Boaters’ Risk of Illness on Chicago River Similar to Other Waterways
[Writer] This is research news from U-I-C – the University of Illinois at Chicago. Today, Dr. Samuel Dorevitch, associate professor of environmental and occupational health sciences in the UIC School of Public, talks about the health effects associated with using the Chicago River for recreation.
Here’s professor Dorevitch:
[Dorevitch] For many years people thought of the Chicago River as just a sewer, basically, and it was not used for recreation. People stayed away from the Chicago River.
Over the last decade or so the Chicago River has been used more frequently. There are canoeing and kayaking clubs that use the river for practice, including for high school kids.
People fish on the Chicago River and over the years water quality has improved somewhat on the Chicago River because of better storm water management. The Illinois EPA which regulates water quality in the state considered expanding the types of recreational activities that are allowed to take place on the river and this might require changing wastewater management practices.
Right now, about three-quarters of the flow in the Chicago River is wastewater discharge from plants of the water reclamation district. The Metropolitan Water Reclamation District treats our wastewater and storm water but it isn’t disinfected with chlorine the way, say drinking water would be, or the way wastewater is handled in other cities. So hearings were held before the Illinois Pollution Control Board about what to do with
the Chicago River. The Illinois Environmental Protection Agency, the U.S. Environmental Protection Agency, and numerous environmental groups were advocating for having the wastewater disinfected before it leaves the Metropolitan Water Reclamation District treatment plants and goes into the river.
And in the middle of this process, the University of Illinois at Chicago was contacted by the Water Reclamation District looking for answers to public health questions that might help inform this regulatory proceeding.
The question that we were asked to address was ‘what are the health risks of water recreation on the Chicago River now?’ – meaning without disinfection. And in order to answer that question we designed a study that is called CHEERS, the Chicago Health, Environmental Exposure and Recreation Study, and the question that we tried to answer was ‘if a thousand people use the Chicago River for limited contact recreational activities, that means canoeing, kayaking, fishing, boating and rowing, how many would get sick? And of those how many would get sick because of use of the river?’ We would expect some people to get sick for unrelated reasons.
So we designed a study in which three groups of people were enrolled. These were people who used the Chicago River for those recreational activities that I mentioned, then we enrolled a group of people who did those same recreational activities on inland waters and then Lake Michigan.
We weren’t looking a people who swim, just people who do these same activities that happen on the Chicago River. And then we enrolled a third group of people who did outdoor recreation activities that don’t involve water. So on the same days at about the same places that we were enrolling people at the rivers and lakes we enrolled people who were jogging, rollerblading, playing softball, taking walks.
After enrolling study participants we followed them over time. We contacting them by phone three times over a three week period to determine did anybody get sick and if they did get sick, what type of symptoms did they have, how severe were the symptoms. And we were interested primarily in gastrointestinal illness but we also asked questions about eye symptoms and skin symptoms and ear symptoms and respiratory symptoms. This research took place in the summers of 2007, 2008 and 2009.
And now we have final results that show approximately 40 people per thousand get sick — develop gastrointestinal symptoms — that’s overall. But when we analyzed it trying to see what percent of people are getting sickness due to use of the river, in other words, comparing the people who are on the Chicago River to the other rivers or to the unexposed group, what we found is that about 14 people per thousand are getting sick due to water recreation.
And that was true whether it was water recreation on the Chicago River or water recreation on those other waters. And that was a bit of a surprise. I had expected that given that the Chicago River is primarily wastewater effluent I would have expected higher rates of sickness on the Chicago River than the other waters; but that was not the case.
Another finding is that people got eye symptoms more frequently if they used the Chicago River. That is more frequently than the group that was doing non-water recreation but also more frequently than people who did the same recreational activities on other area waters. That was about 14 per thousand on the Chicago River, compared to the other rivers and inland lakes. There’s about a 10 per thousand rate of eye symptoms that we saw among Chicago River users attributable to the Chicago River use. In other words, 10 people per thousand more than we were seeing on the other area waters, the inland lakes and rivers.
Another finding that was a bit surprising to me was that we didn’t observe very severe illness. We didn’t observe people who had used the Chicago River who then subsequently required hospitalization or emergency care at a high rate. That was at a very low rate and not different than the rates we saw among people who used other waters or the non-water outdoor enthusiasts.
The rates of illness for respiratory, skin and ear symptoms were the same for the Chicago River and the cleaner water groups.
One of the findings that could have some policy implications is that even among people who were doing limited contact recreation – canoeing, kayaking, fishing boating and rowing – on rivers that are not dominated by wastewater the fact that people were getting gastrointestinal illness at a rate of about 14 per thousand makes me think that if those people had been swimming the rate would have even been higher — that they would have been swallowing more water. So it does raise the question, not only is the Chicago River safe for use but what’s going on in these other waters and are there pollutants that we need to be getting a better handle on.
[Writer] Dr. Samuel Dorevitch is associate professor of environmental and occupational health sciences.
For more information about this research, go to www.today.uic.edu, click on “news releases.” … and look for the release dated October 26, 2011.
This has been research news from U-I-C – the University of Illinois at Chicago.
