Halogenated flame retardants in home-produced eggs from an electronic waste recycling region in South China: levels, composition profiles, and human dietary exposure assessment

Brominated flame retardant emissions from the open burning of five plastic wastes and implications for environmental exposure in China

Based on the most widely used plastics in China, five plastic wastes were selected for investigation of brominated flame retardant (BFR) emission behaviors during open burning. Considerable variations were observed in the emission factors (EF) of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) from the combustion of different plastic wastes. Distribution of BFR output mass showed that ΣPBDE was emitted mainly by the airborne particle (51%), followed by residual ash (44%) and the gas phase (5.1%); these values for ΣHBCD were 62%, 24%, and 14%, respectively. A lack of mass balance after the burning of the plastic wastes for some congeners (output/input mass ratios>1) suggested that formation and survival exceeded PBDE decomposition during the burns. However, that was not the case for HBCD. A comparison with literature data showed that the open burning of plastic waste is major source of PBDE compared to regulated combustion activities. Even for state-of-the-art waste incinerators equipped with sophisticated complex air pollution control technologies, BFRs are released on a small scale to the environment. According to our estimate, ΣPBDE release to the air and land from municipal solid waste (MSW) incineration plants in China in 2015 were 105 kg/year and 7124 kg/year. These data for ΣHBCD were 25.5 and 71.7 kg/year, respectively. Considering the fact that a growing number of cities in China are switching to incineration as the preferred method for MSW treatment, our estimate is especially important. This study provides the first data on the environmental exposure of BFRs emitted from MSW incineration in China.

Aquatic bioaccumulation and trophic transfer of tetrabromobisphenol-A flame retardant introduced from a typical e-waste recycling site

While the flame retardant chemical, tetrabromobisphenol-A (TBBP-A), has been frequently detected in the environment, knowledge regarding its species-specific bioaccumulation and trophic transfer is limited, especially in the highly contaminated sites. In this study, the components of an aquatic food web, including two invertebrates, two prey fish, and one predator fish, collected from a natural pond at an electronic waste (e-waste) recycling site in South China were analyzed for TBBP-A, using liquid chromatography-tandem mass spectrometry. The aquatic species had TBBP-A concentrations ranging from 350 to 1970 pg/g wet weight, with higher concentrations in the invertebrates relative to the fish species. Field-determined bioaccumulation factors of TBBP-A in the two aquatic invertebrates were nearly or greater than 5000, suggesting that TBBP-A is highly bioaccumulative in the two species. The lipid-normalized concentrations of TBBP-A in the aquatic species were negatively correlated with the trophic levels determined from stable nitrogen isotope (δ(15)N) (r = -0.82, p = 0.09), indicating that this compound experienced trophic dilution in the current food web.

Advances in in vitro methods to evaluate oral bioaccessibility of PAHs and PBDEs in environmental matrices

Cleanup goals for sites contaminated with persistent organic pollutants (POPs) are often established based on total contaminant concentrations. However, mounting evidence suggests that understanding contaminant bioavailability in soils is necessary for accurate assessment of contaminant exposure to humans via oral ingestion pathway. Animal-based in vivo tests have been used to assess contaminant bioavailability in soils; however, due to ethical issues and cost, it is desirable to use in vitro assays as alternatives. Various in vitro methods have been developed, which simulate human gastrointestinal (GI) tract using different digestion fluids. These methods can be used to predict POP bioavailability in soils, foods, and indoor dust after showing good correlation with in vivo animal data. Here, five common in vitro methods are evaluated and compared using PAHs and PBDEs as an example of traditional and emerging POPs. Their applications and limitations are discussed while focusing on method improvements and future challenges to predict POP bioavailability in different matrices. The discussions should shed light for future research to accurately assess human exposure to POPs via oral ingestion pathway.

