Comparability and Precision of Serum PCB Measurements

Abstract

The 95% prediction interval for single measurements of serum “Aroclor” reported by a reputable commercial analyst was found to be approximately ± 42%. The geometric mean serum PCB levels in a population of capacitor workers who had formerly had direct exposure to the commercial PCBs-Aroclors 1016, 1242, and 1254—were found to be alternatively reportable as 1905 ppb minimum initial PCBs (as calculated from most persistent peaks present); 1093 ppb non-overlapping analytical “Aroclor” levels (as calculated by the conventional sum-of-the-peak-heights method); 303 ppb total PCBs actually present; or 19 ppb “human PCB” (as calculated by the NHMP procedure). The broad spread in reportable values was relatable to the PCB isomer distribution and clearance patterns in the occupationally exposed population.