Asian Mussel Watch Program: contamination status of polybrominated diphenyl ethers and organochlorines in coastal waters of Asian countries

Mussel samples were used in this study to measure the levels of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in the coastal waters of Asian countries like Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, the Philippines, and Vietnam. PBDEs were detected in all the samples analyzed, and the concentrations ranged from 0.66 to 440 ng/g lipid wt. Apparently higher concentrations of PBDEs were found in mussels from the coastal waters of Korea, Hong Kong, China, and the Philippines, which suggests that significant sources of these chemicals exist in and around this region. With regard to the composition of PBDE congeners, BDE-47, BDE-99, and BDE-100 were the dominant congeners in most of the samples. Among the OCs analyzed, concentrations of DDTs were the highest followed by PCBs > CHLs > HCHs > HCB. Total concentrations of DDTs, PCBs, CHLs, and HCHs in mussel samples ranged from 21 to 58 000, 3.8 to 2000, 0.93 to 900, and 0.90 to 230 ng/g lipid wt., respectively. High levels of DDTs were found in mussels from Hong Kong, Vietnam, and China; PCBs were found in Japan, Hong Kong, and industrialized/urbanized locations in Korea, Indonesia, the Philippines, and India; CHLs were found in Japan and Hong Kong; HCHs were found in India and China. These countries seem to play a role as probable emission sources of corresponding contaminants in Asia and, in turn, may influence their global distribution.     

Comparison of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in Lake Michigan salmonids

Polybrominated diphenyl ethers (PBDEs) have been used extensively over the past two decades as flame retardants in most types of polymers. Many measurements of PBDEs in various environmental matrices from Sweden, Holland, Japan, and elsewhere have been reported, but few measurements are available for North America. PBDEs in 21 coho and chinook salmon taken from Lake Michigan tributaries in 1996 were measured for this study. The salmon samples were extracted and initially analyzed for polychlorinated biphenyl (PCB) congeners. It was demonstrated for these samples that the same extract fraction contains PBDEs. Six PBDE congeners were observed in all 21 samples, and the rank order of concentration of these congeners was similar to that in commercial mixtures of PBDEs. The average concentration across all samples of the sum of PBDE congeners was 80.1 ng/g of wet weight or 2,440 ng/g of lipid. This is much less than the average sum PCB concentration (1,450 ng/g of wet weight; 43,100 ng/g of lipid). However, the average concentration of the most abundant PBDE congener (IUPAC BDE-49: 52.1 ng/g wet, 1,590 ng/g of lipid) was about one-third of the average concentration of the most abundant PCB congener (IUPAC CB-153: 149 ng/g wet, 4,550 ng/g of lipid). On the basis of an extensive literature survey, the concentrations of PBDEs reported here are among the highest in the world for salmon in open waters. The concentrations of PBDEs and PCBs are both correlated with fish length and mass, but not with lipid content. The concentrations of PBDEs and PCBs are highly correlated in individual fish, implying that PBDEs are as prevalent as PCBs in Lake Michigan.     

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.     

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 organochlorines in archived northern fur seal samples from the Pacific coast of Japan, 1972-1998

The present study clearly indicated possible prolonged and chronic marine pollution by polybrominated diphenyl ethers (PBDEs) unless the international regulatory measures are reinforced substantially. Fat tissues of female northern fur seals (Callorhinus ursinus), collected at 10 time periods between 1972 and 1998 from the Pacific coast of northern Japan, were analyzed for PBDEs and organochlorine compounds (OCs). PCBs and DDTs were the predominant contaminants in the fur seal samples. PBDEs were detected in all the samples analyzed, the values ranging from 0.33 to 100 ng/g lipid wt. with predominance of BDE-47. The lowest PBDE levels were in the fur seals collected in 1972, with the peak concentration around 1991-1994 and then decreased to about 50% in 1997-1998. Compositions of higher brominated congeners increased since 1972, while some lower brominated congeners decreased, implying a change in the pattern of use, particularly the increased use of highly brominated diphenyl ethers during 1972-1998. In the meantime, PCB compositions in fur seals showed no temporal variation, suggesting a continuous input of PCBs into the marine environment in significant quantities. As peak concentrations of PBDEs occurred later than OCs, it is essential to follow up the patterns of PBDEs pollution that may be of great concern in the future. To our knowledge, this is the first report on the contamination by PBDEs in marine mammals from the Asia-Pacific waters.     

