Polychlorinated biphenyl concentrations in the blood plasma of a selected sample of non-occupationally exposed southern California working adults.

Blood samples from 738 employees of the Southern California Edison Company were analyzed for PCBs prior to their starting work, as part of a pre-employment medical examination. Blood PCB concentrations of the pre-employment sample had a median of 4 ppb and a mean of 5 +/- 4 ppb. These data are comparable to previously published values for blood PCB concentrations in people without occupational exposure. Plasma PCB concentrations are also sorted by demographic characteristics of the sample (age/race/sex/education). Since the demographic properties of the newly hired employees are reasonably similar to those of the Los Angeles-Long Beach work force, as determined in the 1980 census, we conclude that the low PCB concentrations present in the blood of a sample of new electric utility employees is representative of the regional work force and arise from exposures to PCBs present in the general environment.