The comparable risk levels may be "because people are more likely to capsize in cleaner waters and ingest more water than they do at the Chicago River, where people are generally aware of water quality problems on the river and are careful not to fall in the water or to swallow water," he said.
"The fact that 14 people per thousand, instead of eight per thousand, on average, are getting sick due to their use of the water is concerning," Dorevitch said. "It means that we may have a higher rate of illness at inland waters than would be acceptable at coastal waters. This raises the question, should the EPA be doing more to protect people in those inland waters?"
The CHEERS study did not track illness rates among swimmers at beaches.
The researchers enrolled more than 11,000 people in the study. One group used the Chicago River system for recreational activities, another group did the same recreational activities on waters approved for swimming, and a third group participated in non-water recreational activities such as jogging, cycling, or walking. The study was conducted in the summers of 2007, 2008 and 2009.
The water recreation participants were interviewed before and immediately after activities on the water. They were followed over three weeks to see if they developed gastrointestinal, skin, eye, ear or respiratory conditions.
Users of the Chicago River system -- which receives wastewater from treatment plants that use an activated sludge process, but no disinfectant such as chlorination -- did not have gastrointestinal illnesses more severe than that experienced by users of waterways where swimming is permitted -- a f
|Contact: Sherri McGinnis Gonzlez|
University of Illinois at Chicago