Current exposure to persistent polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (p,p'DDE) of Belgian students from food and dust

Human exposure to individual polychlorinated biphenyl (PCB) congeners and dichloro-diphenyldichloroethylene (p,p'-DDE) through food (duplicate diets) and indoor dust ingestion was assessed for 19 Belgian students. The serum concentrations of the persistent PCB congeners in serum (PCB 118, 138, 153, 170, and 180) have been correlated with the individual intake through food and dust Dietary intakes of Sigma PCBs ranged between 40 and 204 ng/day (median 133). PCB exposure through dust ingestion ranged between 0.1 and 0.8 ng/day (median 0.3) or 0.3 and 1.7 ng/day (median 0.8), assuming average dust ingestion (20 mg/day) and high dust ingestion rates (50 mg/day), respectively. Dietary intake of p,p'-DDE was comparable to that of PCBs with a range from 21 to 214 ng/day (median 92). The exposure to p,p'-DDE via dust ingestion ranged between 0.02 and 0.43 ng/day (median 0.17) or 0.05 and 1.09 ng/day (median 0.43), assuming average and high dust ingestion rates, respectively. Concentrations measured in blood serum were 28-153 ng/g lipid weight (lw) (median 74) and 32-264 ng/g lw (median 45) for Sigma PCBs and p,p'-DDE, respectively. Serum concentrations in the studied population are slightly lower compared to other European populations. In spite of the uncertainty associated with the dust ingestion rates, food was the predominant exposure pathway for each PCB congener and for p,p'-DDE in the studied population. Food intake contributed more than 99% of the combined PCB intake from food and dust. No significant positive correlations (p > 0.05) were observed between the serum concentrations of PCBs and p,p'-DDE and the total intake through food and dust for each participant. Instead, it is hypothesized that past and episodic higher current intakes are more important determinants of body burden than continuous background exposures at low levels.