Z. Z. Yang

Dual body burdens of polychlorinated biphenyls and polybrominated diphenyl ethers among local residents in an e-waste recycling region in Southeast China

E-waste recycling resulted in serious pollution of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Taizhou of Zhejiang Province, China. The aims of this study were to assess dual body burdens of the two pollutants and potential health risk for local residents. Blood samples were collected from two e-waste recycling sites, Luqiao (where PCBs-containing e-wastes were recycled) and Wenling (where PBDEs-containing e-wastes were recycled). The mean summation SigmaPCBs (CB-105, 118, 153, 183, and 180) and summation SigmaPBDEs (BDE-28, 47, 99, 100, 153, 154, 180, and 209) were 204.20 and 117.58 ng g(-1) lipid in the blood from Luqiao, respectively, while they were 83.80 and 357.44 ng g(-1) lipid from Wenling, respectively. The PCBs levels among Luqiao residents were comparable to the values reported for US populations, while the PBDEs levels among two study populations were higher than the values from US populations. This is the first report to present dual body burdens of PCBs and PBDEs at so high levels. Based on previous epidemiologic data, it is suggested that dual burdens of PCBs and PBDEs at so high levels might pose health risk for local residents. In addition, no correlation between PCBs or PBDEs concentrations and the ages of the volunteers was observed in the two populations, which was explained by similar exposure time. No correlation of PBDEs with PCBs concentrations suggested different pathways of human exposures to PCBs and PBDEs. Our findings have raised concern about human health risk of dual exposure to PCBs and PBDEs resulting from e-waste recycling.

Polybrominated diphenyl ethers in leaves and soil from typical electronic waste polluted area in South China

Polybrominated diphenyl ethers (PBDEs) in leaves and soil from typical e-waste polluted area in South China were investigated. The concentrations (ng/g dry weight) of PBDE congeners and ∑PBDE of five leaf samples were much lower than those in soil sample. The general patterns of ∑di-BDEs to ∑hepta-BDEs percentage distribution in leaf samples were similar to those of the soil sample, except the percentage of BDE209 which were lower than in soil. The percentages of ∑di-BDEs to ∑hepta-BDEs in soil were in the range of those in leaf samples. The results showed that the contamination of PBDEs in the leaf samples had good correlation with the soil around them.

Levels and distribution of polybrominated diphenyl ethers in various tissues of foraging hens from an electronic waste recycling area in South China

Levels and distribution of polybrominated diphenyl ethers (PBDEs) in various tissues of hens foraging near an electronic wastes stack spot in Taizhou, China, were studied. With high-resolution gas chromatography/negative chemical ionization mass spectrometry analysis, 37 PBDE congeners from di- to hepta-brominated and BDE 209 were identified and quantified in the liver, heart, skin, fat, intestine, muscle, blood, oviduct, ovum, gizzard, spleen, and kidney tissues of hens. Based on lipid weight in all analyzed tissues, muscle exhibited the highest PBDE concentrations (17,977 ng/g lipid wt), BDE 209 was the dominant congener, and the sum of quantified PBDEs followed the order muscle > fat > intestine > heart > liver > oviduct > gizzard > blood > skin > ovum. Principal component analysis results indicated that the hen muscle tissue was characterized by BDE 32, 209, 28, and 75 congeners; hen intestine, heart, and blood tissues were characterized by BDE 153, 99, 183, 138, 154, 47, and 100 congeners; and hen skin, liver, oviduct, ovum, gizzard, spleen, kidney, and fat tissues had a similar PBDE congener profile. The present study also indicated that the PBDE congeners were persistent enough to accumulate through the human food chain and that deca-BDE might be potential risk to ecoenvironment.

Spatial character of polychlorinated biphenyls from soil and respirable particulate matter in Taiyuan, China

As one of Chinas great metropolises, Taiyuan is affected by heavy chemical industry and manufacture of chemical products, and faces pollution from polychlorinated biphenyls (PCBs). Therefore, this study was conducted to determine the PCB concentrations in various environmental media in Taiyuan. We collected 15 soil samples, 34 respirable particulate matter (PM) samples (17 of PM(2.5) and 17 of PM(10)) from urban areas of Taiyuan, and measured a total of 144 PCB congeners (including some coeluting PCB congeners). The total PCB concentrations were 51-4.7 x 10(3) pg g(-1) in soil, 27-1.4 x 10(2) pg m(-3) in PM(2.5) and 16-1.9 x 10(2) pg m(-3) in PM(10). Of the PCB homologues, the dominant PCBs detected in the various media were all tri-CBs. Soil was relatively the most polluted media. Furthermore, principal-component analysis revealed that the major PCB source in Taiyuan may be associated with the main commercial PCB through long-range transmission. Toxic equivalency (TEQ) concentrations (based on ten dioxin-like PCBs) ranged from N.D. to 5.9 x 10(-3) pg-WHO TEQ g(-1) in soil, 2.0 x 10(-4)-3.4 x 10(-3)pg-WHO TEQ m(-3) and 1.0 x 10(-4)-1.2 x 10(-3) pg-WHO TEQ m(-3) in PM(2.5) and PM(10), respectively. In previous studies, PCBs were not a severe component of contaminant in Taiyuan; however, this study suggested there is a potential threat of human exposure to PCBs for residents of Taiyuan.

