Polychlorinated biphenyls in the blood of personnel from an electric utility.

Because polychlorinated biphenyls (PCBs) have been implicated as potentially toxic to humans and because the electric utility industry is thought to have significant opportunity for occupational exposure, a study was performed to identify electric utility personnel with the highest PCB exposure potential and to assess their current blood PCB concentrations. For currently employed personnel, a median PCB plasma value of 3 ppb with a mean of 4 +/- 3.65 ppb was found; for a preemployment sample the median was 4 ppb with a mean of 5 +/- 4.25 ppb. PCB concentrations in blood of these personnel are similar to concentrations reported for other populations without occupational exposure. No adverse health impacts would be expected to result from these blood concentrations. These data indicate that no significant occupational exposure has occurred in this utility. This study shows the importance of assessing exposure potential at specific worksites prior to making general exposure or hazard assessments.