Fetal Deaths and Proximity to Hazardous Waste Sites in Washington State

Article excerpt

BACKGROUND: The in utero period is one of increased susceptibility to environmental effects. The effects of prenatal exposure to environmental toxicants on various adverse pregnancy outcomes, including fetal death, are not well understood.

OBJECTIVE: We examined the risk of fetal death in relation to maternal residential proximity to hazardous waste sites.

METHODS: We conducted a population-based case--control study using Washington State vital records for 1987-2001. Cases were women with fetal deaths at [greater than or equal to] 20 weeks (n = 7,054). Ten controls per case were randomly selected from live births. Locations of 939 hazardous waste sites were identified from the Department of Ecology registry. We measured distance from maternal residence at delivery to the nearest hazardous waste site, and calculated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS: The risk of fetal death for women residing [less than or equal to] 0.5 miles, relative to > 5 miles, from a hazardous waste site was not increased (adjusted OR = 1.06; 95% CI, 0.90-1.25). No associations were observed for any proximity categories [less than or equal to] 5 miles from sites with contaminated air, soil, water, solvents, or metals; however, fetal death risk increased among women residing [less than or equal to] 1 mile from pesticide-containing sites (OR = 1.28; 95% CI, 1.13-1.46).

CONCLUSION: These results do not suggest that fetal death is associated with residential proximity to hazardous waste sites overall; however, close proximity to pesticide-containing sites may increase the risk of fetal death.

KEY WORDS: birth certificates, environmental exposures, fetal death, fetal death certificates, pesticides. Environ Health Perspect 115:776-780 (2007). doi:10.1289/ehp.9750 available via http://dx.doi.org/ [Online 14 February 2007]

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More than 6 billion tons of waste are produced annually in the United States and are stored at more than 15,000 hazardous waste sites (National Resource Council on Environmental Epidemiology 1991). Most of these are waste-storage or treatment sites such as landfills or sites formerly used by industries (Landrigan et al. 1999). To address the health hazards associated with exposure to the contents of these sites, in 1980, the U.S. Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act, more commonly referred to as the Superfund Act [National Resource Council on Environmental Epidemiology 1991; U.S. Environmental Protection Agency (EPA) 2006b]. The act was amended in 1986 to provide additional funds, emphasize permanent remediation, increase state involvement, and improve efforts to deal with human health problems associated with proximity to these sites. The National Research Council Committee on Environmental Epidemiology (1991) reported that in 1991, 40 million people lived within 4 miles of a Superfund site.

One of the concerns about living near hazardous waste sites is the effect it may have on fetal development. The in utero period is one of increased susceptibility to environmental effects, and some studies have suggested that prenatal exposure to environmental toxicants may result in spontaneous abortion, malformations, or low birth weight (Carpenter 1994; Landrigan et al. 1999). Results of some other studies, however, have not been consistent with these observations (Baker et al. 1988; Croen et al. 1997; Fielder et al. 2000; Kharrazi et al. 1997; Sosniak et al. 1994).

Reducing the mortality ratio (the number of fetal deaths per 1,000 live births) among fetuses of [greater than or equal to] 20 weeks gestation to 4.1 deaths per 1,000 live births has been identified as a national public health priority by the U.S. Department of Health and Human Services (2000). In 2003, the fetal mortality ratio in Washington State was 6.2 (Washington State Department of Health, Center for Health Statistics 2006). …