Officials with the Iowa Department of Natural Resources (DNR) say unseasonably warm weather and water temperatures have prompted concerns about microcystin, a product of blue-green algae. There are currently advisories for total microcystins for the beaches on Big Creek Lake near Saylorville, Green Valley Lake north of Creston, and Rock Creek Lake near Kellogg.  Blue-green algae can grow quickly and become very abundant in warm, shallow, undisturbed surface water that receives a lot of sunlight – conditions that have been prevalent throughout the state this summer. Because the conditions are conducive to blue-green algae growth, people and pets should not be in contact with water that has a poor appearance.

The appearance can be a pea-green or blue-green color, but also a reddish-brown. It may appear with scum, foam or as a thick mat on the water surface. Blue-green algae can grow quickly and become very abundant in warm, shallow, undisturbed surface water that receives a lot of sunlight. The main risk to humans from microcystin is skin irritations and rashes, but if the water is swallowed or airborne droplets are inhaled during swimming, bathing or showering, symptoms could be worse. Those would include headaches, nausea, abdominal pain, seizures, liver injury and respiratory problems.

Precautions that should be taken to prevent health-related problems due to harmful algal blooms include:  Don’t swim, water ski or boat in areas where the water is discolored or if there is foam, scum or mats of algae on the water;  If you come in contact with water that might have a harmful algal bloom, rinse off with fresh water as soon as possible; Don’t let pets or livestock swim in or drink from areas where water is discolored, of if there is foam, scum or mats of algae on the water; Don’t let pets (especially dogs) lick the algae off their fur after swimming in scummy water; Don’t irrigate lawns or golf courses with pond water that looks scummy or has a bad odor; Don’t drink the water. Boiling the water will not make it safe to drink.