Brominated flame retardants (BFRs): A review on environmental contamination in China

Brominated flame retardants (BFRs) which were detected extensively in environmental and biota samples worldwide, have raised significant concerns during past decades for their persistence, bioaccumulation and potential toxicity to ecological environment and human health. In this paper, we have compiled and reviewed existing literature on the contamination status of BFRs in abiotic and biotic environments in China, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane, tetrabromobisphenol A and new BFRs. Temporal trends were also summarized and evaluated. Based on this review, it has been concluded that (1) high concentrations of PBDEs were generally related to the e-waste disposal processing, while the spatial distribution pattern of other BFRs was not necessarily in accordance with this; (2) extremely high concentrations of BFRs in indoor dust emphasized the importance of indoor contamination to human body burdens, while more work need to be done to confirm its contribution; (3) PBDEs in electronics dismantling workers were higher compared to the general population, indicating the occupational exposure should be of particular concern; (4) more data are now becoming available for BFRs in aquatic and terrestrial organisms not previously studied, while studies that consider the occurrence of BFRs in organisms of different trophic levels are still of urgent need for evaluating the fate of BFRs in the food web; and (5) limited data showed a decreasing trend for PBDEs, while more data on time trends of BFR contamination in various matrices and locations are still needed before the impact of regulation of BFRs can be assessed.

Phosphate flame retardants and novel brominated flame retardants in home-produced eggs from an e-waste recycling region in China

Phosphate flame retardants (PFRs) and novel brominated flame retardants (NBFRs) (2-ethylhexyl-2,3,4,5-tetrabromo-benzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP)) were measured in free-range chicken eggs from three e-waste recycling sites and a negative control site located in Guangdong province, Southern China. BEH-TEBP, tris-(chloroethyl)-phosphate (TCEP), tris-(chloropropyl)-phosphate (∑TCPP, two isomers) and tris-(1,3-dichloroisopropyl)-phosphate (TDCIPP) were detected in more than 50% of eggs samples with low concentrations. The median values of BEH-TEBP and total PFRs were 0.17-0.46 ng/g ww (wet weight) and 1.62-2.59 ng/g ww in eggs from the e-waste sites, respectively. The results indicate that EH-TBB, BEH-TEBP and PFRs are less persistent and bioaccumulative than polybrominated diphenyl ethers (PBDEs) in chicken eggs, and possibly also in other bio-matrices. Triphenyl phosphate (TPHP) were identified in albumen with higher frequencies, but at similar concentrations compared to yolk, while BEH-TEBP was mainly detected in yolk. The estimated daily intake (EDI) of BEH-TEBP and total PFRs from consumption of chicken eggs ranged from 0.03 to 0.09 and 0.32-0.52 ng/kg bw/day for adults, and 0.20-0.54 and 1.89-3.02 ng/kg bw/day for children in e-waste sites, respectively. Indoor dust ingestion seems to be a more important pathway for the intake of these FRs, while egg consumption is probably a more important exposure pathway for PBDEs.

Maternal transfer of dechloranes and their distribution among tissues in contaminated ducks

The tissue concentrations of dechlorane plus and its analogues were determined in ducks collected from several e-waste recycling villages of Taizhou, China. Compared with the published literature, the relatively high concentrations of these compounds were detected in ducks, indicating serious DP contamination. Since both the duck meat and eggs were important components for diet, this result reminded us of keeping a watchful eye on human dietary exposure to DP and its analogues in this study area. The wet-weight concentrations of DP and its analogues were significantly related to tissue lipid content (p < 0.05), indicating that the lipid pools predominantly impacted the distribution of DPs in ducks. On the basis of lipid adjustment, the significantly lower levels in brain than those in liver and blood, displayed the occurrence of liver sequestration and blood-brain barrier to DP and its analogues in the duck (p < 0.05). The maternal transfer of DP and Mirex was not obviously limited, and the transferring extent of Dec 602 was over one. The stereo-selected accumulation of two DP isomers occurred among tissues with preference to syn-DP in blood, and to anti-DP in brain. The values of lipid-adjusted monodechlorinated products mainly originated from the exterior environment in ducks.

