Biological monitoring of indoor-exposure to dioxin-like and non-dioxin-like polychlorinated biphenyls (PCB) in a public building
Release of polychlorinated biphenyls (PCB) from sealant material in public buildings and resulting indoor air concentrations have raised growing concern about possible human health effects connected to this exposure. Ambient PCB monitoring in a public building showed a contamination with the more volatile lower chlorinated PCB-28, 52, and 101 congeners. This gave reason for a large biomonitoring study to examine the internal exposure of persons working in that building to PCB. Blood was drawn from 209 persons employed in the PCB-contaminated building; 98 age/gender matched persons working in non-contaminated buildings served as control group. Plasma was analysed for the 6 indicator PCB (28, 52, 101, 138, 153, 180) and 12 dioxin-like PCB by gas chromatography/mass spectrometry with a 0.01 íg/L limit of detection. Significant differences between both collectives were only observed for plasma concentrations of the lower chlorinated congeners (PCB 28, 52, 101) and dioxin-like congeners (PCB 105, 118), which were due to inhalative exposure to these congeners via indoor air. Median PCB 28, 52, and 101 plasma concentrations in employees of the contaminated building were 0.087, 0.024, and 0.012 íg/L, respectively. Concentrations of the higher chlorinated PCB and all other dioxin-like congeners were within the normal range of the general population. There was no relationship between indoor air measurements and internal exposure of employees in the corresponding office, but estimated lifetime exposure of employees was a significant factor for plasma PCB 28 concentrations. The authors concluded that the biomonitoring results served as a basis for individual risk communication and successful risk management.