PCB exposure during remediation and demolition of contaminated buildings: Full congener analysis and effects of hygiene measures

Several residential buildings in Denmark were highly contaminated with polychlorinated biphenyls (PCBs), exceeding indoor air guidance values, and were set for demolition. We conducted a comprehensive evaluation of occupational exposure to PCBs during the demolition process using personal and stationary air sampling, hand and surface wipes, t-shirts, and glove wipes, and compared them to previously analyzed silicone wristbands and the original PCB sealant source. We further evaluated the utility of hygiene measures like handwashing for reducing exposure. Samples were analyzed for all 209 PCBs via microwave-assisted extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS), and > 140 PCB features (individual congeners and co-elutions) were detected in at least one sample. Overall, tetra-CBs were the dominant homolog group across all samples, but the most abundant individual congeners depended on the sample matrix, with lower chlorinated PCBs being more prominent in air compared to wipes and wristbands. Levels of personal exposures were highly task-specific, with workers who cut the PCB-containing sealants having the highest exposure across sample types. Handwashing was shown to reduce PCB levels on workers' hands, while PCBs were also observed to permeate typical textile work gloves and worn t-shirts showed varying degrees of contamination. Across all sample types, total congener analysis demonstrated that traditional indicator-based calculations underestimated total PCB content by 25% or more. Overall, our results indicated that personal protective equipment and simple hygiene can reduce exposure, and demolition workers have high potential for PCB exposure when handling contaminated materials, necessitating careful exposure mitigation and task-specific controls.