Preliminary Study Of Polybrominated Diphenyl Ethers, Organochlorine Pesticides And Polychlorinated Biphenyls In Human Blood And Milk Of Special Populations From Guangdong Province

Polybrominated diphenyl ethers (PBDEs) are flame retardants, which are extensively used in plastics, electrical appliances, household and business furnishings. PBDEs are now ubiquitous environmental pollutants and may have toxic effects in humans and wildlife. The temporal studies have shown that PBDEs are increasing in humans in some regions of the world at an exponential rate in recent twenty years. The majority of studies on exposure to PBDEs are from Europe and America. However, no such reports have been conducted in China and there are few reports on the presence of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in human blood samples from China.This research is supported by National Natural Scientific Foundation of China (NO. 40590392: Geochemistry and Environmental Effect of POPs in Electronic Waste in Low Latitudinal Regions). This thesis aims to assess general exposure to PBDEs in human milk, maternal and fetal blood in Guangzhou and occupational exposure to PBDEs in workers at electronic waste dismantling region (Guiyu) and in residents nearby region (Haojiang). Highly brominated PBDE congeners (hepta- to deca) were analyzed in these samples as well as the low brominated PBDEs. Meanwhile, the concentrations of PCBs and OCPs were also measured. Examination of the concentrations and congener profiles in serum lipid of e-waste dismantlers may provide important information for the subsequent evaluation of health effects.The results showed that the concentrations of total PBDEs varied from 1.5 to 12 ng/g lw (median 3.9 ng/g lw), 1.6 to 17 ng/g lw (median 4.4 ng/g lw), and 1.7 to 7.2 ng/g lw (median 3.5 ng/g lw) in fetal serums, maternal serums, and breast milk, respectively. The level of PBDEs in maternal serum and human milk were within the range reported in Europe, and much lower than those of the United States. BDE-47 and BDE-153 were the dominant PBDE congeners in these samples. In addition, higher brominated PBDEs showed higher levels in maternal serum than in fetal serum. This result indicates that the higher brominated PBDEs have greater difficulty to pass through the placenta compared to the lower brominated congeners.The median concentration of IPBDEs from Guiyu showed 3 times higher than Haojiang. Hepta- to decaBDEs in occupational exposure workers were 11-20 times higher than in population from Guangzhou. The median concentration of BDE-209 in Guiyu was 50- to 200-fold higher than in previously reported occupationally exposed populations. The highest BDE-28, -183, -207 and BDE-209 concentrations were 148,60.2,66.2 and 3436 ng/g lw, the highest reported to date in humans worldwide. The results suggest that BDE-209 is still bioavailable. Highly brominated PBDE congeners significantly correlated with BDE-209 (p < 0.01) which implies that decaBDE exposure increased the human burden with the other highly brominated PBDEs.The median concentrationsΣHCHs were 12.2 and 34.2 ng/g lw in the workers and the residents, respectively.β-HCH was the dominant HCH isomer in this study. The major contributor (> 77%) to SDDTs was p,p'-DDE..The median concentrations ofΣDDTs were 602 and 1757 ng/g lw in the workers and the residents, respectively. The concentrations of HCB and chlordanes almost are similar in the workers and the residents. The concentrationΣOCPs detected in this study is much lower than in India but higher than the developed countries such as Japan and America. Linear regression analyses showed that there is a tendency for increasing concentration with age forΣDDTs, CHLs andΣHCHs in HaojiangThe median concentrations ofΣPCB were 90.7 and 66.5 ng/g lw in the workers and the residents, respectively. CB-138 and CB-153/132 were the dominant congeners in the two groups. The concentrations ofΣPCBs were much lower than in Europe and North America, which support the hypothesis of less usage of PCBs in China...