Transfer Of Polybrominated Diphenyl Ethers Research Articles

Persistent autism-relevant behavioral phenotype and social neuropeptide alterations in female mice offspring induced by maternal transfer of PBDE congeners in the commercial mixture DE-71

Polybrominated diphenyl ethers (PBDEs) are ubiquitous persistent organic pollutants (POPs) that are known neuroendocrine disrupting chemicals with adverse neurodevelopmental effects. PBDEs may act as risk factors for autism spectrum disorders (ASD), characterized by abnormal psychosocial functioning, although direct evidence is currently lacking. Using a translational exposure model, we tested the hypothesis that maternal transfer of a commercial mixture of PBDEs, DE-71, produces ASD-relevant behavioral and neurochemical deficits in female offspring. C57Bl6/N mouse dams (F0) were exposed to DE-71 via oral administration of 0 (VEH/CON), 0.1 (L-DE-71) or 0.4 (H-DE-71) mg/kg bw/d from 3 wk prior to gestation through end of lactation. Mass spectrometry analysis indicated in utero and lactational transfer of PBDEs (in ppb) to F1 female offspring brain tissue at postnatal day (PND) 15 which was reduced by PND 110. Neurobehavioral testing of social novelty preference (SNP) and social recognition memory (SRM) revealed that adult L-DE-71 F1 offspring display deficient short- and long-term SRM, in the absence of reduced sociability, and increased repetitive behavior. These effects were concomitant with reduced olfactory discrimination of social odors. Additionally, L-DE-71 exposure also altered short-term novel object recognition memory but not anxiety or depressive-like behavior. Moreover, F1 L-DE-71 displayed downregulated mRNA transcripts for oxytocin (Oxt) in the bed nucleus of the stria terminalis (BNST) and supraoptic nucleus, and vasopressin (Avp) in the BNST and upregulated Avp1ar in BNST, and Oxtr in the paraventricular nucleus. Our work demonstrates that developmental PBDE exposure produces ASD-relevant neurochemical, olfactory processing and behavioral phenotypes that may result from early neurodevelopmental reprogramming within central social and memory networks.

Trophic transfer of polybrominated diphenyl ethers in a recently modified freshwater food web from the St. Lawrence River, Canada

Introduction of invasive species can have a profound impact on food web structure and therefore on trophic transfer of contaminants. In the St. Lawrence River (Canada), 20 years after its first detection in the system, invasive round goby (Neogobius melanostomus) has become the main prey for several piscivorous species. To evaluate the accumulation, trophic transfer, and the ecological risk of polybrominated diphenyl ethers (PBDEs) in this recently modified freshwater food web, samples of sediment, invertebrates, fish and aquatic bird eggs and plasma were collected. Sampling sites were located upstream and at two locations downstream of the Montreal wastewater treatment plant outfall. The results suggest that the influence of the WWTP effluent on PBDEs concentrations varied among the various compartments of this recently modified freshwater food web. The results also suggest that although predatory fish have switched to consuming round goby as a prey item instead of native yellow perch, this new feeding behaviour is not expected to have important impacts on the level of transfer of PBDE within this food web. The biota-sediment accumulation factors (BSAFs) ranged from 0.6 to 436, whereas biomagnification factors (BMFs) varied between 0.2 and 475. Despite our conservative method of risk assessment, we calculated an important risk for piscivorous fish and gull eggs within this study area.

Tissue-specific distribution and maternal transfer of polybrominated diphenyl ethers (PBDEs) and their metabolites in adult common sole (Solea solea L.) over an entire reproduction cycle

