Toxic algae found in small amounts in Lake Mead

Thursday, Dec. 4, 2003 | 9:40 a.m.

Southern Nevada water officials have formed a task force to track a blue-green algae in Lake Mead because the algae can be toxic in high concentrations.

Trace amounts of the poison were discovered in the lake over the summer. The algae, cylindrospermosis, was detected by the Nevada Division of Environmental Protection and the Southern Nevada Water Authority during routine testing of lake water in August.

One of three toxins produced by the algae was at 0.054 micrograms per liter of water, said Jason Kuchnicki, a state environmental agency official.

That amount is too weak to affect people's health, Kuchnicki said. Australian scientists have reported that up to 1 microgram per liter is safe and possibly the toxin is not dangerous to humans until there are more than 15 micrograms of the toxin per liter of water.

Southern Nevada's water supply includes water from the lake but there's no risk of ingesting the toxin because ozonation treatment used on the water drawn from Lake Mead kills the algae, a Water Authority spokesman said.

The algae is common in lakes around the world, including the Great Lakes and those in Florida. It thrives in warm water.

Next summer when Lake Mead warms up again, state and local water scientists will be ready for the algae bloom, Kuchnicki said.

The algae task force will test the water for the algae every two weeks from July through October, he said. The current testing schedule is only once a month, he said.

The task force also is preparing a fact sheet about the blue-green algae for the public.

In case toxins are found in the future, a warning will be circulated to lake users to explain how to avoid the poison, Kuchnicki said.

In September 2004 scientists plan to sample a stretch of the Colorado River from Colorado to Arizona to check for the organism.

Blue-green algae are tiny, simple plants that live in fresh or salt water, even dam areas, around the world, according to the North Carolina Public Health Department website.

No human deaths from blue-green algae's toxins have been reported in the United States, but in 1996, in a kidney dialysis clinic in Brazil, 126 patients became ill and 60 died after untreated water heavily contaminated with blue-green algae was used for dialysis during a water shortage.