The association between local fish consumption and DDE, mirex, and HCB concentrations in the breast milk of Mohawk women at Akwesasne.

A study was conducted to assess the extent to which the consumption of local fish contaminated with p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE), mirex, and hexachlorobenzene (HCB) has impacted the concentrations of these compounds in the milk of nursing Mohawk women residing along the St. Lawrence River. From 1986 to 1992, 97 Mohawk women were interviewed, and each donated a one-time sample of at least 50 ml of breast milk. The comparison population consisted of 154 Caucasians from other rural areas in New York State. After adjustment for potential confounders, Mohawk mothers who gave birth from 1986 to 1990 had significantly higher geometric mean p,p'-DDE milk concentrations than did the control group, but no significant differences were observed from 1991 to 1992. In contrast, mirex was significantly elevated among the Mohawks throughout the study period, while HCB showed no difference at any point. Mohawk women with the greatest estimated cumulative lifetime exposure to p,p'-DDE from local fish consumption had a significantly higher geometric mean milk level of that compound relative to control women, but no differences in mirex or HCB concentrations in breast milk by local fish consumption were found. The reduction in breast milk p,p'-DDE concentrations among the Mohawk women from 1986 to 1990 parallels a corresponding decrease in local fish consumption, and may be the result of the advisories that have been issued over the past decade recommending against the consumption of local fish by pregnant and nursing Mohawk women. Elevations in the concentrations of mirex in the breast milk of the Mohawks are consistent with the fact that it is a common contaminant in the region and throughout the Lake Ontario-St. Lawrence River Basin.

Local fish consumption and serum PCB concentrations among Mohawk men at Akwesasne.

A study was conducted to assess local fish consumption patterns and their relationship to concentrations of total polychlorinated biphenyls (PCBs) in the serum of Mohawk men residing near three hazardous waste sites. From 1992 to 1995, 139 men were interviewed and donated a 20-ml venous blood sample. The results indicated that the men ate a mean of 21.2 local fish meals during the past year, compared with annual means of 27.7 meals 1-2 years before and 88.6 meals more than 2 years before (P<0.001 for test of trend). This change is probably a consequence of advisories issued against the consumption of local fish, since 97% of the men were aware of the advisories and two-thirds had changed their behavior as a result. Multiple regression analysis revealed that serum PCB levels increased with age (beta=0.036, P<0.001) and local fish consumption (beta=0.088, P=0.006). The data suggest that local fish consumption has contributed to body burdens in this population and that the advisories have been effective in modifying local fish consumption habits.

Maternal residential exposure to hazardous wastes and risk of central nervous system and musculoskeletal birth defects.

The authors used a case-control design to evaluate the risk of central nervous system and musculoskeletal birth defects relative to exposure to solvents, metal, and pesticide contaminants from hazardous waste sites. Cases included 473 central-nervous-system-defect births and 3305 musculoskeletal-defect births to residents of 18 counties in New York State; controls comprised 12,436 randomly chosen normal births. For each address at birth, the authors assigned a probability of exposure to solvents, metals, and pesticides from hazardous waste sites in the study area (n = 643). They also rated residences by proximity to air releases from industrial facilities and by contamination of community water supplies. Compared with individuals for whom a low probability of exposure existed, mothers who resided in areas assigned a medium or high probability of exposure to hazardous waste contaminants did not show an increased risk of either type of birth defects. After adjusting for mother's race and age, prenatal care initiation, and population density, the resulting relative risks were as follows: central nervous system defects and exposure to solvents, 0.8 (95% confidence interval [CI] = .4, .6); central nervous system and metals, 1.0 (95% CI = 0.7, 1.7); musculoskeletal defects and solvents, 0.9 (95% CI = 0.5, 1.3); and musculoskeletal defects and pesticides, .8 (95% CI = .5, 1.3). With respect to central nervous system defects, there was an elevated risk associated with living near industrial facilities that emitted solvents (odds ratio = 1.3 [95% CI = 1.0, 1.7]) or metals (OR = 1.4, [95% CI = 1.0, 1.8]) into the air. The low proportion of individuals who had a medium or high probability of residential exposure to hazardous waste-site contaminants limited the investigation of particular pathways, disease subgroups, and/or geographic areas. Associations between central nervous system defects and industrial releases of solvents and metals need to be investigated further.

Polychlorinated biphenyl (PCB) and dichlorodiphenyl dichloroethylene (DDE) exposure among Native American men from contaminated Great Lakes fish and wildlife.

The New York State Department of Health is performing an investigation of Mohawk men, women, and infants who live at the Akwesasne Reserve along the St. Lawrence River in New York, Ontario, and Quebec Three large industrial facilities bordering the Akwesasne Reserve have seriously contaminated the soil and the sediments and fish of the adjacent St. Lawrence River with polychlorinated biphenyls (PCBs). The main study goals are to investigate the associations among the consumption of locally caught fish, residential exposure, body burdens of PCBs, and liver enzyme induction. Contamination with PCBs, polychlorinated dibenzofurans, polychlorinated dibenzodioxins, polyaromatic hydrocarbons, dichlorodiphenyl dichloroethylene (DDE) and other chemicals has been documented in locally caught fish, ducks, and other wildlife. The contamination of fish and wildlife is a major concern of the Mohawk people, since their tradition and culture emphasize the interdependence of man and his environment and because many residents formerly depended heavily on local fish and waterfowl for food. The focus of this research from 1986-1992 was on nursing women and infants. The major purpose of the current project is to determine if there are associations between dietary, residential, and occupational exposures to PCBs and DDE and individual body burdens in Mohawk men, specifically the husbands, partners, fathers, brothers, or other male relatives of the women in our other studies. In other fish-eating populations, adult men have tended to demonstrate higher PCB and DDE body burdens than women and children. Exposure estimates based on the reported consumption of locally caught fish and wildlife and residential histories will be correlated with the specific pattern of PCB congeners found in serum, thereby establishing a direct relationship between two potential sources of exposure and body burdens. Liver function will be examined through the caffeine breath test (CBT), a sensitive, noninvasive method of assessment of enzyme induction, one of the earliest detectable biological responses to PCBs in laboratory animals. This test appears promising as a method to detect subtle subclinical effects before the onset of overt clinical symptoms. The project is among the first to explore differences in dietary and other exposures, body burdens, and potential adverse health effects due to specific PCB congeners in men and women from the same source population.