Trophodynamics of polybrominated diphenyl ethers in the marine food web of Bohai Bay, North China

Polybrominated diphenyl ethers (PBDEs) are of great environmental concern due to the exponential increase of the concentrations in the environment, especially in high trophic level organisms, and the trophodynamics of these chemicals in aquatic food webs is an important criterion for assessing their ecological risk. This study analyzed 13 PBDEs in the zooplankton, five invertebrate species, six fish species, and one marine bird species collected from Bohai Bay. PBDE concentrations in organisms from Bohai Bay (sigmaPBDEs: 0.15-32.8 ng/g lipid weight) were low compared with other marine organisms worldwide, and BDE-47 wasthe predominant compound in most samples,followed by BDE-28, BDE-99/BDE-100, and BDE-119. Correlation between lipid-normalized concentrations of PBDEs, and trophic levels determined by stable nitrogen isotope technologies confirmed that PBDEs were biomagnified in the marine food web. Significantly positive relationships were found fortotal PBDEs and four PBDE compounds (BDE-28, BDE-47, BDE-100, and BDE-119), and their trophic magnification factors (TMFs) were 3.53, 3.57, 7.24, 3.23, and 2.60, respectively. The concentration ratios between congeners (BDE-99/BDE-100 and BDE-99/BDE-47) were found to decrease with increasing trophic levels, suggesting that trophic-level-dependent concentrations ratios between BDE-99 and BDE-100 would be contributed by trophic level-dependent biotransformation between BDE-99 and BDE-47, and therefore resulting in the dominance of BDE-100 compared with BDE-99 and the relatively high trophic magnification of BDE-47 in the marine food web.     

Polybrominated diphenyl ethers, hydroxylated polybrominated diphenyl ethers, and measures of thyroid function in second trimester pregnant women in California

Prenatal exposure to polybrominated diphenyl ethers (PBDEs) may disrupt thyroid function and contribute to adverse neurodevelopmental outcomes. We conducted a pilot study to explore the relationship between serum concentrations of lower-brominated PBDEs (BDE-17 to -154), higher-brominated PBDEs (BDE-183 to -209), and hydroxylated PBDE metabolites (OH-PBDEs) with measures of thyroid function in pregnant women. Concentrations of PBDEs, OH-PBDEs, thyroid-stimulating hormone (TSH), total thyroxine (T(4)), and free T(4) were measured in serum samples collected between 2008 and 2009 from 25 second trimester pregnant women in California. Median concentrations of lower-brominated PBDEs and OH-PBDEs were the highest reported to date in pregnant women. Median concentrations of BDE-47 and the sum of lower-brominated PBDEs (ΣPBDE(5)) were 43.1 ng/g lipid and 85.8 ng/g lipid, respectively, and the sum of OH-PBDEs (ΣOH-PBDE(4)) was 0.084 ng/mL. We observed a positive association between the weighted sum of chemicals known to bind to transthyretin (ΣTTR binders) and TSH levels. We also found positive associations between TSH and ΣPBDE(5), ΣOH-PBDE(4), BDE-47, BDE-85, 5-OH-BDE47, and 4'-OH-BDE49, and an inverse association with BDE-207. Relationships with free and total T(4) were weak and inconsistent. Our results indicate that PBDE exposures are elevated in pregnant women in California and suggest a relationship with thyroid function. Further investigation is warranted to characterize the risks of PBDE exposures during pregnancy.     

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.     

