Arsenic levels in the soil and risk of birth defects: a population-based case-control study using GIS technology.

Arsenic is a highly dangerous metal that has been linked to a number of adverse health effects in both adults and children, including birth defects. Yet few epidemiologic studies have examined the relationship between arsenic levels in the soil and the risk of birth defects. The purpose of the authors' study was to examine this association among people exposed to environmental pollution in a developed area of China. The authors used global positioning system to locate the coordinates of 80 villages in 40 towns for soil sampling. Soil samples were analyzed for arsenic content. Logistic regression was used to investigate the relationship between exposure to arsenic and birth defects, controlling for potentially confounding factors. The authors found that exposure to arsenic in any amount increased the risk of birth defects. The positive association found between arsenic exposure and birth defects warrants further study, and future large-scale population-based studies are needed with an emphasis on individual-level exposure and confounding variables.