Investigation of potential health effects associated with well water chemical contamination in Londonderry Township, Pennsylvania, U.S.A.

A community health survey was conducted by the Pennsylvania Department of Health in Londonderry Township, Dauphin County, Pennsylvania, in response to concerns about potential health effects associated with residential exposure to chemical contaminants in well water. The data indicate that there were no observable adverse health effects in the exposed group of residents, compared with the control group, which could be ascribed to long-term, low-level exposure to trichloroethylene (TCE) and other volatile organic chemicals. Significantly more individuals in the exposed group than in the control group experienced eye irritation, diarrhea, and sleepiness during the 12-month period prior to the survey. This indicated the possibility of an association of contaminated water with the manifestation of symptoms. It is hypothesized that the increased rate of symptoms observed in the exposed group, when compared to the control group, may have been caused by one or more of the following factors: (1) effect of TCE at a threshold level higher than 28 ppb, (2) effect of a single chemical entity other than TCE, and (3) additive or synergistic effects of several chemicals. It is also possible that there are factors other than water contaminants associated with the recorded symptoms, e.g., stress, that may have had an important influence in the exposed group but not in the control group.