Thyroid disruption by technical decabromodiphenyl ether (DE-83R) at low concentrations in Xenopus laevis.

Decabromodiphenyl ether (decaBDE), as a flame retardant, is widely produced and used. To study the thyroid disruption by technical decaBDE at low concentrations, Xenopus laevis tadpoles were exposed to technical decaBDE mixture DE-83R (1-1000 ng/L) in water from stage 46/47 (free swimming larvae, system of Nieuwkoop and Faber) to stage 62. DE-83R at concentration of 1000 ng/L significantly delayed the time to metamorphosis (presented by forelimb emergence, FLE). Histological examination showed that DE-83R at all tested concentrations caused histological alterations - multilayer follicular epithelial cell and markedly increased follicle size accompanied by partial colloid depletion and increase in the peripheral colloid vacuolation, in thyroid glands. All tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA expression. These results demonstrated that technical decaBDE disrupted the thyroid system in X. laevis tadpoles. Analysis of polybrominated diphenyl ethers (PBDEs) (sum of 39 congeners) in X. laevis indicated that mean concentrations of total PBDEs in X. laevis exposed to 1, 10, 100, 1000 ng/L were 11.0, 128.1, 412.1, 1400.2 ng/g wet weight, respectively. Considering that PBDEs burden ofX. laevis tadpoles was close to PBDEs levels in amphibians as reported in previous studies, our study has raised new concerns for thyroid disruption in amphibians of technical decaBDE at environmentally relevant concentrations.

Polychlorinated biphenyl residues in sandstorm depositions in Beijing, China.

Sandstorms, which distribute many particles, are a special atmospheric occurrence and are frequent in northern China. We conducted this study to determine, for the first time, the concentration of polychlorinated biphenyls (PCBs) in sandstorm depositions. We collected 13 samples from urban areas of Beijing, and we measured a total of 144 PCB congeners. Thirteen samples all contained PCB residues. The total PCB concentration ranged from 1.6 to 15.6ngg(-1) (median, 4.8ngg(-1), dry weight), with trichlorinated biphenyls as the predominant homologue (>50.4%). Furthermore, we observed increasing PCB contamination from northwest to east Beijing. We later explored possible factors affecting contamination of the sandstorm depositions, which revealed a significant correlation between SigmaPCBs and the minimum particle size of the sandstorm deposition samples. Principal-component analysis revealed that the major source of PCBs in Beijing may be potentially associated with the number-one commercial PCB through the long-range transmission. In previous results, PCBs were not a severe component of contamination in sandstorm depositions of Beijing. However, this study suggested that sandstorm deposition may be a potential source of exposure to PCBs for the residents of Beijing, China.

Special Distribution of Polybrominated Diphenyl Ethers in Brain Tissues of Free-range Domestic Hens and Ducks from a Village near an Electronic Waste Recycling Site in South China

The rural village, Taizhou of Zhejiang Province, had been exposed to e-waste recycling for years, the polybrominated diphenyl ether (PBDE) levels in hens and ducks were high. The concentration of ∑PBDEs in the brain was the lowest among tissues of individual hens and ducks after correction for the respective lipid content. Also, the concentration ratio of BDE-153 versus BDE-154 (153/154) of brain was the highest among tissues of individual hens and ducks. Our results indicate that the hindrance of blood–brain barrier to compounds, such as high molecular weight and non-planar conformation (steric hindrance), contributed to the low concentration of PBDEs in the brain tissue of hens and ducks, especially in cases exposed to high levels of PBDE.

Contamination Status of Hexachlorobenzene (HCB) in Sandstorm Depositions from Beijing and the Origination Region

In China, sandstorms play an important role in the long-range atmospheric transport and deposition of hexachlorobenzene (HCB). Concentrations of HCB in sandstorm depositions sampled from Beijing and the origination region were measured to reveal HCB levels during atmospheric transport. The results suggested a constant level of HCB during atmospheric transport. The values were close to environmental background values indicating that no potential source of HCB existed along the transport route. A tendency for HCB levels in Beijing to increase from north to east was also observed, which was probably due to the influence of wind speed and industrial zone distribution.