Abstract
Polychlorinated biphenyls (PCBs) have been used in the electrical industry for almost 50 years, primarily as an insulating fluid in transformers and capacitors. NIOSH has estimated that as many as 100 000 electrical workers are occupationally exposed to PCBs. The purpose of this study was to assess maintenance electrician exposure to PCBs during transformer maintenance, and to determine pre- and post-maintenance ambient PCB concentrations to which other building inhabitants might be exposed. Breathing-zone PCB concentrations during the maintenance of the transformer and in surrounding areas ranged from 2.1 to 60.0 µg/m3. Background PCB concentrations ranged from 0.2 to 0.9 µg/m3 in the transformer room, and from nondetectable to 0.6 µg/vn3 in areas immediately outside the trnasformer room. During maintenance operations, PCB concentrations ranged from 1.9 to 55.0 µg/m3 in the transformer room, and from nondetectable to 1.4 µg/m3 outside the transformer room, but eventually declined to pre-maintenance levels.