An SFU biologist is urging Health Canada to toughen its shellfish consumption guidelines after finding what she believes to be dangerous concentrations of a potentially hazardous substance in B.C. seafood.

Leah Bendell says concentrations of cadmium, a toxic metal, in oysters, scallops and mussels harvested in coastal B.C. can be two to 10 times higher than elsewhere in the world.

Bendell hopes her findings, which were quoted this month in the Environmental Health Perspectives journal, will motivate Health Canada and the B.C. Centre for Disease Control to toughen their stances on shellfish consumption guidelines.

"Consumers need to know exactly how much shellfish they can safely eat to ensure that long-term exposure to cadmium doesn't jeopardize their health," Bendell said.

On its website, the Canadian Food Inspection Agency warns consumers of elevated cadmium levels in B.C. oysters and whole scallops.

Although cadmium is a naturally occurring element found in the environment, the CFIA says chronic exposure over a long period of time could lead to kidney damage.

In a statement emailed to CTV News, Health Canada said its own 2002 testing found cadmium levels in B.C. oysters were higher than in some other products.

The agency recommends adults should limit oyster consumption to 460 grams, or 12 oysters, a month. Children should only consume 1.5 a month.

Health Canada said it is currently reviewing the latest science on cadmium toxicity in B.C. shellfish.

"Once that assessment is completed, we will be reviewing the existing consumption advice to determine if any changes are warranted," spokesperson Stéphane Shank wrote.

Health Canada describes cadmium as a heavy metal "known to be more toxic than lead" and "a known carcinogen" in a webpage updated in October.

Bendell says Health Canada's information is inadequate and incorrect because it doesn't acknowledge what she believes is a proven link between cadmium exposure and disease.

"There's no reference to high risk groups, such as indigenous people, who are often already pre-disposed to cadmium-related diseases such as diabetes and cancer," she said.

Guy Dean, Vice-President of Albion Fisheries in Vancouver, says the seafood industry has always been aware of elevated levels of cadmium in shellfish, but they are within CFIA and Health Canada guidelines.

"They've deemed there is no health risk," he said.

Dean says the B.C. seafood industry has been restricted from exporting its products to places that don't allow any cadmium in their seafood, like Hong Kong.

"They want zero tolerance in cadmium into their marketplace so we have been restricted in where we send our product," he said.

In Europe, health agencies recommend people only consume one oyster a week. Guidelines set by the United Nations and the World Health Organization consider three a week to be within a safe consumption level.