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Public health advisory issued for Henrys Lake in eastern Idaho

Located just west of Yellowstone National Park, Henrys Lake is a popular attraction for trout fishing. (Courtesy of Idaho Department of Health and Welfare)

The Idaho Department of Health and Welfare’s Division of Public Health has issued a health advisory for Henrys Lake in eastern Idaho after cyanobacteria was discovered in samples.

According to a press release from the Idaho Department of Health and Welfare, officials confirmed the presence of three species of cyanobacteria, which can produce toxins that can be harmful to people, pets and livestock.

Cyanobacteria occur naturally in Idaho’s waters, but when temperatures rise they can bloom and release toxic chemicals into the water. The blooms can vary in appearance but may look like foam, spilled paint or surface scum.

Located 15 miles west of Yellowstone National Park in Fremont County, Henrys Lake is a popular high mountain lake that attracts anglers fishing for cutthroat trout, hybrids and brook trout.

Public health officials urged people to avoid swimming, wading and other activities in the water at Henrys Lake and take extra precautions to ensure children and pets and livestock are not exposed to the water.

Public health officials also urged the public not to drink or cook using water from the lake, adding that boiling or filtering the water won’t remove the toxins and could increase the risks.

If people or animals are exposed to the water, skin and pet fur should be cleaned and washed immediately in clean water.

Symptoms of exposure to cyanobacteria can include diarrhea, vomiting, hives or rashes. People with liver or kidney damage are at an increased risk, public health officials said. If symptoms are severe or persist, people should call a doctor or healthcare provider.

Pets may become seriously sick or die within minutes of exposure to toxic cyanotoxins, Idaho Department of Health and Welfare officials said. Officials urged the public to contact a veterinarian immediately if pets or livestock appear sick after going in or drinking the water.

Idaho Department of Health and Welfare officials said they would issue a follow up announcement when the public health advisory is lifted.

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