Dioxins, PCBs, chlorinated pesticides and brominated flame retardants in free-range chicken eggs from peri-urban areas in Arusha, Tanzania: Levels and implications for human health

The environment in the northern part of Tanzania is influenced by rapid population growth, and increased urbanization. Urban agriculture is common and of economic value for low income families. In Arusha, many households sell eggs from free-ranging backyard chicken. In 2011, 159 eggs from different households in five different locations in Arusha were collected, homogenized, pooled into 28 composite samples and analyzed for a wide selection of POPs. Levels of POPs varied widely within and between the locations. The levels of dieldrin and ΣDDT ranged between 2 and 98,791 and 2 and 324ng/g lipid weight (lw), respectively. EU MRLs of 0.02mg/kg dieldrin for eggs were exceeded in 4/28 samples. PCBs, HCHs, chlordanes, toxaphenes and endosulfanes were found at lower frequency and levels. Brominated flame retardants (BFRs), e.g polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD) and 1,2-bis(2,4,6-tribromphenoxy)ethane (BTBPE) were present in 100%, 60% and 46% of the composite samples, respectively. Octa-and deca-BDEs were the dominating PBDEs and BDE 209 levels ranged between <LOQ (limit of quantification) - 312ng/g lw. Dioxins were measured using the DR-LUC bio-assay and found in levels of <LOQ - 20pg bio-TEQs/g lw. Four samples (13%) exceeded the maximum level of 5pg/g total WHO-TEQs for hen eggs set by the Commission Regulation (EU) No 1259/2011. The daily/weekly intake was calculated and risk was characterized for all compounds comparing with available toxicity reference values (TRVs) such as the provisional tolerable intake (PTDI) or Reference Doses (RfDs). In one sample dieldrin exceeded the PTDI (100ng/kgbw/day). Correlation was found between bio-TEQs and lipid adjusted levels of ΣPBDEs, suggesting similar sources. Open fires in backyards may be one of the sources for contamination of eggs with BFRs and dioxins.

Environmental pollution of electronic waste recycling in India: A critical review

The rapid growth of the production of electrical and electronic products has meant an equally rapid growth in the amount of electronic waste (e-waste), much of which is illegally imported to India, for disposal presenting a serious environmental challenge. The environmental impact during e-waste recycling was investigated and metal as well as other pollutants [e.g. polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs)] were found in excessive levels in soil, water and other habitats. The most e-waste is dealt with as general or crudely often by open burning, acid baths, with recovery of only a few materials of value. As resulted of these process; dioxins, furans, and heavy metals are released and harmful to the surrounding environment, engaged workers, and also residents inhabiting near the sites. The informal e-waste sectors are growing rapidly in the developing countries over than in the developed countries because of cheapest labor cost and week legislations systems. It has been confirmed that contaminates are moving through the food chain via root plant translocation system, to the human body thereby threatening human health. We have suggested some possible solution toward in which plants and microbes combine to remediate highly contaminated sites.

Tissue Distribution and Transfer to Eggs of Ingested α-Hexabromocyclododecane (α-HBCDD) in Laying Hens (Gallus domesticus)

The aim of the current study was to describe the fate of ingested α-hexabromocyclododecane (α-HBCDD) in laying hens. Individuals were exposed to two dietary concentrations of α-HBCDD (50 and 5 ng g(-1) feed) for 18 or 11 weeks followed by a 7-week decontamination period. The results show that no isomerization of α- to β- or γ-HBCDD forms occurred, whereas OH-HBCDD was identified as a product of α-HBCDD metabolism. Irrespective of the level of feed contamination, estimates of steady-state accumulation ratios were 5.2, 3.6, and 9.2 and half-lives were estimated at 17.4, 22.8, and 35.3 days in egg yolk, liver tissue, and abdominal fat, respectively. The steady-state carry-over rate to eggs was 22.9%. Thus, α-HBCDD ingested by laying hens is readily transferred to eggs and significantly accumulates in adipose tissue.

