Exposure assessment of breast-fed infants in the Czech Republic to indicator PCBs and selected chlorinated pesticides: Area-related differences

The aim of our study was to obtain data on the exposure of breast-fed infants to polychlorinated biphenyls (PCBs) and selected organochlorine pesticides (OCPs) in different urban areas of the Czech Republic. The PCB and OCP levels were determined in 90 human milk samples collected in seven urban areas in 1999–2000 according to the WHO protocol. The estimated daily intake (EDI) was calculated for each of the analytes and compared with the respective tolerable daily intake (TDI). Significant local differences in the sum of 35 PCB congeners analyzed (total PCBs) as well as in the most prominent indicator congeners 138, 153, and 180 values were observed, with the highest levels being found in breast milk samples from mothers living in the vicinity of a former plant using PCBs in Uherské Hradiště (median and ranges 3410 and 1448–13 754 ng g−1 lipid weight (lw)). Non-exposed mothers from the same area had about threefold lower levels (median and ranges 1073 and 757–2139 ng/g lw, respectively). The lowest levels of total PCBs were found in Telč (median and ranges 480 and 293–731 ng g−1 lw, respectively). In all study areas, EDIs for PCBs in breast-fed infants exceeded the TDI of 0.4 μg kg−1 bw d−1 recommended in the Czech Republic. EDI for HCB exceeded the recommended TDI of 0.16 μg kg−1, EDI for DDT was slightly below TDI of 10 μg kg−1 bw d−1 and HCHs EDI was negligible. The database of analytical results from this study was used for Bayesian modeling of breast-fed infant exposure to PCBs and OCPs during the recommended 6 months of exclusive breastfeeding.