Health Effects of Harmful algal blooms
Who is at risk of exposure?
People and pets can be exposed to toxins from harmful algal blooms by skin contacting water
containing toxins while swimming or doing other activities in the water, drinking water containing toxins,
breathing in tiny droplets in the air that contain toxins, and eating fish or shellfish that contain toxins (CDC 2021). Knowing the signs of harmful algal blooms and symptoms that may appear after exposure can help keep you and your family safe. Visit the What page to learn what harmful algal blooms can look like.
People, pets and livestock should avoid contact with any floating mats, scums, or discolored water. Colors can include shades of green, blue-green, yellow, brown or red. Never drink, prepare food, cook, or make ice with untreated surface water, whether or not algae blooms are present. In addition to toxins, untreated surface water may contain bacteria, parasites, or viruses that could cause illness if consumed. People not on public water supplies should not drink surface water during an algal bloom, even if it is treated, because in-home treatments such as boiling, disinfecting water with chlorine or ultraviolet (UV), and water filtration units do not protect people from HABs toxins (DEC).
