdens of persistent halogenated compounds during different development stages of anadromous brown trout (Salmo trutta)

Polychlorinated biphenyls (PCBs), DDTs, and polybrominated diphenyl ethers (PBDEs) were followed through the five life stages of a wild population of anadromous brown trout and related to variations in lipid content and exposure situations. Anadromous brown trout exhibits great variations in lipid content during its life cycle in the freshwater and marine environments. The results indicated substantial differences in PBDE and organochlorine exposure, with apparently more recent sources of PBDEs in the freshwater environment relative to the marine environment. Lipid and contaminant transfer were not always identical: The concentrations of PCBs, DDTs, and PBDEs (ng/g lipid weight) were about 15 times lower in the eggs compared to the muscle of their mother (e.g., 823 ng PCB/g Iw vs. 12,565 ng PCB/g lw, respectively). During the starving period from maiden to spawning trout the contaminant load increased by a higher factor than the lipid use. The data suggest a decoupling between lipid content and organohalogen concentrations for anadromous brown trout, which may contribute positively to reduce any potential negative effects of the transferred contaminants on eggs and fry.     

Remarkable findings concerning PBDEs in the terrestrial top-predator red fox (Vulpes vulpes)

In the present study, we have analyzed muscle, liver, and adipose tissue of 33 red foxes from Belgium for their content of polybrominated diphenyl ethers (PBDEs). Median sums of seven tri- to hepta-BDEs (BDE 28, BDE 47, BDE 99, BDE 100, BDE 153, BDE 154, and BDE 183) were 2.2, 2.4, and 3.4 ng/g lipid weight in adipose tissue, liver, and muscle, respectively. These levels were lower than those found in various species of voles and mice, the main prey species of the red fox. This is probably related to the high capacity of the foxes to metabolize and eliminate lower brominated congeners. BDE 209 generally dominated the PBDE congener profiles in the red fox samples. In samples containing BDE 209, this congener contributed, on the average, approximately 70% to the total PBDE content. BDE 209 was measured in concentrations as high as 760 ng/g lipid weight in the liver, but the detection frequency was not more than 40%. In animals with the highest BDE 209 levels, this congener was detected in muscle, liver, as well as in adipose tissue. Other abundant congeners were BDE 153 and BDE 47, which prevail in other terrestrial species. The particular PBDE congener profile observed in the red fox resembles that seen in grizzly bears from Canada, but differs from those previously reported for terrestrial avian species. Our data confirms unambiguously that BDE 209 does bioaccumulate in terrestrial top predators, such as the red fox.     

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.     

PCBs, PCDD/Fs, and organochlorine pesticides in farmed Atlantic salmon from Maine, eastern Canada, and Norway, and wild salmon from Alaska

Farmed Atlantic salmon (Salmo salar) from Maine and eastern Canada, wild Alaskan Chinook salmon (Oncorhynchus tshawytscha), and organically farmed Norwegian salmon samples were analyzed for the presence of polychlorinated biphenyls (PCBs), dioxin-like PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-p-furans (PCDFs), and chlorinated pesticides. PCDD and PCDF congeners were not detected in > 80% of the samples analyzed. Total PCB concentrations (7.2-29.5 ng/g, wet weight, ww) in the farmed salmon were significantly higher than those in the wild Alaskan Chinook samples (3.9-8.1 ng/g, ww). Concentrations of PCBs, WHO PCB TEQs, and chlorinated pesticides varied significantly by region. PCB and WHO PCB TEQ concentrations in farmed salmon from eastern Canada were lower than those reported in samples collected two years earlier, possibly reflecting recent industry efforts to lower contaminant concentrations in feed. Organically farmed Norwegian salmon had the highest concentrations of PCBs (mean: 27 ng/g, ww) and WHO PCB TEQs (2.85 pg/g,ww); their TEQ values are in the higher range of those reported in farmed salmon from around the world. Removal of skin from salmon fillets resulted in highly variable reductions of lipids and contaminants, and in some skin-off samples, contaminant levels were higher, suggesting that skin removal does not protect the consumer from health risks associated with consumption of farmed salmon.     

Sources, emissions, and fate of polybrominated diphenyl ethers and polychlorinated biphenyls indoors in Toronto, Canada

Indoor air concentrations of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) measured in 20 locations in Toronto ranged 0.008-16 ng·m(-3) (median 0.071 ng·m(-3)) and 0.8-130.5 ng·m(-3) (median 8.5 ng·m(-3)), respectively. PBDE and PCB air concentrations in homes tended to be lower than that in offices. Principal component analysis of congener profiles suggested that electrical equipment was the main source of PBDEs in locations with higher concentrations, whereas PUF furniture and carpets were likely sources to locations with lower concentrations. PCB profiles in indoor air were similar to Aroclors 1248, 1232, and 1242 and some exterior building sealant profiles. Individual PBDE and PCB congener concentrations in air were positively correlated with colocated dust concentrations, but total PBDE and total PCB concentrations in these two media were not correlated. Equilibrium partitioning between air and dust was further examined using log-transformed dust/air concentration ratios for which lower brominated PBDEs and all PCBs were correlated with K(OA). This was not the case for higher brominated BDEs for which the measured ratios fell below those based on K(OA) suggesting the air-dust partitioning process could be kinetically limited. Total emissions of PBDEs and PCBs to one intensively studied office were estimated at 87-550 ng·h(-1) and 280-5870 ng·h(-1), respectively, using the Multimedia Indoor Model of Zhang et al. Depending on the air exchange rate, up to 90% of total losses from the office could be to outdoors by means of ventilation. These results support the hypotheses that dominant sources of PBDEs differ according to location and that indoor concentrations and hence emissions contribute to outdoor concentrations due to higher indoor than outdoor concentrations along with estimates of losses via ventilation.