Accumulation of polybrominated diphenyl ethers in breast milk of women from an e-waste recycling center in China

Polybrominated diphenyl ethers（PBDEs） can be transferred to infants through the ingestion of breast milk, resulting in potential health risk. In this study, PBDEs, hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and 2,2′,4,4′,5,6′-hexachlorobiphenyl（CB-153）in human milk from women living adjacent to e-waste recycling sites of Wenling,China, were investigated. The median level of PBDEs in samples from residents living in the e-waste recycling environment 〉 20 years（R20group, 19.5 ng/g lipid weight（lw））was significantly higher than that for residents living in Wenling 〈 3 years（R3group,3.88 ng/g lw）（p 〈 0.05）, likely ascribable to specific exposure to PBDEs from e-waste recycling activities. In the R20 group, most congeners（except for BDE-209） were correlated with each other（p 〈 0.05）. Moreover, CB-153 showed significant association with most PBDE congeners, rather than BDE-209. The relationship indicated that most BDE congeners other than BDE-209 shared common sources and/or pathways with CB-153, e.g., dietary ingestion. The correlations between BDE-209 and other congeners were different in the two groups, likely suggesting their different exposure sources and/or pathways for PBDEs.Although estimated dietary intake of PBDEs for infants via breast milk was lower than the minimum value affecting human health, the PBDE exposure of infants should be of great concern because of their potential effect on the development of neonates over long-term exposure. OH-PBDEs were not detected in the collected samples, which is in accordance with reports in published literature, likely indicating that they were not apt to be accumulated in human milk.

Bioavailability and tissue distribution of Dechloranes in wild frogs(Rana limnocharis) from an e-waste recycling area in Southeast China

Dechlorane Plus （DP）,a flame retardant used as an alternative to decabromodiphenylether, has been frequently detected in organisms, indicating its bioaccumulation and biomagnification potential in aquatic and terrestrial species. However, little data is available on the bioaccumulation of DP in amphibians. Dechlorane Plus and its analogs （DPs） were detected in the liver, muscle and brain tissues of wild frogs （Rana limnocharis）, which were collected from an e-waste recycling site, Southeast China. DP, Mirex, Dec 602 and a dechlorinated compound of DP （anti-Cll I-DP） varied in the range of 2.01-291, 0.650-179, 0.260-12.4, and not detected （nd）-8.67 ng/g lipid weight, respectively. No difference of tissue distribution was found for syn-DP, Mirex and Dec 602 between the liver and muscle tissue （liver/muscle concentration ratio close to 1, p 〉 0.05）. However, higher retention was observed for anti-DP and anti-Cll1-DP in the frog muscle relative to the liver tissue （liver/muscle concentration ratio 〈 1, p 〈 0.05）. Additionally, the blood-brain barrier was found to work efficiently to suppress these compounds entering brain tissues in this species （liver/brain concentration ratio 〉 l, p 〈 0.05）, and the molecular weight was a key factor impacting the extent of the blood-brain barrier. Compared to levels in the muscle and brain tissue, a preferential enrichment of syn-DP was observed in the liver tissue, suggesting the occurrence of stereo-selective bioaccumulation in the wild frog.