Algae toxins in water supply worry health experts

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Algae toxins in water supply worry health experts

By Sargent Jr. | Sentinel Staff Writer

Posted October 23, 2002

ST. PETE BEACH -- Federal health officials expect to begin studies to find

Florida residents who suffered long-term illness from drinking tap water

laced with very small amounts of cancer-causing algae toxins.

A proposed project would focus on areas where residents most likely could be

exposed to toxins created by prolific varieties of algae taking over lakes

and rivers across the state.

And though no time has been set to begin work, researchers say it could be

an important step in gauging the danger of drinking from surface waters.

Studies from most of the state's 20 surface-water-treatment plants two years

ago showed that although rigorous cleanup methods could remove algae from

water, they often could not clean up toxins the algae released, according to

a report by the Florida Harmful Algae Bloom Task Force.

Two plants -- in West Palm Beach and near Sarasota -- tested higher than the

World Health Organization's safe level for microcystin, a tumor-promoting

toxin that has killed dozens of dialysis patients in Brazil.

Other facilities released toxins created by Cylindrospermopsis -- another

type of algae that creates a liver-damaging poison.

The question is:Can Florida's variety of these toxins have their own

dangerous effect on people here?

Biologists said they want to look for illnesses to know for sure.

" First is to attempt an exposure assessment, then we'll find out if the

exposure is important enough to proceed, " said Lorrie Backer, an

environmental-threat specialist the Centers for Disease Control and

Prevention.

Backer is among 700 top algae researchers meeting this week for XHAB 2002 --

the 10th International Conference on Harmful Algae in St. Pete Beach.

Many will present studies today about human health impacts of toxic algae

around the world.

Burns, director of the environmental research firm Cyanolab, said

several of Florida's surface-water plants now test for toxic algae following

the alarming reports.

However, researchers say most treatment efforts still cannot remove all

toxins from the water during heavy bloom periods.

The 2000 study tested for algae and their toxins at 15 of 20 water-treatment

plants that use surface water to serve more than 2 million people.

Most of Florida satisfies its growing thirst from ground water, which is

unlikely to have lots of toxic algae.

As the state's population continues to grow, more and more areas may depend

on lakes and rivers -- many that are loaded with algae -- to meet at least

part of increased demands.

" I think there is a real health issue here, " said Ian Falconer, an

Australian biologist with 25 years of experience studying freshwater

toxic-algae blooms, including some cases in Florida.

Wayne Carmichael, professor of aquatic biology/toxicology at State

University in Ohio, said that with opportunities for algae toxins to get

through treatment plants, there is concern to measure potential health

impacts.

" It's a logical question -- 'What is the human exposure?' " he said about

the need for health studies.

" That can be a daunting task. "

Sargent can be reached

at rsargent@...

or 352-742-5909.

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