Two U.S. environmental groups have filed notice they plan to sue several fish producers -- including three B.C. companies -- under a California anti-toxics law.

The move comes in the wake of a scientific journal's report published two weeks ago, which found that farmed salmon around the world contain far higher levels of cancer-causing chemicals known as PCBs.

The problem, as described in the article in Science, is the toxins concentrated in the fish feed.

Eating one meal per month could raise one's cancer risk later in life and possible hurt fetal development in the womb.

Canadian farm-raised salmon was found to be among the safest, but the researchers recommended only half a meal of it per month.

Government officials say eating farm-raised salmon is safe, as does the industry.

The concerns raised by the report, however, were enough to trigger the suit.

"We believe it's the responsibility of these companies to ensure that the fish they sell is not contaminated with toxic chemicals," Michael Green, executive director for the Oakland-based Center for Environmental Health, told The Associated Press.

"It's a simple matter of changing what they feed, what they feed the fish," he told CTV.

In fact, Green's and the other groups behind the suit told CTV they would be satisfied if the suit never made it to court if the industry did change its feeding practices.

The lawsuit comes at an already bad time for the farmed salmon industry, which has been seen demand for its product decline since the study was released.

"I couldn't find a piece of farmed salmon anywhere in the market across the street here," said Robert Clark, chef at C Restaurant on the waterfront of Vancouver's False Creek. "A lot of paranoia set in."

"Any time you see alarming headlines and you see people telling consumers to stop eating salmon, that's a cause for concern," said Mary Ellen Walling, executive director of the B.C. Salmon Farmers Association.

B.C. salmon farmers do test for unacceptable levels of PCBs, she said.

Salmon farming has grown into a big industry in B.C. It employs about 4,000 people and pumps $600 million into the province's economy.

About 85 per cent of its product is exported, mostly to the U.S. market.

Her group has tried touting the health benefits of salmon, such as the heart benefits from the Omega-3 fatty acids it contains.

But in fish markets and restaurants alike, vendors are trying to push wild salmon, which has reduced levels of PCBs. Those working at fish markets say they've noticed a downturn in the amount of farmed salmon sold.

Farmed salmon is much cheaper than wild salmon, so one could conclude some consumers think the perceived increased health risk of farmed salmon isn't worth the cheaper price.

CTV's Sarah Galashan contributed to this report.