Exposure of electronics dismantling workers to polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in South China

In P.R. China, electronic waste (e-waste) from across the world is dismantled and discarded. Concentrations of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were measured in serum from residents of an e-waste dismantling region (Guiyu, South China), where 80% of families work in e-waste recycling, and compared to a matching cohort from a nearby region where the fishing industry dominates (Haojiang). Serum concentrations of PBDEs and OCPs, but not PCBs, were significantly different in the two regions: the median sigmaPBDE concentration was 3 times higher in Guiyu than Haojiang, whereas the opposite was true for dichloro-diphenyl-trichloroethane (DDT). PBDEs typically accounted for 46% of the total organohalogen chemicals in samples from Guiyu, but 8.7% in Haojiang. The median BDE-209 concentration in Guiyu was 50-200 times higher than previously reported in occupationally exposed populations. The highest BDE-209 concentration was 3100 ng/g lipid, the highest yet reported in humans. Serum PBDE concentrations did not correlate with PCBs or OCPs, whereas PCBs and OCPs showed positive correlations, suggesting that sources of PBDEs to humans are different from PCBs and OCPs. The levels of PBDEs in individuals from Haojiang are possibly related to the recycling activity at Guiyu, through atmospheric transport.     

Hydroxylated and methoxylated polybrominated diphenyl ethers in a Canadian Arctic marine food web

Residues of hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have been previously detected in precipitation, surface waters, wildlife, and humans. We report measured concentrations of OH-PBDEs, MeO-PBDEs, and Br3-Br7 PBDEs in sediments and biota from a Canadian Arctic marine food web. PBDEs exhibited very low trophic magnification factors (TMFs between 0.1-1.6), compared to recalcitrant PCBs (TMFs between 3 and 11), indicating biotransformation via debromination and/or cytochrome P450 mediated metabolism. OH-PBDEs were not detectable in samples of blood, muscle, and/or liver of fish and marine wildlife. Five OH-PBDEs were detected at very low concentrations (range: 0.01-0.1 ng x g(-1) lipid equivalent) in beluga whale blubber and milk. The data indicate negligible formation/retention of OH-PBDEs in these Arctic marine organisms. Appreciable levels of several MeO-PBDEs were observed in bivalves, Arctic cod, sculpin, seaducks, and beluga whales (mean range 0.1-130 ng x g(-1) lipid equivalent). 2'-MeO-BDE-68 and 6-MeO-BDE-47 exhibited the highest concentrations among the brominated compounds studied (including BDE-47 and BDE-99) and biomagnified slightly in the food web, with TMFs of 2.3 and 2.6, respectively. OH- and MeO-PBDEs in this Arctic marine food web may occur via metabolic transformation of PBDEs or bioaccumulation of PBDE degradation products and/or natural marine products. We observed no evidence of a local natural source of OH- or MeO-PBDEs, as no measurable quantities of those compounds were observed in ambient environmental media (i.e., sediments) or macroalgae. Further investigations of PBDEs and their hydroxylated and methoxylated analogues would be useful to better understand sources, fate, and mechanisms governing biotransformation and bioaccumulation behavior of these compounds.     

Brominated flame retardants, polychlorinated biphenyls, and organochlorine pesticides in captive giant panda (ailuropoda melanoleuca) and red panda (Ailurus fulgens) from China

Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BFRs) were investigated in captive giant and red panda tissues from China. The total concentrations of OCPs, PCBs, and polybrominated diphenyl ethers (PBDEs) in tissues ranged from 16.3 to 888 ng/g lipid weight (lw), 24.8 to 854 ng/g lw, and 16.4 to 2158 ng/g lw, respectively. p,p'-DDE and beta-HCH were major OCP contaminants. PCBs 99, 118, 153/132, 170, 180, and 209 were the major contributing congeners determined. Among PBDEs, congener BDE-209 was the most frequent and abundant, followed by BDE-206, BDE-208, BDE-207, BDE-203, BDE-47, and BDE-153. Decabromodiphenyl ethane (DeBDethane) was detected in 87 and 71% of the giant and red panda samples with concentrations up to 863 ng/g lw, respectively. The remarkable levels and dominance of BDE-209 and DeBDethane may relate to significant production, usage, or disposal of BFRs in China. The positive significant correlation between concentrations of PBDEs and PCBs in captive pandas may suggest that the exposure routes of PBDEs and PCBs to panda are similar. To our knowledge, this is the first report of the occurrence of DeBDethane in captive wildlife samples. Therefore, further studies are warranted to better understand DeBDethane production, transport, uptake, and toxicological effect.     

