AP News, July 12th, 2007
Tests that determine whether toxic chemicals accumulate in food may be missing some hazardous materials and need to be updated, a Canadian researcher said Thursday.
It has long been known that toxins can accumulate in the food chain, rising to higher concentrations as larger animals eat smaller ones.
But current tests for this accumulation focus on foods of aquatic origin, Frank A. P. C. Gobas, an environmental chemist and toxicologist at Simon Fraser University in British Columbia said in a telephone interview.
Researchers have found there are chemicals that do not accumulate in fish, but which do so in air-breathing animals, such as mammals, Gobas reports in a paper in Friday's issue of the journal Science.
Bioaccumulation testing is done in the same way in most countries, Gobas said: "We're all basically making roughly the same mistake."
He said testing must be updated to cover chemicals that do not accumulate in marine life but may do so in air-breathing animals because of their slow rate of elimination during respiration.
Gobas said he has been studying the food chain of animals in the Canadian arctic where caribou eat lichen and wolves eat caribou. He said he found increasing accumulations of potentially toxic chemicals moving up that food chain, though the same chemicals did not accumulate in marine life. Further study found the same in other animals.
Was he surprised?
"Well, you're always surprised, of course, but in hindsight I should not have been. It made us think about the process in a different way," he said.
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