Blue Green Water Algae Dangers

Blue-green algae include a number of photosynthetic bacteria species, known to scientists as cyanobacteria. They can be found on the surface of warm, slow or still lakes, ponds and wetlands and despite the name, range in color from olive-green to red. In hot, calm weather, the algae can multiply so rapidly they create a "bloom" on the water, which can pose a toxic threat to humans and other mammals.

Drinking the Bloom

• When cyanobacteria die, their cells rupture, releasing toxins into the water. Drinking water with large amounts of algae can cause serious illness, according to the New York State Health Department. Depending on the species of cyanobacteria, the toxins can do serious damage to the human liver or nervous system, as well as cause several days of fever, dizziness, cramps and vomiting.

Contact

• Swimming in a lake with an algal bloom or showering in water that contains algal toxins can irritate the skin and eyes, causing rashes and other problems. Close contact also increases the chance of inhaling the toxins, which can inflame the respiratory tract. If there's no visible bloom on a body of water, it's unlikely the toxins are strong enough to be a problem, but people who are particularly sensitive could still suffer symptoms.

Chronic Exposure

• Experiments on animals have shown that long-term exposure to cyanobacteria can also lead to liver damage, and possibly cause cancer, according to the World Health Organization. The WHO adds, however, that it's difficult to measure the precise health risk to people exposed to algal blooms outside the lab. Scientists are continuing research on the topic.

What To Do

• If you realize the water you've been washing with or swimming in contains an algal bloom, find a clean water supply and wash yourself thoroughly. Then contact your doctor. You should also call your doctor if you've been exposed to or swallowed bloom-water and develop any of the symptoms of cyanobacteria toxicity.