A study out in the journal Epidemiology and Infection reports that Canadians who receive water from household or private wells may be at a greater risk of contracting waterborne illnesses than those served by municipal systems. Private household wells are not regulated in Canada or the United States.
Each year, more than 20 million people in Canada report some level of acute gastrointestinal illness (AGI). Though much is known about AGI in relation to food, little is known about the connection between AGI and drinking water.
The study’s first author, assistant professor of environmental health, Heather Murphy, developed an estimate to understand the risk of waterborne illness caused by five key pathogens - Giardia, Cryptosporidium, Campylobacter, E. coli 0157 and norovirus in private groundwater supplies in Canada. Private water wells and small community systems provide water to 12 percent of Canada or four million people.
According to Murphy, this study has potential implications for Pennsylvania and other states that rely on groundwater. Pennsylvania has the second highest number of wells in the United States, which provide drinking water to three million people. (Michigan has the most wells.)
Murphy and researchers from Public Health Agency of Canada and Health Canada created a Quantitative Microbial Risk Assessment (QMRA) to estimate the number of AGI cases that could be related to the five identified pathogens. “The number of cases of AGI attributable to private wells in Canada is 78,073 and could be as many as 81,000 annually in Pennsylvania if we apply the same approach,” said Murphy.
Murphy conducted this research while a research fellow at the Public Health Agency of Canada. In a separate study, Murphy and the research team looked at waterborne disease burden associated with municipal drinking water systems.