Emerging halogenated flame retardants and hexabromocyclododecanes in food samples from an e-waste processing area in Vietnam

This study reports concentrations of selected emerging halogenated flame retardants (HFRs) and hexabromocyclododecanes (HBCDs) in foodstuffs sourced from an e-waste processing area in Vietnam and two reference sites in Vietnam and Japan. Concentrations of all target HFRs in e-waste-impacted samples in this study exceed significantly (p < 0.05) those detected in the controls, suggesting that e-waste processing activities exert a substantial impact on local environmental contamination and human dietary exposure. Significant linear positive correlations in concentrations of syn-Dechlorane Plus (DP) and anti-DP were found between soils and those in co-located chicken samples (p < 0.05). This implies that soil is an important exposure source of DPs in chickens at our sampling sites. The estimated dietary intakes of emerging HFRs in this study were 170 and 420 ng per kg bw per day for adults and children, respectively, while daily ingestions of HBCDs were estimated to be 480 and 1500 ng per kg bw per day for adults and children, respectively. Exposure at the site monitored in this study exceeds substantially the estimates of dietary exposure to HBCDs in e-waste processing sites and non-e-waste processing areas elsewhere.

Brominated flame retardants in food and environmental samples from a production area in China: concentrations and human exposure assessment

Human exposure to brominated flame retardants (BFRs: decabromodiphenyl ether (BDE209), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), 1,2,3,4,5-pentabromobenzene (PBBz), and 2,3,5,6-tetrabromo-p-xylene (TBX)) in a brominated flame retardant production area (Weifang, Shandong Province, China) was estimated. Thirty food samples, 14 air samples, and 13 indoor dust samples were analyzed. BDE209 and DBDPE were the dominant BFRs in all samples. Higher alternative brominated flame retardant (including DBDPE, HBB, PBEB, PBT, PBBz, and TBX) concentrations were found in vegetables than in fish and meat; thus, plant-original foods might be important alternative BFR sources in the study area. The BDE209 and alternative BFR concentrations in air were 1.5×10(4) to 2.2×10(5) and 620 to 3.6×10(4) pg/m3, respectively. Mean total BFR exposures through the diet, inhalation, and indoor dust ingestion were 570, 3000, and 69 ng/d, respectively (16, 82, and 2% of total intake, respectively). Inhalation was the dominant BFR source except for DBDPE, for which diet dominated. BDE209 contributed 85% of the total BFR intake in the study area.

Levels, spatial distribution, and exposure risks of decabromodiphenylethane in soils of North China

Eighty-seven soil samples collected from North China were analyzed for decabromodiphenyl ethane (DBDPE). The concentrations of DBDPE ranged from undetectable to 1612 ng/g, with the highest concentration present in Shandong. Additionally, the mean concentration of DBDPE in Shandong was found to be onefold higher than those found in Hebei and Shanxi, likely due to DBDPE production in Shandong. Relatively high concentrations of DBDPE in soils were also present in the south of Tianjin, where e-waste recycling may provide a source in this region. The fractions of DBDPE [DBDPE/(DBDPE + BDE209)] were lower than 0.5 in most soil samples, in agreement with the fact that deca-BDE is currently the main additive in brominated flame retardants (BFR) used in China. An obvious decreasing trend in DBDPE concentrations from east to west in North China was noted, with relatively higher DBDPE concentrations present in Shandong. A soil ingestion exposure assessment showed that for most sites, soil ingestion EDI was slightly lower than inhalation EDI; exceptions were found in several polluted sites, where soil ingestion was a more significant exposure route.