Tissue-specific accumulation and distribution of polybrominated diphenyl ethers (PBDEs) and their debrominated metabolites were studied in common sole (Solea solea) over an entire reproduction cycle. The fish were dietary-exposed to selected PBDEs in laboratory-controlled conditions for one year. Fish of both sexes were sampled throughout the reproduction cycle and their muscle, liver, viscera, carcass, skin and gonads (female) were analysed for total lipid content, PBDEs and their debrominated metabolites.On a wet weight basis, the concentrations of most spiked congeners showed an increase at the end of the exposure time in the whole body of fish of both sexes. Conversely, BDE-99 and BDE-209 – the two most highly metabolized congeners – did not show a similar increase, while their debrominated metabolites exhibited a linear increase over time.Biomagnification factors (BMFs) calculated in whole body were > 1 for all PBDEs except BDE-99 (0.89 ± 0.22) and BDE-209 (0.013 ± 0.006). BMFs were strongly correlated to apparent assimilation efficiencies, which ranged from 1.6% ± 0.7% (BDE-209) to 88% ± 11% (BDE-100).Fish carcass was the most predominant storage compartment for all PBDEs except BDE-209 in both male and female fish, followed by skin, muscle, female gonads, liver and visceral tissue. BDE-209 showed a different distribution and was stored more predominantly in the liver, viscera and female gonads than other congeners, probably due to its transport with lipoproteins. All PBDEs except BDE-209 showed equilibrium partitioning between the liver and other studied compartments, while BDE-209 showed a higher affinity with blood-enriched tissues, leading to higher liver / carcass, skin and muscle concentration ratios. Visceral tissue and liver exhibited the most pronounced differences in terms of concentration variations between sexes and over time. In females, both tissues showed a significant decrease in most PBDE concentrations (ww) and TLC in March during the spawning season, with low inter-individual variability, reflecting the striking utilisation of lipids by females for reproduction at this time. In males, no differences were found in concentrations in these compartments over time and a high inter-individual variability was observed.Maternal transfer of PBDEs from gonad to eggs was constant, regardless of spawn rank in the spawning season. Egg / gonad PBDE concentration ratios (in lw) were 1.3 ± 0.7 for all congeners and 2.6 ± 0.3 for BDE-209, suggesting a higher transfer of this congener from gonads to eggs.

Trophic magnification of polybrominated diphenyl ethers in the marine food web from coastal area of Bohai Bay, North China

Trophic transfer of polybrominated diphenyl ethers (PBDEs) in aquatic ecosystems is an important criterion for assessing their environmental risk. This study analyzed 13 PBDEs in marine organisms collected from coastal area of Bohai Bay, China. The concentrations of total PBDEs (Σ13PBDEs) ranged from 12 ± 1.1 ng/g wet weight (ww) to 230 ± 54 ng/g ww depending on species. BDE-47 was the predominant compound, with a mean abundance of 20.21 ± 12.97% of total PBDEs. Stable isotopic ratios of carbon (δ13C) and nitrogen (δ15N) were analyzed to determine the food web structure and trophic level respectively. Trophic magnification factors (TMFs) of PBDEs were assessed as the slope of lipid equivalent concentrations regressed against trophic levels. Significant positive relationships were found for Σ13PBDEs and eight PBDE congeners (BDE-28, BDE-47, BDE-49, BDE-66, BDE-85, BDE-99, BDE-100 and BDE-154). Monte-Carlo simulations showed that the probabilities of TMF >1 were 100% for Σ13PBDEs, BDE-47, BDE-85, BDE-99 and BDE-100, 99% for DE-28, BDE-49, BDE-66 and BDE-154, 94% for BDE-153, and 35% for BDE-17.

Polybrominated Diphenyl Ethers in Soils, Sediments, and Human Hair in a Plastic Waste Recycling Area: A Neglected Heavily Polluted Area

The release of pollutants during the recycling of contaminated plastics is a problem which has drawn worldwide attention; however, little information on the transfer of polybrominated diphenyl ethers (PBDEs) in these processes is available. We conducted a survey of PBDEs in soils, sediments, and human hair in a typical plastic waste recycling area in northern China. The total concentrations (ng/g) of 21 PBDEs were 1.25-5504 (average 600), 18.2-9889 (average 1619), and 1.50-861 (average 112) in soils, sediments, and hair, respectively. The PBDE concentrations were comparable to concentrations observed in e-waste recycling areas; however, the concentrations in soils and sediments were 1-3 orders of magnitude higher than in other areas, and the concentrations in hair were much higher than in other areas. This indicates that this area is highly polluted with PBDEs. BDE-209 was the dominant congener (representing 91.23%, 92.3%, and 91.5% of the total PBDEs observed in soils, sediments, and hair, respectively), indicating that the commercial deca-BDE product was dominant. The commercial penta- and octa-BDE products made small contributions to the total PBDE concentrations, unlike what has been found in some e-waste recycling areas. Our results show that crude plastic waste processing is a major contributor of PBDEs to the environment and humans, which should be of great concern.

