PCBs and cognitive functioning of Mohawk adolescents.

This paper reports on the relationships between the cognitive functioning and PCB current body burdens of adolescents in the Mohawk Nation of Akwesasne where there is concern about industrial pollution of the environment. Three cognitive tests (Woodcock Johnson-Revised, Test of Memory and Learning, and Ravens Progressive Matrices) provide 13 subtests that allow a variety of cognitive outcomes to be assessed. A summary measure of PCB level was created from the congeners detected in at least 50% of the participants. The most notable finding was the significant negative relationship between PCB levels and two separate measures of long term memory. There was also a negative relationship with a measure of comprehension and knowledge. Significant relationships were not large, but provide evidence of subtle negative effects of PCB exposure.

Organochlorines, lead, and mercury in Akwesasne Mohawk youth.

Most humans have detectable body burdens of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and p,p'-dichlorophenyldichloroethylene p,p'-DDE), a metabolite of p,p'-dichlorodiphenyltrichloroethane (DDT). Native American communities may be at increased risk of exposure through subsistence-based diets and greater physical contact with contaminated soil and water. In this article we describe the levels of toxicants (PCBs, p,p'-DDE, HCB, mirex, lead, and mercury) among youth 10-17 years old (n = 271) of the Akwesasne Mohawk Nation. Ultratrace, congener-specific PCB analysis of human serum quantitated 83 PCB congeners (plus 18 as pairs/triplets), in addition to p,p'-DDE, HCB, and mirex, and included all major Aroclor-derived congeners typically present in human samples. Twenty congeners (in 16 chromatographic peaks) were detected in 50% or more of the individuals sampled [geometric mean (GM) of the sum of these congeners = 0.66 ppb]. Thirteen congeners (in 10 peaks) were detected in 75% or more of the samples (GM = 0.51 ppb). Of the 20 congeners detected in 50% or more of the samples, 17 had five or more chlorine substitutions. International Union for Pure and Applied Chemistry congeners 118, 101(+90), and 153 were detected in nearly all participants (GM = 0.06 ppb, 0.05 ppb, 0.09 ppb, respectively). p,p'-DDE and HCB were detected in 100% and 98% of the samples (GM: p,p'-DDE = 0.37 ppb; HCB = 0.03 ppb). Mirex was detected in approximately 46% of the samples (GM = 0.02 ppb). No cases of elevated lead level were observed. One participant had a mercury level marginally higher than the U.S. Environmental Protection Agency's current level of concern (0.50 microg/dL). Although differences in analytic methods and participant ages limit comparability, toxicant levels from the Mohawk youth are lower than those associated with severe food contamination (Yusho and Yu-cheng) but similar to other chronically exposed groups.

Fish consumption and other environmental exposures and their associations with serum PCB concentrations among Mohawk women at Akwesasne.

A study was conducted with the objective of assessing how dietary, occupational, and residential exposures to polychlorinated biphenyls (PCBs) contribute to body burden among pregnant Mohawk women residing near three hazardous waste sites. From 1992 to 1995, 111 pregnant women were interviewed about fish consumption and other environmental risk factors and donated a 20-mL venous blood sample for serum PCB analysis. To supplement previous fish sampling, samples of residential soil, ambient air, wild duck, and local meats and vegetables were also collected and analyzed for PCBs. The results indicated a significant decline in local fish consumption from an annual mean of 31.3 meals more than 1 year prior to pregnancy to an annualized mean of 11.7 meals during pregnancy. This change was reportedly a result of the advisories issued against consumption of local fish by pregnant and nursing women of childbearing age. The geometric mean concentration of total PCBs in the serum was 1.2 ppb, a level that is similar to that in other studies of women with no unusual exposures to PCBs. However, multiple regression analysis revealed that serum levels of total PCBs and three individual congeners were associated with local fish consumption. The PCB levels in soil, air, and local foodstuffs other than fish generally were not elevated, except for those obtained in close proximity to one of the hazardous waste sites, and no association was found between serum PCB levels and exposure through these media or through occupation.