Effect of climate changes on waterborne disease in The Netherlands.

Effects of climate change in The Netherlands in the 21st century on the microbiological quality of water for drinking water production and recreation were evaluated. The following was concluded: increased temperature leads to significant additional inactivation of enteric pathogens in surface waters with residence times of more than a month, but not in waters with residence times of up to ten days. Increased precipitation, runoff and storm water overflow lead to more peak concentrations of waterborne pathogens in surface water. Peak concentrations strongly determine the infection risk through drinking water consumption. Drought lowers and increased precipitation elevates groundwater tables, but an effect on the risk of groundwater contamination with waterborne pathogens is not clear. Climate effects are not noticeable near a groundwater well, where the groundwater table and flow rate are mainly determined by the pumping rate. Exposure of recreants to waterborne pathogens that can grow in the water is expected to increase due to increased recreation and increased growth opportunities of these pathogens. Due to warmer summers, pathogens, like amoeba, that have not caused problems up to date in The Netherlands, may now emerge in recreational waters.