The Kentucky Division of Water and Kentucky Department for Public Health issued harmful algal bloom advisories for Briggs Lake in Logan County and along the Ohio River.
The state measured cyanotoxins at unsafe levels and warned against swimming, wading and “water activities that create spray” in Briggs Lake.
There was an algal bloom reported in Lake Malone in Logan, Mulhenberg and Todd counties, though the cyanotoxins were detected at levels below the advisory threshold at the time of sample collection, according to the Division of Water.
Algal blooms occur naturally with a combination of sunlight, warm weather, low-turbidity water and the presence of nutrients that phytoplankton thrive on – nitrogen or phosphorous.
But agricultural runoff, stormwater runoff, wastewater, fossil fuel use, fertilizers, detergents and pet waste contribute to nutrient pollution, which can cause harmful algal blooms, according to the Environmental Protection Agency.
Harmful algal blooms tend to pop up during hot, dry conditions, and the National Weather Service is on track to record Kentucky’s driest and second-hottest September on record – but the data is still being reviewed.
“Extreme heat and low flow promotes the development of algal blooms,” state climatologist Stuart Foster said.
Harmful algal blooms produce toxins called microcystins, which pose significant health risks to people, pets and wildlife. State officials said ingested water may increase the risk of gastrointestinal symptoms such as stomach pain, nausea, vomiting and diarrhea. It can also cause skin irritation.
If you are concerned that you have symptoms as a result of algal exposure, contact a health care provider.
Bloom conditions can change rapidly. To view current advisories, visit the state’s Hangul Algal Bloom viewer at watermaps.ky.gov/HABs.