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.     

Persistent organic pollutants in two dolphin species with focus on toxaphene and polybrominated diphenyl ethers

Assessing trends of persistent organic pollutants (POPs) in marine mammals is difficult due to age, gender, and metabolism influences on accumulation. To help elucidate these effects in dolphins, POP concentrations were determined in the Atlantic white-sided dolphin, Lagenorhynchus acutus, a pelagic delphinid inhabiting North Atlantic waters, and in the rough-toothed dolphin, Steno bredanensis, a pelagic delphinid inhabiting tropical and subtropical waters. The specific objectives of this study were to determine baseline POP concentrations in L. acutus and S. bredanensis blubber samples and to examine the effects of age, gender, and metabolism on POP concentrations in dolphin blubber. Focus was aimed at contaminants of emerging concern, specifically, toxaphene and polybrominated diphenyl ethers (PBDEs). Samples collected from L. acutus (n = 47) stranding events in Massachusetts (1993--2000) and S. bredanensis samples (n = 15) were analyzed for PCBs, toxaphene, and other organic pesticides by gas chromatography/mass spectrometry (GC/MS). Age and gender influences were similar between the two species, with adult females having significantly lower POP concentrations as compared to adult males and juveniles. Mean sigma toxaphene concentrations were highest in juvenile L. acutus, 13.0 (6.7) microg/g wet mass (1 SD), and lowest in adult female S. bredanensis, 1.49 (1.4) microg/g wet mass. sigma PBDE (sum of congeners 47, 99, 100, 153, and 154) concentrations were highest in juvenile L. acutus, 2.41 (1.2) microg/g wet mass, and lowest in adult female S. bredanensis, 0.51 (0.6) microg/g wet mass. POP concentrations did not significantly differ between adult males and juveniles, suggesting metabolism of congeners and/or dilution with growth. PBDE concentrations in juvenile white-sided dolphins were not significantly related to collection year, suggesting that there may be a lag period for higher concentrations to be detected in pelagic marine mammals such as L. acutus or that concentrations have already peaked in this species prior to the first collection in 1993.     

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and polychlorinated biphenyls in human tissues, meat, fish, and wildlife samples from India

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and non- and mono-ortho-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in tissues of humans, fishes, chicken, lamb, goat, predatory birds, and Ganges River dolphins collected from various locations in India. PCDDs/DFs were found in most of the samples analyzed with the liver of spotted owlet containing the highest concentration of 3,300 pg/g, fat wt. 2,3,7,8-Substituted PCDDs and PCDFs were found in human fattissues at concentrations ranging from 170 to 1,300 pg/g, fat wt. Concentrations of PCDDs were generally greaterthan those of PCDFs in human tissues, fishes, animal fat, and dolphin. Among fishes, meat, and wildlife samples analyzed, concentrations of PCDDs/DFs were found in the following order: country chicken < goat/lamb fat < fishes < river dolphins < predatory birds. Hepta-CDDs and OCDD were the major PCDD homologues found in humans, fishes, meat products, and dolphins. 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents of PCDDs/DFs were greater than those of PCBs in selected fish, dolphin, and human samples. To our knowledge, this is the first report of PCDDs and PCDFs in human tissues, fishes, meat, and wildlife collected from India.     

