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Dioxins and Cardiovascular Mortality: A Review (EHP)
Citation:
Humblet, O., L. S. BIRNBAUM, M. A. mittleman, AND R. HAUSER. Dioxins and Cardiovascular Mortality: A Review (EHP). ENVIRONMENTAL HEALTH PERSPECTIVES. National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, 116(11):1443-1448, (2008).
Impact/Purpose:
There have been many studies looking at the effects of dioxin in people. However, relatively few have examined heart disease in a population with a validated exposure metric. This paper shows a clear exposure-related association between dioxin and cardiovascular disease in people. The agency is finally completing its long term reassessment of the health risks of dioxin and this paper will help in this final evaluation.
Description:
In spite of its large public health burden, the risk factors for cardiovascular disease remain incompletely understood. Here we review the association of cardiovascular disease (CVD) mortality with exposure to dioxin, a pollutant resulting from the production and combustion of chlorinated compounds. This complements a large body of dioxin epidemiology research that until now has focused primarily on carcinogenicity. We also briefly review the substantial evidence for dioxin cardiotoxicity in animals. OBJECTIVE: In this systematic review we evaluated the evidence on the association between dioxin exposure and cardiovascular disease (CVD) mortality in humans. DATA SOURCES AND EXTRACTION: We conducted a PubMed search in December 2007 and considered all English-language epidemiologic studies and their citations regarding dioxin exposure and CVD mortality. To focus on dioxins, we excluded cohorts that were either primarily exposed to polychlorinated biphenyls or from the leather and perfume industries, which include other cardiotoxic coexposures. DATA SYNTHESIS: We included results from 12 cohorts in the review. Ten cohorts were occupationally exposed. We divided analyses according to two well-recognized criteria of epidemiologic study quality: the accuracy of the exposure assessment, and whether the exposed population was compared with an internal or an external (e.g., general population) reference group. Analyses using internal comparisons with accurate exposure assessments are the highest quality because they minimize both exposure misclassification and confounding due to workers being healthier than the general population ("healthy worker effect"). The studies in the highest-quality group found consistent and significant dose-related increases in ischemic heart disease (IHD) mortality and more modest associations with all-CVD mortality. Their primary limitation was a lack of adjustment for potential confounding by the major risk factors for CVD. CONCLUSIONS: The results of this systematic review suggest that dioxin exposure is associated with mortality from both IHD and all CVD, although more strongly with the former. However, it is not possible to determine the potential bias, if any, from confounding by other risk factors for CVD.