PCBs in indoor air, and in blood of residents

Introduction
Polychlorinated biphenyls (PCBs) were used as plasticizers in various building materials, particularly caulks, in Danish buildings from the 1950s to the mid 1970s. Common to all PCBs in building materials is, that even after several decades’, considerable amounts of them are still being released into the air. They are resistant to environmental degradation and accumulate in the environment, in the food chain and in humans. Registered health effects include damage to skin and reproduction, and PCBs are furthermore suspected of affecting the liver, thyroid glands, immune and endocrine systems, and of being carcinogenic.

Methods
For the Farum Midtpunkt housing estate, which was constructed over a three-year period, whole buildings were constructed either with or without caulks containing PCBs. This is a stratified, cross-sectional study including 289 participants over the age of 18, 137 from apartments with caulks containing PCBs and 152 from apartments without PCBs in the caulks. A questionnaire concerning age, the number of years spent at the estate, tobacco consumption (tobacco smoke contains PCBs), intake of selected foodstuffs (fish, meat and dairy products), for the women their number of births and the number of months they have nursed each child (breastfeeding reduces the levels of PCBs in women). 
Blood samples will be analyzed for the PCB indicator congeners (PCB 28, 52, 101, 138, 153, 180), for dioxin-like PCBs (PCB 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) and for 9 additional PCBs (PCB 66, 74, 99, 170, 178, 182, 183, 187, 190). 24-hour air samples are analyzed for the same congeners except #172, 182 and 190. 

Results
Laboratory results will be ready in August 2011, and PCB levels will be presented according to PCB exposure, gender, child nursing, smoking habits and diets, and for association to indoor air levels.

Discussion
To follow