Halogenated POPs and PAHs in blood plasma of Hong Kong residents.

The objective of this study was to quantify organic chlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in blood plasma collected from 111 healthy residents in Hong Kong to assess the levels of these pollutants in the general population during the period of March to April, 2008. Concentrations of these residues in blood plasma obtained from the Hong Kong Red Cross Blood Transfusion Service were determined by gas chromatography-mass spectrometry. Naphthalene, phenanthrene, p,p'-DDE, PCB-180, and PBDE-47 were detected in 100% of the participants. Females had significantly greater concentrations of acenaphthylene (female: 93.3 ng/g lipid; male: 39.8, p < 0.05), anthracene (22.3; 15.3, p < 0.05), fluoranthene (138; 125, p < 0.05), p,p'-DDE, p,p'-DDT, PCB-183, BDE-99 than males. Blood of smokers contained significantly greater (p < 0.05) concentrations of acenaphthene, benzo(a)pyrene, p,p'-DDE, p,p'-DDT, PCB-138, BDE-47, and BDE-99 than did blood of nonsmokers. Positive correlations were found between concentrations of each class of pollutant, with respect to seafood diet habit, Body Mass Index (BMI), and age. Concentrations of HCHs and DDTs in blood plasma of healthy Hong Kong residents were greater than those of other countries, and it was found that smoking, consumption of a seafood diet, BMI, and age could influence concentrations in human blood.

Body burden of POPs of Hong Kong residents, based on human milk, maternal and cord serum.

This study is one of the very few investigating the body burdens of persistent organic pollutants in residents of Hong Kong. Twenty-nine human milk samples and 21 human blood (and cord blood) samples collected from 2005 were analyzed for PAHs, OCPs and PCBs levels. Higher levels of PAHs, DDTs and PCBs were detected in human milk samples when compared to maternal serum and cord serum (PAHs: milk: 1981 ng g⁻¹ fat, maternal serum: 1461, cord serum: 1158; DDTs: 3099, 1934, 1556; PCBs: 49, 41, 40). Among the 16 PAHs, naphthalene (human milk: 786 ng g⁻¹ fat, maternal serum: 331, cord serum: 348), phenanthrene (361, 144, 193), pyrene (187, 154, 98) and fluoranthene (158, 128, 89) were the major PAHs detected in three human tissues. p,p'-DDE and p,p'-DDT were the only metabolites of DDT detected in the three types of human tissues. High detection rate of the p,p'-DDE and p,p'-DDT (> 90%) were noted in the three types of human samples. On the contrary, low detection frequency of PCBs in human milk (10.7%), maternal serum (1.7%) and cord serum (0.8%) were observed. The correlation coefficients of the PAHs, DDTs and PCBs levels in the three types of human tissues together with fish consumption, maternal age and tissue fat were analyzed. The following significant correlations were observed: Σ DDTs and p,p'-DDE in human milk with consumption of freshwater and marine fish, and maternal age; Σ PCBs in human milk with marine fish consumption, and maternal age; Σ PAHs in human milk with maternal age, respectively. The estimated daily intakes of DDTs by infants indicated that 7 out of 29 of the human milk samples exceeded 20 ng g⁻¹ day⁻¹, the tolerable daily intake (TDI) proposed by the Health Canada Guideline in terms of DDTs levels. The high intake of DDTs by infants may be of concern as infants are more susceptible to the adverse effects imposed by various environmental contaminants. Human milk is a reliable and comparatively non-invasive tool for monitoring body loading of POPs, which also allows health risk assessment of residual chemicals on our next generation.

Body burdens of polybrominated diphenyl ethers in childbearing-aged women at an intensive electronic-waste recycling site in China.