Bioaccumulative characteristics of tetrabromobisphenol A and hexabromocyclododecanes in multi-tissues of prey and predator fish from an e-waste site, South China

Tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) were analyzed in 12 tissues of prey (mud carp) and predator (northern snakehead) fish from an e-waste area, South China. The TBBPA concentrations in different tissues ranged from 0.03 to 2.85 ng/g wet weight (ww) in mud carp and 0.04 to 1.30 ng/g ww in northern snakehead. The concentrations of HBCDs ranged from 0.07 to 96.9 ng/g ww in mud carp and 0.18 to 240 ng/g ww in northern snakehead. HBCD levels in tissues were correlated with lipid content for both fish species, while this correlation was only found in mud carp for TBBPA. Meanwhile, northern snakehead exhibited higher HBCD levels but lower TBBPA levels than mud carps. These observations are attributed to the more polar and reactive properties of TBBPA than HBCDs. α-HBCD was the predominant diastereoisomer of HBCDs in all tissues of mud carp and northern snakehead, except for chyme of mud carp. All the analyzed tissues in mud carp showed an enrichment of (+)-α-HBCD enantiomer with EF (enantiomeric fraction) values of 0.53-0.62, but that in northern snakehead showed an enrichment of (-)-α-HBCD enantiomer with EF values of 0.35-0.5. Considering the fact that the mud carp is one of the diet items of northern snakehead, the different enantiomer accumulation characteristics of α-HBCD between the two fish species in the present study indicated that prey and predator fish could prefer to biotransform different enantiomers of α-HBCD.

Flame retardants and organochlorines in indoor dust from several e-waste recycling sites in South China: composition variations and implications for human exposure

Several classes of flame retardants, such as polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), dechlorane plus (DPs), and organophosphate flame retardants (PFRs), together with polychlorinated biphenyls (PCBs) were measured in indoor dust from five villages located in three e-waste recycling regions in Guangdong Province, South China. The medians of PBDEs, NBFRs, and PFRs in dust in five sites ranged from 685-67,500, 1460-50,010, and 2180-29,000ng/g, respectively. These concentrations were much higher than the medians of PCBs (52-2900ng/g). BDE 209 and decabromodiphenyl ethane (DBDPE) were the two major halogen flame retardants in dust, while tris-(1-chloro-2-propyl) phosphate (TCIPP) and triphenyl phosphate (TPHP) were the major PFRs. Principle component analysis revealed the different pollutant patterns among different sites. The estimated median human exposures of PBDEs, NBFRs, PFRs, and PCBs via dust ingestion were 1.1-24.1, 0.73-20.3, 1.36-23.5, and 0.04-0.93ng/kgbw/day for adults, and 16.2-352, 10.7-296, 19.9-343, 0.05-0.61, 0.65-13.6ng/kgbw/day for toddlers, respectively. Residents from Site 5 had the highest exposure (95 percentile levels and high dust ingestion for toddlers) of PBDEs (3920ng/kgbw/day), NBFRs (3200ng/kgbw/day), and PFRs (5280ng/kgbw/day). More attention should be paid to the contamination with NBFRs and PFRs, instead of PCBs, in these e-waste recycling regions, and local public health threat from PBDE alternatives should remain of concern. To the best of our knowledge, this is the first study on human exposure assessment of PFRs at e-waste sites.

Contaminant sources, gastrointestinal absorption, and tissue distribution of organohalogenated pollutants in chicken from an e-waste site

Several organohalogenated pollutants (OHPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) were examined in chicken dietary sources (soil and feed) and gastrointestinal contents (chyme, intestinal contents, and feces), and in 11 chicken tissues (liver, muscle, heart, lung, fat, brain, stomach, intestine, ovary/testis, kidney, and serum) from an e-waste recycling site in South China. Elevated levels of OHPs were found in the soil and chicken tissues. Soil was a more important source of OHPs, especially brominated flame retardants, than feed. In general, more-halogenated chemicals were less readily absorbed in the gastrointestinal tract. With the exception of the brain and serum, where lower concentrations occurred, no significant differences in PCBs, PBDEs, and BTBPE were found among the chicken tissues. DBDPE was detected mainly in the stomach, intestine, kidney, and ovary. Compared with the soil, all the tissues had lower proportions of CBs 52 and 101. PBDEs were dominated by BDE 209 in the soil and chicken feed; two different PBDE congener profiles, dominated by both BDE 183 and BDE 209 or dominated by BDE 209 only, were found in the chicken tissues except for the brain. Only BDE 47 or BDE 209 was occasionally detectable in the brain. DBDPE was also found in the brain samples despite its high log Kow values. The blood-brain barrier alters patterns of contaminant composition and results in lower levels of OHPs in the brain.

