Hydrogeologic assessment of exposure to solvent-contaminated drinking water: pregnancy outcomes in relation to exposure

Observed clusters of miscarriages and birth defects often lead to speculation about presumed environmental causes. In the early 1980s in the Los Paseos area of Santa Clara County, California, the relation between an alleged cluster of such adverse pregnancy outcomes and a leak of trichloroethane from a factory storage tank into a single well was proposed. Several preliminary studies suggested that the cluster in the exposed area was statistically significant when compared with pregnancy outcomes in an unexposed area. However, available information about the extent and timing of the exposure was inadequate to support or deny a cause and effect relationship between the two events. A further study was performed to estimate the probable exposure of individuals in two areas adjacent to the trichloroethane-contaminated water and to analyze pregnancy outcomes in relation to exposure. The results do not support the notion that exposure to drinking water contaminated by a tank leak caused or was related to a higher incidence of miscarriages and birth defects. In fact, one of the two areas studied had lower rates of miscarriage, but higher estimated exposure to trichloroethane and the contaminated well. Similarly, of six live births with reportable malformations, there was less average exposure to trichloroethane and lower probability of exposure to contaminated water than in normal infants from the same area. Other environmental or infectious causes may have been involved in this cluster of adverse pregnancy outcomes, but the cause may never be known. There is also a possibility that the observed cluster may be due to chance occurrence. A future report will discuss this possibility. (Consumer Summary produced by Reliance Medical Information, Inc.)
Hydrogeologic Assessment of Exposure to Solvent-Contaminated Drinking Water: Pregnancy Outcomes in Relation to Exposure THE CALIFORNIA DEPARTMENT of Health Services has conducted several studies to investigate community concerns that an [...]