Tyler Chalfant | August 28, 2019
A child was poisoned earlier this summer in southern Iowa by a blue-green algae toxin that has been blamed for the deaths of six dogs across the country this summer. The algae, also called cyanobacteria, can cause rashes, nausea, vomiting, diarrhea, and in severe cases liver failure. It is especially dangerous for children and pets.
Overgrowth of this algae occurs in waters that are rich in nutrients. In Iowa, nitrogen and phosphorus pollution in water primarily comes from fertilizer runoff. Besides the harmful effects of their toxins, overgrowth of these algae can also impact other forms of life beneath the water’s surface by blocking sunlight and stealing oxygen and nutrients from other organisms.
The Iowa Department of Natural Resources tests state park beaches for microcystins, the toxic byproduct of blue-green algae, and issues swimming advisories if the water contains more than 20 micrograms per liter. However, this is less restrictive than the Environmental Protection Agency’s recommended standards of 8 micrograms per liter.
Cyanobacteria blooms often look like foam or floating paint near the water’s surface, though they can also hide beneath the water’s surface and may not be visible. When cyanobacteria die, they produce a bad smell, similar to rotting plants. The Center for Disease Control recommends that people avoid swimming and boating in water where algae appears or where water is discolored, and to rinse off as soon as possible if you are exposed to water that may contain cyanobacteria.