Gridded Field Observations of Polybrominated Diphenyl Ethers in Soils of North China

Polybrominated diphenyl ethers (PBDEs) were measured in 87 soil samples collected from North China. Eleven PBDE congeners (BDE28, 47, 49, 66, 99, 100, 119, 183, 196, 203, and 209) were identified with a high frequency of detection (84-100 %) in soil samples, and their frequencies were used for statistical analysis in the present study. PBDE concentrations ranged from 0.08 to 8260 ng/g with a mean of 202 ng/g, thus indicating severe pollution at these sample sites. BDE209 was the predominant congener with concentrations of 0.08-8140 ng/g (mean 188). Analysis of the spatial distribution of PBDEs in North China soils indicated that relatively high concentrations of both lower- and higher-brominated BDEs were present in Shandong Province, and a decreasing trend in PBDE concentrations from the east toward the west of North China was observed. Source identification analysis suggested that Jinghai County in Tianjin and the coastal area of Laizhou Bay, Shandong province, were the major sources in North China. The sources in Jinghai County were connected with the dismantling of electronic waste, whereas the sources in the coastal area of Laizhou Bay were connected with the production of PBDEs. Modeling results showed that the distance between the sampling sites and these point sources had a large influence on the transfer of PBDEs.

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in a marine food web from Liaodong Bay, North China

The concentrations of 21 polybrominated diphenyl ethers (PBDEs) congeners were analyzed in organisms within a marine food web collected from the Liaodong Bay, North China. The total concentrations of PBDEs in all samples ranged from 0.87 to 91.4ngg−1 lipid weight (lw). BDE-47 was the predominant congener and had a concentration ranging from 0.30 to 36.1ngg−1lw. The trophic magnification factors (TMF) of the PBDEs were calculated using the trophic levels obtained from the stable nitrogen isotope ratios. The TMF value of ∑PBDEs was 3.50 for the entire food web and 2.21 for the food web excluding seabirds. Four concentration ratios, BDE-99/BDE-100, BDE-99/BDE-47, BDE-153/BDE-154 and BDE-183/BDE-154, decreased linearly with the increase of the trophic levels in the invertebrates and the fishes (p<0.01). The results suggested that the PBDEs were steadily metabolized in the trophic transfer process along the food chain.

Trophic transfer of polybrominated diphenyl ethers and polychlorinated biphenyls in a tidal freshwater marsh

The John Heinz National Wildlife Refuge (NWR) at Tinicum Marsh contains one of the last remaining tidal freshwater marsh communities along the Pennsylvania side of the Delaware River Estuary. The marsh receives a significant load of nutrients and sediment-associated contaminants and is hypothesised to act as an effective trap for these chemicals. The goal of this study was to quantify the levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) at various trophic levels at two sites within Tinicum Marsh and assess the factors important in determining their bioaccumulation and trophic transfer. For both PCBs and PBDEs, lipid variation for all species was a large factor in determining contaminant body burden. Also, concentrations in biota increased with increasing trophic level as determined by nitrogen isotope analysis (δ15N values) at the downstream site within Tinicum Marsh. This trend was less apparent at the upstream site and may be due to differences in feeding behaviours among species between the two sites and/or differences in carbon and nitrogen sources and recycling. These data are valuable in assisting bioaccumulation/trophic transfer studies and serve as benchmarks to which future PCB and PBDE concentrations will be compared.