Human dietary intake of organohalogen contaminants at e-waste recycling sites in Eastern China

This study reports concentrations and human dietary intake of hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) as well as selected "novel" brominated flame retardants (NBFRs) and organochlorine pesticides, in ten staple food categories. Samples were sourced from areas in Taizhou City, eastern China, where rudimentary recycling and disposal of e-waste is commonplace, as well as from nearby non-e-waste impacted control areas. In most instances, concentrations in foods from e-waste recycling areas exceeded those from control locations. Concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TBP) in samples from e-waste sites were 3.09-62.2ng/g and 0.81-16.3ng/g lipid weight (lw), respectively; exceeding consistently those in foods acquired from control sites by an order of magnitude in many cases. In contrast, while concentrations of HBCD in some foods from e-waste impacted areas exceed those from control locations; concentrations in pork, shrimp, and duck liver are higher in control samples. This highlights the potential significance of non-e-waste sources of HBCD (e.g. building insulation foam) in our study areas. While concentrations of DDT in all foods examined except pork were higher in e-waste impacted samples than controls; our exposure estimates were well below the provisional tolerable daily intake of 0.01mg/kgbw/day derived by the Joint FAO/WHO Meeting on Pesticide Residues. Concentrations of ΣPCBs resulted in exposures (650 and 2340ng/kgbw/day for adults and children respectively) that exceed substantially the Minimal Risk Levels (MRLs) for ΣPCBs of 20ng/kgbw/day derived by the Agency for Toxic Substances & Disease Registry. Moreover, when expressed in terms of dioxin-like toxicity equivalency based on the four dioxin-like PCBs monitored in this study (DL-PCBs) (PCB-105, 118, 156, and 167); concentrations in e-waste impacted foods exceed limits set by the European Union in 6 of the 8 food groups studied and result in dietary exposures for children (10.2pgTEQ/kgbw/day) that exceed the WHO tolerable daily intake of 1-4pgTEQ/kgbw/day.

Hexabromocyclododecanes in surface sediments from Shanghai, China: spatial distribution, seasonal variation and diastereoisomer-specific profiles

The concentrations, spatial distribution, diastereoisomer-specific profiles of hexabromocyclododecanes (HBCDs) in surface sediments from three major rivers in Shanghai as well as the seasonal variation of HBCDs were investigated. The concentrations of total HBCD diastereoisomers ranged from 0.05 to 6.87ngg(-1)dw. Significant spatial distribution of total HBCDs concentrations were observed. The mean concentration of total HBCDs followed the order of Suzhou Creek (2.00ngg(-1))>Huangpu River (1.59ngg(-1))>Yunzao Creek (0.77ngg(-1)). The concentration was a relatively low HBCDs level compared to levels measured in domestic and other parts of the world. The proportions of α-HBCD in sediment samples were generally higher than that of commercial formulations. This might be due to thermal isomerization from γ-HBCD to α-HBCD and slower degradation rate of α-HBCD compared to γ-HBCD in anaerobic conditions. The concentrations of ΣHBCD in the summer were significantly higher than those in the winter (paired t test, p<0.01). This seasonal variation could probably be attributed to a combined effect of temperature and wet deposition. Moreover, a poor and no significant correlation between ΣHBCD levels and TOC content in sediments was observed, suggesting that the spatial distributions of HBCDs were not constrained by the TOC in sediments of Shanghai.

