SPH Study Shows Water Quality Linked to Increase in Hospital Visits

In the first study to examine the impact of water quality on children's health, School of Public Health investigators estimate there is a 10 percent increase in gastrointestinal emergency visits for children ages 3 and older within four days following a significant increase in water turbidity (cloudiness). Hospital admissions increased even more. The study is published in the November Epidemiology.

Danger signs about U.S. water quality have largely gone unheeded. The 1993 outbreak of cryptosporidiosis in Milwaukee that made 400,000 people ill and caused more than 100 deaths occurred in a water supply that was both disinfected and filtered. While outbreaks have been investigated, no one has questioned whether drinking water quality on a day-to-day basis is related to hospital visits.

Turbidity, a measure of "cloudiness" of the water, is often used as a proxy measure of the risk of microbial contamination and the effectiveness of public drinking water treatment. "We were interested in how well turbidity serves to indicate the microbiological integrity of the water even after chlorination and filtration efforts," comments Joel Schwartz, associate professor of environmental epidemiology at the School of Public Health. "To do so, we compared fluctuations in turbidity to daily hospital use for gastrointestinal diseases in Philadelphia. Our findings suggest that chlorine and filtration practices may not be the whole answer to ensuring water quality."

When turbidity changed from the lowest quartile to the highest quartile, it was found that hospital admissions of children increased by over 10 percent. Emergency room visits also increased. This pattern was seen during a period when all Environmental Protection Agency water quality standards were being met, noted Schwartz.