Background: Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected ofcarcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute to this difference.
Objective: To determine whether increased blood plasma concentrations of PCB 28 in Danish school children andmothers are associated with living in homes or attending schools constructed in the PCB period (1959–1977).
Methods: PCB 28 was analyzed in plasma samples from 116 children aged 6–11 years and 143 mothers living inan urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstrationof a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs wereused in construction in the period 1950–1977, and year of construction or renovation of the homes and schoolswas used as a proxy for indoor PCB exposure. Linear regression models were used to assess the association betweenpotential PCB exposure from building materials and lipid adjusted concentrations of PCB 28 in plasma,with and without adjustment for potential confounders.
Results: Among the 116 children and 143 mothers, we were able to specify home construction period in all but 4children and 5 mothers leaving 111 children and 138 mothers for our analyses. The median lipid adjusted plasmaPCB 28 concentration was 3 (range: 1–28) ng/g lipid in the children and 2 (range: 1–8) ng/g lipid in the mothers.Children living in homes built in the PCB period had significantly higher lipid adjusted plasma PCB 28 concentrationscompared to children living in homes built before or after the PCB period. Following adjustment for covariates,PCB 28 concentrations in children were 40 (95% CI: 13; 68) percent higher than concentrations of childrenliving in homes constructed at other times. Furthermore, children attending schools built or substantiallyrefurbished in the PCB period also had significantly higher (46%, 95% CI: 22; 70) PCB 28 concentrations comparedto children attending schools constructed before or after the PCB period, while their mothers had similar concentrations.Adjustment for the most prevalent congener, PCB 153, did not change this effect of home or school construction.When both home and school construction year were included in the models, the increase in lipidadjusted plasma PCB 28 for children living in or attending schools from the PCB period was no longer statisticallysignificant. The individual effect of home and school construction periods could not be evaluated further with theavailable data.
Conclusion: Our results suggest that PCB exposure in the indoor environment in schools and homes constructedduring the PCB period may contribute significantly to children's plasma PCB 28 concentration. Efforts to minimizePCB exposure in indoor environments should be considered.