文摘
Indoor air levels of coplanar polychlorinated biphenyls(mono- and non-ortho substituted PCB) of various buildingswere determined. As a consequence of the presence ofjoint sealings containing PCB, total PCB concentrations inindoor air up to 4200 ng/m3 were detected (data basedon a survey including 29 sampling sites). In a PCBcontaminated industrial building, total indoor air PCBlevels up to 13000 ng/m3 were measured. Typical PCBcongeners in indoor air include PCB 28, PCB 52, and PCB101. Concentrations of coplanar (dioxin-like) PCB havebeen determined for six different sites. The most abundantcoplanar PCB congener in indoor air is PCB 118, followedby PCB 105, PCB 123, and PCB 77 in various order.Levels of coplanar PCB, expressed as toxicity equivalents(TEQ), do correlate well with the total indoor air PCBconcentration: a total PCB level of 1000 ng/m3 correspondsto a concentration of coplanar PCB of 1.2 pg TEQ/m3.Based on this correlation and on an indoor air PCB levelof 6000 ng/m3 (tentative guideline value for PCB in indoor airin Switzerland based on a daily exposure of 8 h), themaximum daily intake of coplanar PCB via indoor air wasestimated to be 0.6 pg TEQ/kg body weight.