SPRINGFIELD – The Illinois Environmental Protection Agency and Department of Public Health are advising residents to use caution while recreating in Illinois lakes and rivers. This summer, individuals should be aware and watch for blue-green algae blooms beginning to form on lakes and ponds across the state. Blue-green algae (also known as cyanobacteria) are microscopic organisms that naturally occur in lakes and streams. Rapid growth of algae is referred to as a “bloom.”
With the upcoming Memorial Day weekend, Illinois officials are reminding residents to be cautious if they are planning activities on Illinois lakes and rivers now and throughout the summer. Some blue-green algae produce toxic chemicals that cause sickness or other adverse health effects in people and pets depending on the amount and type of exposure. The very young, the 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 to algal toxins include rashes, hives, diarrhea, vomiting, coughing, or wheezing. More-severe symptoms may result from longer or greater amounts of exposure.
People who plan to recreate in or on Illinois lakes or rivers this summer, and their pets, are 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
• has greenish globs suspended in the water below the surface
If you or your pet comes into contact with water you suspect may have a bloom of blue-green algae, rinse off with clean, fresh water as soon as possible. Likewise, if you plan to eat fish you catch from water that has a bloom of blue-green algae, rinse all fish parts well in tap water before cooking and eating. Activities near, but not in or on a lake or river, such as camping, picnicking, biking, and hiking are not affected. With all activities, wash your hands before eating if you have had contact with lake water or shore debris.
If you are concerned you have symptoms that are a result of exposure to algal toxins, contact your health care provider or call the Illinois Poison Center at 1-800-222-1222. If your pet experiences symptoms that may be a result of exposure, contact your veterinarian.
For additional information about harmful algal blooms, please visit