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Joseph L. Jacobson, Ph.D. Background: Indigenous people living in Nunavik, a region of Northern Quebec, Canada, consume large amounts of marine foods and are therefore exposed to high levels of biopersistent and bioaccumulating food chain contaminants. This research study measured persistent organic pollutants, mercury, and lead in umbilical cord blood samples from infants from three communities on the east coast of Hudson Bay in Nunavik. The researchers analyzed 251 samples collected from 1994 through 2001 for polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane (DDT), dichlorodiphenyl dichloroethylene (DDE), hexachlorobenzene (HCB), chlordanes, lead and mercury. All of these compounds are known to have adverse health outcomes. Advance: The investigators found significantly decreasing trends for PCBs, DDT, DDE, and HCB ranging from 6.6% to 9.1% per year. No significant trend was noted for chlordane. Lead and mercury each declined by approximately 50% during the period of sample collection; however, there was no clear linear trend. Implication: Since the 1970s, many restrictions and regulations have helped drastically reduce the input of persistent organic chemicals and heavy metals in the environment, and exposure through food contamination decreased accordingly. In this study, the investigators attribute the decline mainly to a diminution of food contamination and, to a lesser extent, dietary changes. Although questions remain as to the exact causes of the decline, it is encouraging to observe such an improvement in prenatal exposure for this highly exposed population. These researchers suggest that international efforts to further reduce environmental contamination should be continued. Citation: Dallaire F, Dewailly E, Muckle G, Ayotte P. Time trends of persistent organic pollutants and heavy metals in umbilical cord blood of Inuit infants born in Nunavik (Quebec, Canada) between 1994 and 2001. Environ Health Perspect. 2003 Oct; 111(13):1660-4. |
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