Activity-based exposure levels and lifetime cancer risk for workers exposed to polychlorinated biphenyls during electronic waste dismantling in Buriram province, Thailand

Abstract

The activity-based exposure concentrations of airborne polychlorinated biphenyls (PCBs) for electronic waste (e-waste) dismantling workers in Buriram province were examined, and their possible carcinogenic risk was assessed. The average exposure concentration of total PCBs in the particle (PM2.5–10 and PM2.5) and gas phases were 53.51 ± 23.68, 65.41 ± 23.06, and 82.72 ± 78.61 ng/m3, respectively, and were all significantly (p < 0.05) higher for workers exposed during burning wires than those of the dismantling bulky-, small-, and internal e-waste parts. The dominant PCB congeners mainly found during e-waste dismantling were the low-chlorinated group, including PCB-28, -52, −77, −81, −105, −118, and −126. PCB-28 and -77 were observed as predominant co-congeners derived from mechanical dismantling, whereas PCB-52, -118, and −126 were the main species emitted from burning activities. The workers exposed to PCBs from burning wires were estimated to have the highest lifetime cancer risk of 1.64E-05, about 2.5- to 3.3-fold higher than those who dismantled bulky-, small- and internal e-waste parts. Consequently, workers should be recommended to wear high-efficiency respiratory protection masks to avoid direct exposure to PCBs and to reduce their possible carcinogenic risk.