Eleven recently completed toxicological studies were critically reviewed to identify toxicologically significant endpoints and dose-response information. Dose-response data were compiled and entered into the USEPA's benchmark dose software (BMDS) for calculation of a benchmark dose (BMD) and a benchmark dose low (BMDL). After assessing 91 endpoints across the nine studies, a total of 23 of these endpoints were identified for BMD modeling, and BMDL estimates corresponding to various dose-response models were compiled for these separate endpoints. Thyroid, neurobehavior and reproductive endpoints for BDE-47, -99, -209 were quantitatively evaluated. According to methods and feature of each study, different uncertainty factor (UF) value was decided and subsequently reference doses (RfDs) were proposed. Consistent with USEPA, the lowest BMDLs of 2.10, 81.77, and 1698 I^g/kg were used to develop RfDs for BDE-47, -99, and -209, respectively. RfDs for BDE-99 and BDE-209 were comparable to EPA results, and however, RfD of BDE-47 was much lower than that of EPA, which may result from that reproductive/developmental proves to be more sensitive than neurobehavior for BDE-47 and the principal study uses very-low-dose exposure.
LI Lu XiCHEN LiCAO DanCHEN Bing HengZHAO YanMENG Xiang ZhouXIE Chang MingZHANG Yun Hui
Objective This paper is to assess the current status of polybrominated diphenyl ethers(PBDEs) contamination in the environment in China and estimate the exposure to PBDEs in non-occupational populations.Methods A total of 80 research papers published from January 2001 to October 2013 were selected.Geographic information system(GIS) was used in mapping PBDE concentrations and distributions in environmental media.Ni's model was applied to calculate ∑PBDE-intake via the intakes of contaminated food,water and air in the Pearl River Delta and Yangtze River Delta.Results BDE-209 was found to be the major PBDE congener in the environmental media and food in China.PBDE concentrations varied among different areas,among which the contamination in Guangdong Province was most serious.Daily intake of ∑PBDEs was 225.1-446.0 ng/d for adults in the Pearl River Delta,which was higher than the intake for those living in the Yangtze River Delta(148.9-369.8 ng/d).Conclusion PBDEs are ubiquitous in the environment of China.The estimated PBDEs daily dietary intake is comparable with that in European countries.
CHEN LiCAO DanLI Lu XiZHAO YanXIE Chang MingZHANG Yun Hui