Follow-up samples collected in the Illinois River last week showed no evidence of the algal toxin, microcystin, including samples collected near Hennepin and Marseilles (m-ar-say). Previous samples collected at these locations detected microcystins above the 4 parts per billion (ppb) draft health advisory established by U.S. EPA. It is likely that heavy rains received in northern Illinois contributed to the improved conditions in the river.
Illinois residents should continue to use caution while recreating in, on, or near Illinois rivers, lakes or streams and be advised to avoid contact with water that:
• looks like spilled, green or blue-green paint
• has surface scums, mats, or films
• is discolored or has green-colored streaks, or
• has greenish globs suspended in the water below the surface.
Do not let pets drink from water with any of the above characteristics.
Algal toxins sometimes produced by blue-green algae can cause sickness or other adverse health effects in people and pets, depending on the amount and type of exposure. The very young, elderly, and people with compromised immune systems are most at risk. Adverse health effects attributable to algal toxins can occur from direct skin contact, swallowing contaminated water, or inhaling water droplets in the air. Symptoms of exposure include rashes, hives, diarrhea, vomiting, coughing or wheezing. More severe symptoms may result from longer or greater amounts of exposure.
For additional information about harmful algal blooms visit www.dph.illinois.gov.