Halogenated flame retardants during egg formation and chicken embryo development: maternal transfer, possible biotransformation, and tissue distribution

Hen muscle, eggs, and newborn chick tissues (muscle and liver) were collected from an electronic waste recycling site in southern China. The authors examined the maternal transfer, potential metabolism, and tissue distribution of several halogenated flame retardants (HFRs) during egg formation and chicken embryo development. The pollutant composition changes significantly from hen muscle to eggs and from eggs to tissues of newborn chicks. Higher-halogenated chemicals, such as octa- to deca-polybrominated diphenyl ether (PBDE) congeners, deca-polybrominated biphenyl (PBB209), and dechlorane plus (DP), are less readily transferred to eggs compared with lower-halogenated chemicals. During embryo development, PBDEs are the most likely to be metabolized, whereas decabromodiphenyl ethane (DBDPE) is the least. The authors also observed selective maternal transfer of anti-DP and stereoselective metabolism of syn-DP during chicken embryo development. During tissue development, liver has greater affinity than the muscle for chemcials with a high log octanol-water partition coefficient, with the exception of DBDPE. The differences in metabolism potential of different chemicals in chicken embryos cause pollutant composition alterations. Halogenated flame retardant from maternal transfer and tissue distribution also exhibited chemical specificity, especially for DBDPE. Levels of DBDPE were elevated along with the full process from hen muscle to eggs and from eggs to chick tissues. More attention should be paid to the selective accumulation and biotransformation of HFRs in the early development stage of birds.

A systematic review of the human body burden of e-waste exposure in China

As China is one of the countries facing the most serious pollution and human exposure effects of e-waste in the world, much of the population there is exposed to potentially hazardous substances due to informal e-waste recycling processes. This report reviews recent studies on human exposure to e-waste in China, with particular focus on exposure routes (e.g. dietary intake, inhalation, and soil/dust ingestion) and human body burden markers (e.g. placenta, umbilical cord blood, breast milk, blood, hair, and urine) and assesses the evidence for the association between such e-waste exposure and the human body burden in China. The results suggest that residents in the e-waste exposure areas, located mainly in the three traditional e-waste recycling sites (Taizhou, Guiyu, and Qingyuan), are faced with a potential higher daily intake of these pollutants than residents in the control areas, especially via food ingestion. Moreover, pollutants (PBBs, PBDEs, PCBs, PCDD/Fs, and heavy metals) from the e-waste recycling processes were all detectable in the tissue samples at high levels, showing that they had entered residents' bodies through the environment and dietary exposure. Children and neonates are the groups most sensitive to the human body effects of e-waste exposure. We also recorded plausible outcomes associated with exposure to e-waste, including 7 types of human body burden. Although the data suggest that exposure to e-waste is harmful to health, better designed epidemiological investigations in vulnerable populations, especially neonates and children, are needed to confirm these associations.

Assessment of Dechlorane compounds in foodstuffs obtained from retail markets and estimates of dietary intake in Korean population

A total of 175 samples, composed of 35 different foodstuffs, were obtained from retail markets in Korea and analyzed to investigate the contamination status and dietary intake of Dechlorane compounds. The concentrations of Dechlorane Plus (DP), mirex, Dechlorane (Dec) 602 and 603 ranged from ND to 169.85 pg/g wet weight (ww), 107.30 pg/g ww, 20.81 pg/g ww, 0.41 pg/g ww, respectively, while Dechlorane (Dec) 604 was not detected in any samples. Strong correlations between anti- and syn-DP and between mirex and Dec 602 were observed. The average anti-isomer fractional abundance (fanti) was 0.78±0.11 which was larger than the technical DP value (fanti=0.75). The estimated dietary daily intake of DP, 11.2×10(3) pg/day, was one to three orders of magnitude higher than other Dechloranes. Grain was the most contributed food group to dietary daily intake of DP for Korean population.