BACKGROUND, AIM AND SCOPE: This study is the first to investigate PBDE body burden with regard to the concurrent analyses of multiple human matrices, namely milk, placenta, and hair, collected from a group of childbearing-aged women at an electronic waste (e-waste) recycling site to determine the partitioning of PBDEs in these different human matrices and the possible health risks imposed to infants at the e-waste recycling site. METHODS AND METHODS: Five sets of milk, placenta, and hair samples were collected from an e-waste site (Taizhou, Zhejiang Province) and a reference site (Lin'an city, Zhejiang Province; 245 km away from Taizhou) in China. The concentrations of total PBDEs in different human tissues were analyzed according to US EPA standard methods. RESULTS: PBDE body burdens of women from the e-waste site (milk 117 +/- 191, 8.89-457 ng/g fat, placenta 19.5 +/- 29.9, 1.28-72.1 ng/g fat, hair 110 +/- 210, 8.47-486 ng/g dry wt.) showed significantly higher levels than those from the reference site (milk 2.06 +/- 0.94, 1.0-3.56 ng/g fat, placenta 1.02 +/- 0.36, 0.59-1.42 ng/g fat, hair 3.57 +/- 2.03, 1.56-5.61 ng/g dry wt.) and were higher than those reported in other studies, due to e-waste recycling operations, especially open burning. On a dry-weight basis, the following trend was found for PBDE among the samples from Taizhou: hair>>milk>placenta. Among the donors, the body burden of an e-waste worker ranked second. Higher brominated BDEs (hepta-BDEs) contributed a significantly greater proportion to total PBDEs in hair of the Taizhou women (20%) than that in milk (2.9%) and in placenta (2.6%). The estimated intake of PBDEs of 6-month-old breastfed infants living at the e-waste site was 572 +/- 839 ng/kg body wt/day, which was 57 times higher than that of infants from the reference site (10.1 +/- 4.60 ng/kg body wt/day). Moreover, the maximum calculated value (2,240 ng/kg body wt/day) exceeded the chronic oral reference dose for penta-BDE (2,000 ng/kg/day) of US EPA. DISCUSSION: BDE-47 was the dominant congener accounting for 20-30% in all the individual samples, while higher-brominated congeners, for example, BDE-183 and BDE-190, contributed between 2% and 20%. The presence of hepta-BDE congeners (BDE-181, BDE-190) in hair of the women in Taizhou suggest that thermal degradation of Deca-BDE from the open burning of e-waste may have been their source because these congeners are not found in either Penta-BDE or Octa-BDE technical products. Of the three types of samples analyzed, it was also suspected that hair may be more favorable to higher-brominated compounds which might explain why the hair samples contained the highest total PBDE concentrations and the highest proportion of higher-brominated BDEs (hepta-BDEs). CONCLUSION: This study provides evidence that primitive e-waste recycling in China leads to high PBDE body burdens in local residents and can potentially threaten the health of infants. RECOMMENDATIONS AND PERSPECTIVES: Control measures should be imposed to minimize the level of pollutants resulting from e-waste processing operations to the environment and to humans. In-depth investigations on epidemiological studies of health impacts caused by e-waste recycling operations should be conducted. It is recommended that further measurements of PBDE levels in local food (e.g., fish, shellfish, dairy products, meat, fruits, and vegetables), dust, air, water, and human specimens be collected from a larger sample size at the e-waste processing site for the determination of human exposure pathways to PBDEs.

Body loadings and health risk assessment of polychlorinated dibenzo-p-dioxins and dibenzofurans at an intensive electronic waste recycling site in China.

This study is one of the very few investigating the dioxin body burden of a group of child-bearing-aged women at an electronic waste (e-waste) recycling site (Taizhou, Zhejiang Province) (24 +/- 2.83 years of age, 40% were primiparae) and a reference site (Lin'an city, Zhejiang Province, about 245 km away from Taizhou) (24 +/- 2.35 years of age, 100% were primiparae) in China. Five sets of samples (each set consisted of human milk, placenta, and hair) were collected from each site. Body burdens of people from the e-waste processing site (human milk, 21.02 +/- 13.81 pg WHO-TEQ1998/g fat (World Health Organization toxic equivalency 1998); placenta, 31.15 +/- 15.67 pg WHO-TEQ1998/g fat; hair, 33.82 +/- 17.74 pg WHO-TEQ1998/g dry wt) showed significantly higher levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/ Fs) than those from the reference site (human milk, 9.35 +/- 7.39 pg WHO-TEQ1998/g fat; placenta, 11.91 +/- 7.05 pg WHO-TEQ1998/g fat; hair, 5.59 +/- 4.36 pg WHO-TEQ1998/g dry wt) and were comparatively higher than other studies. The difference between the two sites was due to e-waste recycling operations, for example, open burning, which led to high background levels. Moreover, mothers from the e-waste recycling site consumed more foods of animal origin. The estimated daily intake of PCDD/Fs within 6 months by breastfed infants from the e-waste processing site was 2 times higher than that from the reference site. Both values exceeded the WHO tolerable daily intake for adults by at least 25 and 11 times, respectively. Our results implicated that e-waste recycling operations cause prominent PCDD/F levels in the environment and in humans. The elevated body burden may have health implications for the next generation.