The Indiana State Department of Health has been notified of an increase of blue-green algae at Geist and Morse Reservoirs in addition to an elevated level of microcystin (an algal toxin) at Geist.
Working collaboratively with the Hamilton and Marion County Health Departments, state health officials want Hoosiers to be aware and use caution when swimming, skiing, or participating in other recreational activities in either reservoir.
“It is important for individuals to avoid coming into direct contact with the algae and try to avoid swallowing water if at all possible,” said James Howell, DVM, State Epidemiologist.
While there are no U.S. standards regulating algal cell counts, the World Health Organization designates risk categories for recreational contact with water. Low risk levels, approximately 2-4 parts per billion (ppb), have been observed at Geist Reservoir in the past, but current data shows nearly 6 ppb of microcystin in Geist Reservoir.
If present, standard water treatments prevent algal toxins from affecting drinking water, but it may adversely impact recreational users of the reservoir, like swimmers, tubers, and jet skiers who have skin contact or may swallow large amounts of untreated water.
Direct contact with blue-green algae can cause skin irritation. Drinking untreated water, intentional or accidental, may result in gastrointestinal illness and more severe illness may occur with the presence of microcystin toxin.
Dr. Howell says it is always a good idea to take a bath or shower with warm, soapy water after coming in contact with untreated water in ponds and lakes, especially before preparing or consuming food. He also recommends people never drink, cook, or shower with untreated water from lakes, ponds, or streams. Pets and livestock should also not be allowed to swim in or drink untreated water from these sources.
For more information on blue-green algae, visit Indiana’s Blue-Green Algae Web site at www.algae.IN.gov. The Web site is a collaborative effort of the Indiana Department of Natural Resources, the Indiana Department of Environmental Management, the Indiana State Department of Health, and the Indiana Board of Animal Health, in cooperation with the Center for Earth and Environmental Science at Indiana University-Purdue University Indianapolis.
