Assessment of prenatal exposure to PCBs from maternal consumption of Great Lakes fish: an analysis of PCB pattern and concentration.

The current study was designed to assess the pattern and concentration of prenatal PCB exposure in the newborns of women who consumed Great Lakes fish. We compared the pattern and concentration of umbilical cord blood PCBs of 145 women who reported never having consumed Great Lakes fish to 134 women who reported consuming at least 40 PCB-equivalent fish lbs of Great Lakes fish in their lifetime (Lonky et al., 1996). Although the average levels of total PCBs in cord blood were exceedingly low (approximately 1.0 ppb), the data clearly indicated that both the proportion (mol%) and the absolute concentration (ppb) of the most heavily chlorinated and persistent PCB homologues (homologues C17-C19) were markedly elevated in the cord blood of fish eaters. This effect grew markedly as a function of the total PCBs detected in the sample. Moreover, the concentration of the most heavily chlorinated PCB homologues was significantly dependent on how recently the fish were consumed relative to pregnancy. The order of highly chlorinated PCB concentration was consumed fish throughout pregnancy > consumed fish up until pregnancy > stopped consuming fish in 1984 > never consumed Lake Ontario fish. In contrast, PCB homologues of light (Cl1-Cl3) or moderate (Cl4-Cl6) chlorination were unrelated to fish consumption. Analysis of the relationship between the PCB homologues in cord blood and their homologues in breast milk provided further converging evidence of these findings. While PCB homologues of light (Cl1-Cl3) or moderate (Cl4-Cl6) chlorination did not correlate with their breast milk homologues, the most persistent and heavily chlorinated PCB homologues (Cl7-Cl9) were significantly and positively correlated with breast milk levels. These data indicate that the most heavily chlorinated PCBs provide valid and reliable exposure information in a lean medium such as cord blood. We conclude that maternal consumption of Great Lakes fish increases the risk of prenatal exposure to the most heavily chlorinated PCB homologues. Copyright 1999 Academic Press.