Perfluorooctanesulfonate and related fluorinated hydrocarbons in marine mammals,fishes, and birds from coasts of the Baltic and the Mediterranean Seas

Perfluorooctanesulfonate (PFOS; C8F17SO3-), perfluorooctanesulfonamide (FOSA; C8F17SO2NH2), perfluorohexanesulfonate (PFHxS; C6F13SO3-), and perfluorooctanoate (PFOA; C7F15CO2-) were detected in 175 samples of liver and blood of bluefin tuna (Thunnus thynnus), swordfish (Xiphias gladius), common cormorants (Phalacrocorax carbo), bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), common dolphins (Delphinus delphi), fin whales (Balenoptera physalus), and long-finned pilot whales (Globicephala melas) from the Italian coast of the Mediterranean Sea and in livers of ringed seals (Phoca hispida), gray seals (Halichoerus grypus), white-tailed sea eagles (Haliaeetus albicilla), and Atlantic salmon (Salmo salar) from coastal areas of the Baltic Sea. PFOS was detected in all of the wildlife species analyzed. Concentrations of PFOS in blood decreased in order of bottlenose dolphins > bluefin tuna > swordfish. Mean PFOS concentrations (61 ng/ g, wet wt) in cormorant livers collected from Sardinia Island in the Mediterranean Sea were less than the concentrations of PFOA (95 ng/g, wetwt). PFOS concentrations in cormorant livers were significantly correlated with those of PFOA. FOSA was found in 14 of 19 livers or blood samples of marine mammals from the Mediterranean Sea. The highest concentration of 878 ng FOSA/g, wet wt, was found in the liver of a common dolphin. Livers of ringed and gray seals from the Bothnian Bay in the Baltic Sea contained PFOS concentrations ranging from 130 to 1,100 ng/g, wet wt. No relationships between PFOS concentrations and ages of ringed or gray seals were observed. Concentrations of PFOS in livers of seals were 5.5-fold greater than those in corresponding blood. A significant positive correlation existed between the PFOS concentrations in liver and blood, which indicates that blood can be used for nonlethal monitoring of PFOS. Trend analysis of PFOS concentrations in livers of white-tailed sea eagles collected from eastern Germany and Poland since 1979 indicated an increase in concentrations during the 1990s. Livers of Atlantic salmons did not contain quantifiable concentrations of any of the fluorochemicals monitored. PFOS is a widespread contaminant in wildlife from the Baltic and the Mediterranean Seas, while FOSA and PFOA were detected only in certain locations indicating their sporadic spatial distribution.     

Serum concentrations of neutral and phenolic organohalogens in pregnant women and some of their infants in The Netherlands

As part of a large European Union (EU)-funded comparative toxicology and human epidemiology study, EU-Compare, a selection of organohalogen compounds (OHCs) was analyzed in maternal serum, collected at the 35th week of pregnancy, and in cord serum of a number of their infants to determine maternal concentrations and to investigate the extent of transplacental transfer of these compounds. Eight neutral OHCs were analyzed: one polychlorinated biphenyl (PCB: CB-153),4,4'-DDE, five polybrominated diphenyl ethers (PBDEs: BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154), and hexabromocyclododecane (HBCDD). Five phenolic OHCs were analyzed: three hydroxylated PCBs (40H-CB-107, 40H-CB-146, and 40H-CB-187), one hydroxylated PBDE (60H-BDE-47), and pentachlorophenol (PCP). All OHCs, except 60H-BDE-47, were present in maternal and cord serum. The historically identified OHCs showed the highest concentration: 4,4'-DDE (median value 89 ng/g lipid in maternal serum and 68 ng/g lipid in cord serum) and PCP (median value 970 pg/g serum in maternal serum and 1500 pg/g serum in cord serum). HBCDD and the PBDEs were present at much lower concentrations. We conclude that OHCs are present in the serum of pregnant women, and all compounds tested are transferred over the placenta. Because transfer is occurring at a critical stage of infant development, investigation of the health impact is urgent.     

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.     

