Climate and waterborne disease outbreaks

Regional climate change and variability and their effect on water resources have not been the subject of much study. Climate predictions suggest that storms will be of greater intensity and that the average precipitation even t is likely to be heavier. Rainfall and runoff have been associated with in dividual outbreaks of waterborne disease caused by fecal-oral pathogens. Wa terborne disease outbreak data from 1971 through 1994 were analyzed for gro undwater and surface water in 2,105 US watersheds. Between 20 and 40 percen t of outbreaks were associated with extreme precipitation. This relationshi p with extreme precipitation was found to be statistically significant for both surface water and groundwater, although it was more apparent with surf ace water outbreaks. The authors offer recommendations for improving the as sessment of changes in water quality and the effect that climate variabilit y and environmental factors have on waterborne disease risk.