Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Symposium Abstracts
Background and Objective:
Polychlorinated biphenyls (PCBs) are ubiquitous persistent pollutants whose role in developmental toxicity is of concern. Their kinetics in infants has not been thoroughly described yet.
A cohort study (1134 mother-infant pairs) was initiated in 2002, whereby organochlorines were measured in maternal and cord serum samples and in children at 6, 16, and 45-months using high resolution gas chromatography. The present analysis is based on a subgroup of 480 subjects living in Michalovce area.
In mother serum the CB-153 concentration was 2.34 ± 1.92 (mean ± SD) and 1.70 (median) ng/ml and 224.2 ± 175.4 (mean ± SD) and 175.4 (median) ng/g lipids. In decreasing order, congeners CB 153, 180, 138+163 and 170 were the major contributors to total PCB concentrations in serum. The highest sum of PCB serum concentration was at 6 months reflecting uptake through breast feeding. PCB sum levels decreased between the 6th and 16th month by 16% and from the 16th to 45th month by 9.7%. The most abundant pesticide in serum was pp-DDE, which peaked at 16 months of age. The cord and mother blood concentrations of all analytes correlated well except β-HCH. The ratios of cord:mother for means of analytes were higher than medians, except for pp-DDT, and they were <1 for sum of PCB congeners, CB 153, 138+163, DDE and HCB, indicating concentration equilibrium between lipids in mother and cord plasma. For less abundant congeners, DDT and β-HCH ratios were <1. The 6-month infant:cord ratios reflect uptake of organochlorines by breast feeding.
These unique longitudinal data are being used for exposure metrics (AUC, MRT) in association with various health outcomes. Further observation of the cohort is planned.