Distribution of polybrominated diphenyl ethers in sediments of the Pearl River Delta and adjacent South China Sea

Spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs) in sediments of the Pearl River Delta (PRD) and adjacent South China Sea (SCS) of southern China were examined. A total of 66 surface sediment samples were collected and analyzed to determine the concentrations of 10 PBDE congeners (BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209). The concentrations of BDE-209 and SigmaPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) ranged from 0.4 to 7340 and from 0.04 to 94.7 ng/g, respectively. The SigmaPBDEs concentrations were mostly < 50 ng/g, within the range for riverine and coastal sediments around the world, whereas the BDE-209 concentrations at the most contaminated sites were at the high end of the worldwide figures. Congener compositions were dominated by BDE-209 (72.6 - 99.7%), with minor contributions from penta- and octa-BDEs. Slightly different PBDE compositions were observed among samples collected from different locations, attributable to possible decomposition of highly brominated congeners and/or redistribution between particles of various sizes during atmospheric or fluvial transportation. The PBDE patterns in the SCS and Pearl River Estuary sediments were similar to those in sediments of the Zhujiang and Dongjiang Rivers, reflecting the widespread influence from local inputs. Analyses of two short sediment cores collected from the Pearl River Estuary showed that concentrations of BDE-209 rapidly increased in the upper layers of both cores, coincident with the growth of the electronics manufacturing capacities in the PRD region. The major sources of PBDEs were probably waste discharges from the cities of Guangzhou, Dongguan, and Shenzhen, the three fastest growing urban centers in the PRD.     

Levels and distribution of polybrominated diphenyl ethers in water, surface sediments, and bivalves from the San Francisco Estuary

Polybrominated diphenyl ethers (PBDEs) were found in water, surface sediments, and bivalve samples that were collected from the San Francisco Estuary in 2002. sigmaPBDE concentrations in water samples ranged from 3 to 513 pg/ L, with the highest concentrations found in the Lower South Bay (range 103-513 pg/L) region, which receives approximately 26% of the Estuary's wastewater treatment plant effluents. The sigmaPBDEs in sediments ranged from below detection limits to 212 ng/g dry wt, with the highest concentration found at a South Bay station (212 ng/g dry wt), which was up to 3 orders of magnitude higher than other stations. The sigmaPBDE concentrations ranged from 9 to 64 ng/g dry wt in oysters (Crassostrea gigas), from 13 to 47 ng/g dry wt in mussels (Mytilus californianus), and from 85 to 106 ng/g dry wt in clams (Corbicula fluminea). Only three PBDE congeners were detected in bivalves, BDE-47, BDE-99, and BOE-100; these are the most bioaccumulative congeners from the commercial Penta-BDE mixture.     

Fine-scale spatial variation of persistent organic pollutants in bottlenose dolphins (Tursiops truncatus) in Biscayne Bay, Florida

Bottlenose dolphins (Tursiops truncatus) are long-term residents and apex predators in southeast U.S. estuaries and are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Dart biopsy samples were collected from 45 dolphins in Biscayne Bay (Miami, FL), 34 of which were matched using fin markings to a photo identification catalogue. Blubber samples were analyzed for 73 polychlorinated biphenyl (PCB) congeners, six polybrominated diphenyl ether (PBDE) congeners, and organochlorine pesticides including dichloro-diphenyl-trichloroethane (DDT) and metabolites, chlordanes, and dieldrin. Total PCBs (sigma 73PCBs) were present in the highest concentrations and were 5 times higher in males with sighting histories in the northern, metropolitan area of Biscayne Bay than males with sighting histories in the southern, more rural area [geometric mean: 43.3 (95% confidence interval: 28.0-66.9) vs 8.6 (6.3-11.9) microg/g wet mass, respectively]. All compound classes had higher concentrations in northern animals than southern. The differences in POP concentrations found on this small geographic scale demonstrate that differential habitat use can strongly influence pollutant concentrations and should be considered when interpreting bottlenose dolphin POP data. The PCB concentrations in northern Bay dolphins are high as compared to other studies of estuarine dolphins and may place these animals at risk of reproductive failure and decreased immune function.