Human biomonitoring of polychlorinated biphenyls (PCBs) in plasma of former underground miners in Germany - A case-control study

Highly significant differences between cases and age-matched controls were only found for the PCB-congeners PCB 74 and PCB 114. The median (95th percentile) levels of PCB 74 in cases and controls were 0.126 μg/L plasma (0.899 μg/L plasma) vs. 0.058 μg/L plasma (0.368 μg/L plasma) and the 95th percentile levels for PCB 114 were 0.039 μg/L plasma vs. 0.017 μg/L plasma. Linear regression models revealed that this difference in plasma levels was unequivocally attributed to the underground mining activity. Thus, retrospective exposure assessment for underground miners by use of human biomonitoring seems feasible and further studies with a particular focus on this special group of workers should be performed.