Human dietary exposure to PBDEs around E-waste recycling sites in Eastern China

Analysis of 10 types of locally produced staple foods (including meat, fish, and eggs), provided estimates of dietary intakes of polybrominated diphenyl ethers (PBDEs) for residents of areas of Taizhou City (Zhejiang Province, Eastern China), which are long-established centers of rudimentary "e-waste" recycling. Average ∑PBDE concentrations in chicken meat, eggs, and liver and duck meat and liver were among the highest recorded to date, with BDE-209 particularly abundant. The highest estimated contributions to ∑PBDE intake under a median exposure scenario were associated with adult consumption of duck eggs (3882 ng/day) and chicken eggs (1091 ng/day), and with consumption of fish by both adults (792 ng/day) and children (634 ng/day). Including estimates for ingestion of contaminated dust reported elsewhere increased median ∑PBDE daily intakes by approximately 19% for adults and 42% for children. Normalized to body weight, estimated median ∑PBDE exposures (from food and dust combined) were 130.9 ng/kg bw/day for adults and 614.1 ng/kg bw/day for children. High-end estimates of exposure for young children exceeded the U.S. Environmental Protection Agency reference doses for BDE-47 and BDE-99 by factors of approximately 2.5 and 1.5, respectively.

Levels and trends of PBDEs and HBCDs in the global environment: status at the end of 2012

In this paper, we have compiled and reviewed the most recent literature, published in print or online from January 2010 to December 2012, relating to the human exposure, environmental distribution, behaviour, fate and concentration time trends of polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants, in order to establish their current trends and priorities for future study. More data are now becoming available for remote areas not previously studied, Indian Ocean islands, for example. Decreasing time trends for penta-mix PBDE congeners were seen for soils in northern Europe, sewage sludge in Sweden and the USA, carp from a US river, trout from three of the Great Lakes and in Arctic and UK marine mammals and many birds, but increasing time trends continue in polar bears and some birds at high trophic levels in northern Europe. This may be partially a result of the time delay inherent in long-range atmospheric transport processes. In general, concentrations of BDE209 (the major component of the deca-mix PBDE product) are continuing to increase. Of major concern is the possible/likely debromination of the large reservoir of BDE209 in soils and sediments worldwide, to yield lower brominated congeners which are both more mobile and more toxic, and we have compiled the most recent evidence for the occurrence of this degradation process. Numerous studies reported here reinforce the importance of this future concern. Time trends for HBCDs are mixed, with both increases and decreases evident in different matrices and locations and, notably, with increasing occurrence in birds of prey. Temporal trends for both PBDEs and HBCD in Asia are unclear currently. A knowledge gap has been noted in relation to metabolism and/or debromination of BDE209 and HBCD in birds. Further monitoring of human exposure and environmental contamination in areas of e-waste recycling, particularly in Asia and Africa, is warranted. More data on temporal trends of BDE and HBCD concentrations in a variety of matrices and locations are needed before the current status of these compounds can be fully assessed, and the impact of regulation and changing usage patterns among different flame retardants determined.

Domestic duck eggs: an important pathway of human exposure to PBDEs around e-waste and scrap metal processing areas in Eastern China

Although consumption of local foods is recognized as an important pathway of human exposure to PBDEs in areas of China involved in rudimentary recycling of electronic waste (e-waste), dietary intake studies to date have not considered the contribution from consumption of duck eggs, despite being a common dietary component. Fresh duck eggs (n = 11) were collected from each of five farms located within 500 m of e-waste recycling workshops in the Wenling and Luqiao districts of Taizhou City, Eastern China, in November 2011, along with eggs from a control site located 90 km to the northeast. Average ΣPBDE yolk concentrations in eggs from the Taizhou farms ranged from 52.7 to 1778 ng/g lipid weight (8 ng/g lipid weight at the control site), at the high end of values previously reported for PBDEs in chicken eggs from the same locations and with BDE-209 predominant in over 60% of samples. Estimated typical adult daily ΣPBDE intakes due to consumption of duck eggs were in the range of 159-5124 ng/person per day. For the pentabrominated BDE-99 congener, estimated intakes from duck eggs alone were substantially above the no adverse effect level (NAEL) for impaired human spermatogenesis proposed by Netherlands researchers.