November 7, 1997

Blue green danger

Dr. Charles Holmes

Heritage researcher Dr. Charles Holmes can often be found on a hot summer's day on the shores of one of Alberta lakes. But he's not sunbathing. Holmes is usually wading knee-deep into foul-smelling blankets of blue-green algae on the water's surface, filling endless buckets with the slime to test in his U of A lab.

Blue-green algae blooms are on the rise worldwide, possibly because of increased use of fertilizers in farming. The chemicals in agricultural runoff provide increased nutrification in the water, promoting more frequent and more extensive algae blooms. While not all algae contain toxins, more algae growth means greater potential for harmful microcystin contamination.

Microcystin toxin can be lethal to animals and humans when taken directly into the bloodstream. It is as potent as cobra venom, and an amount the weight of a few grains of sand could kill an adult human if injected. Yet, blue-green algae has been used as a food supplement for centuries, without any documented ill effects. This could be because stomach acids would destroy any microcystins. However, there is a growing amount of evidence from biochemical research like that of Holmes' to suggest swallowing blue-green algae has a number of effects.

"The boost of energy some people get when they eat blue-green algae results from a reaction in the liver. Microcystins alter how the liver breaks down glycogen, a complex carbohydrate. The result is similar to a rush of adrenaline. The use of blue-green algae for race horses is because of this energy boost, yet it's not a banned substance like other stimulants," says Holmes. "However, because microcystins are very strongly linked to liver cancer, we can't be sure the digestive system destroys all the toxin."

"It's difficult for consumers to tell if blue-green algae food supplements contain microcystins, because the health food industry is unregulated, so the testing that would indicate their presence is not mandatory," he adds. Testing by his U of A biochemistry students last year as a lab project revealed microcystins in several types of algae food supplements.

Health Canada strictly enforces testing for drinking water, however. The Manitoba government for the past three years has contracted Holmes' lab to test Winnipeg's drinking water source, which regularly experiences algae blooms. When blooms occur, Winnipeg switches water sources until the bloom is finished. In Alberta, the story is different.

When several Alberta lakes experience algae blooms with microcystins present, water filtration systems cannot remove all of the toxin. This isn't normally a problem because the microcystin levels to date have been within Health Canada guidelines, and the water is used for drinking.

It's when water is used for kidney dialysis treatments and comes in close contact with the patient's bloodstream-that safety issues arise. Holmes tests the water used for dialysis in Northern Alberta, and says, "In Canada, sophisticated filtration systems that employ correctly functioning reverse osmosis equipment provide a high degree of assurance that kidney dialysis water is safe, but in many countries of the world, such standards are difficult to maintain.

In Brazil last year, 50 kidney dialysis patients died because of microcystins in the treatment water."

Holmes has developed a technology that can help prevent such tragedies. His kit, which is being developed for commercialization, could realize a global market potential because it's easy to manufacture and, since it's based on a color change, it is easy to use.

Holmes' research and resulting innovation shows that Albertans aren't completely out of the water when it comes to contaminated algae blooms, but with vigilant testing and excellent science, we can maintain the highest levels of safety for vulnerable populations.

Holmes is a Heritage Senior Scholar at the University of Alberta's Department of Biochemistry. He also receives support from MRC Canada.

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