Human Exposure Levels of Volatile Organic Compounds in E-waste Recycling Area: Get Insight into Impacts of Manipulation Mode and Associations with Oxidative Stress Markers.

There is currently a dearth of evidence regarding the impact of the manipulation mode on human occupational exposure to volatile organic compounds (VOCs) originating from e-waste dismantling. Therefore, 11 VOC metabolites (mVOCs) and four oxidative stress biomarkers (OSBs; i.e., 8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-oxo-7,8-dihydro-guanosine, 8-oxo-7,8-dihydroguanine, and dityrosine) were analyzed in urine collected from two disassembly regions. Urinary ∑mVOC concentrations were significantly higher for e-waste-related participants than controls (geometric mean: 2500 vs 1360 ng/mL; < 0.05). Notably, adults from formal dismantling site (3020 ng/mL) had equivalent ∑mVOC levels as those from informal area (2830 ng/mL) but with varying composition features, indicating that elevated exposure VOC levels still remained even e-waste is properly recycled. Majority of mVOCs were significantly correlated with OSB levels occurring in nucleotides and proteins, and weighted quantile sum regression analysis further manifested that urinary metabolites of 1,3-butadiene and dimethylformamide occupied the highest contributions to the positive responses of measured OSBs. The hazard quotients of 1,3-butadiene and benzene were greater than one for more than 80% of participants, implying the potential health risk associated with e-waste dismantling. Thus, this study provides crucial information on e-waste-related priority VOCs of various recycling practices for management to mitigate their health risks.