Polybrominated diphenyl ethers in maternal serum, umbilical cord serum, colostrum and mature breast milk. Insights from a pilot study and the literature

Human serum and mother's milk are frequently used to assess exposure to polybrominated diphenyl ethers (PBDEs), including transplacental transfer to the foetus. However, little is known about the kinetics of PBDEs, especially the highly brominated BDE congeners.In this pilot study, maternal serum samples were collected from 10 women at delivery and five to six weeks post partum. Umbilical serum was also obtained. Milk was donated two to five days, and five to six weeks after delivery. The amount of PBDEs in these samples was determined using liquid–liquid extraction and GC/MS.Low, moderately and highly brominated diphenyl ethers were present in umbilical cord serum, indicating placental transfer. The lipid-adjusted levels of BDE-47, BDE-207 and BDE-209 were similar in maternal and umbilical cord serum, whereas the cord serum levels for the penta- to octa-BDEs quantified were lower than in maternal serum.Marked changes were seen in the congener pattern in breast milk during the first month of lactation, whereas maternal serum levels did not change significantly. The general pattern was an enrichment of low to moderately brominated congeners (i.e. from BDE-17 to BDE-154, with the exception of BDE-28) in colostrum compared with maternal serum. In contrast, more highly brominated congeners were found at similar, or lower levels in colostrum than in maternal serum. After the transition from colostrum to mature milk, the levels of BDE-153 and BDE-209 were substantially reduced, and BDE‐209 was below the limit of detection in 6 out of 9 samples.A literature review on the design and reporting of studies on the transfer of PBDEs from mother to infant revealed a lack of transparency in many cases. The use of the recently published STROBE-ME guidelines is therefore recommended.

Parental Transfer of Polybrominated Diphenyl Ethers (PBDEs) and Thyroid Endocrine Disruption in Zebrafish

Polybrominated diphenyl ethers (PBDEs) have the potential to disrupt the thyroid endocrine system. The objective of the present study was to characterize the disrupting effects of long-term exposure on the thyroid endocrine system in adult fish and their progeny following parental exposure to PBDEs. Zebrafish (Danio rerio) embryos were exposed to environmentally relevant concentrations (1, 3, and 10 μg/L) of the PBDE mixture DE-71 for 5 months until sexual maturation. In the F0 generation, exposure to DE-71 significantly increased plasma thyroxine (T4) but not 3,5,3'-triiodothyronine (T3) in females. This increased T4 was accompanied by decreased mRNA levels of corticotropin-releasing hormone (CRH) and thyrotropin β-subunit (TSHβ) in the brain. The F1 generation was further examined with or without continued DE-71 treatment conditions. Exposure to DE-71 in the F0 fish caused significant increases in T4 and T3 levels in the F1 larvae and modified gene expressions in the hypothalamic-pituitary-thyroid axis (HPT axis) under both conditions. Decreased hatching and inhibition of growth in the F1 offspring were observed in the condition without DE-71 treatment. Continued DE-71 treatment in the F1 embryos/larvae resulted in further decreased hatching, and increased malformation rates compared with those without DE-71 exposure. Analysis of F1 eggs indicated that parental exposure to DE-71 could result in a transfer of PBDEs and thyroid hormones (THs) to their offspring. For the first time, we demonstrated that parental exposure to low concentrations of PBDEs could affect THs in the offspring and the transgenerational PBDE-induced toxicity in subsequent nonexposed generations.

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in biota from the Pearl River Estuary, South China

Two hundred and fifty-four biota samples (four species of invertebrates and ten species of fish) were collected from the Pearl River Estuary between 2005 and 2007 and one hundred and twenty four individual or composite samples were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of PBDEs in organisms varied from 6.2 to 208 ng/g lipid weight. This PBDE level was significantly lower than those collected in 2004, showing a decreasing trend of PBDEs in biota in the study area. Trophic magnification factors (TMFs) for nine BDE congeners were calculated with values ranging from 0.78 to 3.0. TMFs of BDE47, 66, 100, 99, 154, and 153 were statistically greater than one, indicating a biomagnifcation potential for these congeners. Significant positive correlations were also found between concentrations of the total PBDEs, BDE28, 47, 66, 100, 99, 154, and153 and lipid content in biota, indicating the that bioconcentration also played an important role in the accumulation of PBDEs. No correlation between trophic level and lipid content was found, suggesting that biomagnification was not the result of lipid content effect but indeed occurred. The concentration ratios of BDE99 to BDE100 were much lower in biota than that in water implying that potential congener-specific biotransformation of PBDEs occurred and influenced the biomagnification of BDE congeners.

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.