| Electrical and electronic waste (E-waste) has become the fastest growing stream among all the solid waste around the worldwide with the development of the electronic information technology. Environmental pollution arising from e-waste disposal and recycling facility has received considerable attention in recent years in China. Approximately, 20-50 million metric tons of e-wastes are produced worldwide every year, if which 70% is exported to China for recycling. Taizhou has become one of the largest recycling centers in China which employes around 40000 people for recycling, and approximately 2.2 minllion metric tons of e-wastes are dismantled there annually. Treatment, at low temperatures, of e-waste, that contain polyvinylchloride and related polymers can release persistent halogenated hydrocarbons (PHHs), such as polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and parent polycyclic aromatic hydrocarbons (PAHs). Nevertheless, little is known about the concentrations, profiles, and estimated human exposures for these PHHs from e-waste recycling facility in China.In this study, reliable analysis and instrument methods were built up. Electronic shredder waste, workshop-floor dust, leaves, surface soil and human hair sample of the recycling workers collected from a large scale e-waste recycling facility in Taizhou, eastern China, were analyzed for these PHHs. At the same time, surface soils from agricultural areas in eastern and central China were also collected as the background comparison, and surface soils from an traditional chemical industrial complex in Shanghai were collected as different functional area comparison in order to show the characteristic persistent organic pollutants in e-waste recycling facility.10 PBDE congeners were detected all samples, the highest mean concentration of PBDEs were found in electronic shredder waste (45500 ng/g dw), and the highest value was even 163000 ng/g dw. The mean concentration of total PBDEs in soil from the e-waste facility was approximately 2 orders of magnitude higher than the concentrations in soils from the chemical industry complex and approximately 3 orders of magnitude higher than the concentrations in agricultural soil, suggesting that a major emission source of PBDEsis the low-tech e-waste recycling facilities. The PBDEs profiles in our samples were comparable with the commercial penta-BDE and deca-BDE products, which showed the brominated flame retardants employed in electrical and electronic appliances were the major emission source during the low-tech recycling facility.PCDD/Fs congeners were detected all samples, concentrations of total PCDD/Fs were highest in workshop-floor dust (1240～111000 pg/g dw,mean, 39800 pg/g dw). The mean concentration of total PCDD/Fs in soil from the e-waste facility was approximately 12 times higher than the concentrations in soils from the chemical industry complex and approximately 200 times higher than the concentrations in agricultural soil. The profiles of PCDD/Fs in our samples were similar with the profiles of other PCDD/Fs emission sources reported in the literatures. PBDD/Fs were only detected in samples from e-waste recycling facility, which suggested PBDD/Fs were the new characteristic persistent organic pollutants in low-tech e-waste recycling facility. The profiles of PBDD/Fs were similar with the chlorinated dioxins and furans, and the TEQ values of PBDD/Fs were higher than those of PCDD/Fs in most samples. We suggested the low-tech e-waste recycling facility was the major emission source of chlorinated and brominated dioxins and furans.We also firstly reported the 100% detection of ClPAHs in multiple samples from e-waste recycling facility. The mean concentration of total PCDD/Fs in soil from the e-waste facility was approximately 178 times higher than the concentrations in agricultural soil, and the concentrations in soils from the chemical industry complex were comparable with the concentrations in multiple samples from e-waste recycling facility. Concentrations of 16 parent PAHs were high (150～49700 ng/g dw) in samples collected from the e-waste recycling facility. Significant correlation betweenΣClPAH andΣPAH concentrations suggests that direct chlorination of parent PAHs is the major pathway of formation of ClPAHs during e-waste recycling operations. We predicted the chemical and physical characters of 20 ClPAHs and their fate in environment by QSAR and multimedia fugacity model LevelⅢ, which suggested the toxicity of ClPAHs could increase with the increasing chlorination level, and ClPAHs having the similar fate with dioxins could be ready to accumulate in soil and sediment in standard environment. The TEQ concentrations of ClPAHs found in multiple environmental matrices in this study were higher than the TEQ concentrations of PCDD/Fs and PBDD/Fs in the same samples. We suggested the low-tech e-waste recycling facility was the major emission source of chlorinated PAHs, and so did in chemical industrial complex.The concentrations of PBDEs and PCDD/Fs in recycling workers'hairs were higher than those in residents'hairs. The Profiles of PBDEs and PCDD/Fs in hairs from recycling worker were comparable with those in hairs from residents, suggested the PBDEs and PCDD/Fs in human hairs were mainly exotic pollution.Combined pollution effect of five PHHs could be paid more attention because of the elevated concentrations, high TEQ values, and the significant correlations among each others.VlIER-HUMAAN model was applied to calculated the estimated daily intakes of TEQs of PBDEs, PCDD/Fs, PBDD/Fs, ClAPHs, and parent PAHs via non-dietary exposure pathways. And the results showed that the estimated daily intakes from soil/dust ingestion > that from dermal absorption > that from particulate inhalation. The estimated daily intakes of PCDD/Fs were very close to the upper bound of WHO 1998 tolerable daily intake (TDI, 1～4 pg TEQ/kg bw/day), and the estimated daily intakes of PBDD/Fs were 2 times higher than TDI. Hazard index (HI) of PCDD/Fs for children was 2.25, qualitative descriptor suggested low noncancer toxic risks, and HI of PCDD/Fs for children was 0.222, qualitative descriptor suggested minimal noncancer toxic risks. The estimated daily intakes of BDE 99 exceeded the tolerable daily intake from reference about 2 times. All of the calculated risk of ClAPHs and parent PAHs were deemed acceptable risk level. |
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