Monitoring of selected polyhalogenated hydrocarbons in breast milk:: Czech Republic, 1994 to 2001

This study reports the concentration levels of indicator congeners of PCBs (IUPAC numbers 28, 52, 101, 118, 138, 153, and 180) in breast milk of women living in four districts of the Czech Republic with different levels of industrialization. From 1994 to 2000, altogether 2595 milk samples were analyzed, each year about one handred samples or less per district. A questionnaire was used to obtain information regarding basic personal characteristics and life style. PCB 138, 153 and 180 were the prevailing indicator congeners in human milk fat. Therefore, total PCB content was calculated by multiplying the sum of the congeners 138, 153 and 180 by factor 1.7. In the four monitored locations the median levels of PCBs were 1355 ng/g fat in 1994 and 653 ng/g fat in 2000. The results indicated a significant decreasing trend in time. Regional differences were found with the significantly higher PCB levels in samples from the location Usti n. L. (nad Labem) in comparison to other monitored locations. Besides, PCDDs, PCDFs and dioxin-like PCBs were analyzed in pooled milk samples prepared from individual samples collected in 1998, one pooled sample from each of the four districts. The overall WHO-TEQ values ranged from 29.6 pg/g fat in Zdar n. S. (nad Sazavou) to 35.3 pg/g fat in Usti n. L. The contribution of dioxin-like non-ortho (IUPAC nos. 77, 126 and 169) and mono-ortho IUPAC nos. 105, 114, 118, 123, 156, 157, and 189) PCBs to the total WHO-TEQ value was in the range of 60.1 to 68.5 % with PCB 126 and 156 as the main contributors.