Global Warming

Climate change drives spread of toxic algae in USA water supplies

Across the U.S., reservoirs that supply drinking water and lakes used for recreation are experiencing algae blooms which release toxins into the water with growing frequency. The trend represents another impact of global warming and raises looming questions about the effects on human health, researchers say.

Technically called cyanobacteria, the ancient class of organisms that create the blooms are present nearly everywhere water is found but thrive in warm, still bodies like lakes and ponds. They also create a unique class of toxins, the impact of which on humans is only partly understood.

Long linked to animal deaths, high doses of the toxins in humans can cause liver damage and attack the nervous system. In the largest outbreaks, hundreds have been sickened by blooms in reservoirs and lakes, and officials in some areas now routinely close water bodies used for recreation and post warnings when blooms occur.

In Lake Erie, a major bloom in 2014 caused authorities to warn against drinking tap water in Toledo, Ohio, for more than two days, cutting off the main water source for more than 400,000 people. Now blooms happen every year in Utah and Ohio. Other blooms, including flare-ups affecting drinking water, have been logged in recent years in New York, Florida and California. In Oregon, officials lifted Salem’s drinking water advisory after several days, but then had to reissue the warning. Testing for the blooms isn’t required by either federal or state law.