Study finds toxins in farmed salmon, but still safe to eat, says government
Thu Jan 8, 6:48 PM ET
VICTORIA (CP) - Farm-raised salmon contain higher levels of potentially cancer-causing pollutants and dioxins than wild salmon, but that doesn't mean they aren't safe to eat, say Canadian industry and government officials.
Eating more than a meal of farm-raised Atlantic salmon a month, depending on its country of origin, could slightly increase the risk of getting cancer later in life, says an international study published Thursday in the U.S. journal Science.
The study tested contaminants in 700 salmon bought around the world, including Vancouver and Toronto, and found those farmed in Northern Europe contained the most pollutants, followed by North America and then Chile.
Researchers blamed the feed used on fish farms for concentrating ocean pollutants. It advised farmers to switch feed and recommended that consumers in the meantime eat more wild salmon.
But government and industry officials in British Columbia, where much of Canada's salmon farming sector is located, said pollution levels found in farmed salmon are still well below health guidelines set by the federal government.
Environmental groups said the study confirms earlier findings that potentially dangerous levels of toxic chemicals are contained in the feed given to farmed salmon in Canada and Europe.
"While European farmed fish are worse, Canadian farmed salmon are still a potential health risk," said Otto Langer, a marine conservation expert with the Vancouver-based David Suzuki Foundation.
The study stresses the need for Canada to modernize its regulations regarding the amount of PCBs and other chemicals acceptable for human consumption, he said.
A spokesman with the Canadian Food Inspection Agency said the study requires further examination, but its findings indicate pollutant levels in farm salmon that are currently below Health Canada standards.
"This study just came out, so really what needs to be done is it has to be presented as new scientific data and it needs to be carefully reviewed and evaluated," said Klaus Schallie, western Canada's aquaculture specialist with the agency.
"Certainly, if changes need to be made in the way we monitor or analyse the products or if Health Canada determines it's necessary to change the standard, that's going to happen.
"But at this time the levels that we're talking about are well, well within the Health Canada guidelines and the FDA (news - web sites) (U.S. Food and Drug Administration) and the EU (European Union (news - web sites)) guidelines for these chemicals and contaminants."
A biologist working for a salmon-farming company at Campbell River on Vancouver Island said he's not surprised the study found higher levels of contaminants in farmed salmon.
Tim O'Hara, senior biologist at Pan Fish Canada, said Atlantic salmon, the breed typically farmed worldwide, have a higher body fat content than wild salmon which results in them storing more contaminants in their oils.
"None of this is a surprise at all," he said. "Even the highest level - and I think it's the Scottish farmed salmon - is still about one-eightieth or one one-hundredth of the FDA warning level.
"In terms of it being a warning, or an at-risk warning, there's nothing in that."
A team of six researchers analysed two tonnes of farmed and wild salmon from around the world - about 700 fish - looking for organochlorine contaminants.
The results showed contamination levels far higher in farmed salmon than in wild fish.
European-raised salmon were the worst affected, especially those from Scottish fish farms, while North American salmon were not far behind. Farmed salmon from Chile had the lowest levels of the toxic materials, including PCBs and dioxins.
Farm-raised salmon contained significantly higher concentrations of 13 organochlorine pollutants, the study found. Among the most important are dioxins, which are released when industrial waste is burned, and PCBs, once widely used as insulating material.
The average dioxin level for farm-raised salmon was 11 times higher than in wild salmon - 1.88 parts per billion compared with 0.17 ppb. For PCBs, the average was 36.6 ppb in farm-raised salmon and 4.75 in wild.
Animals absorb those pollutants through the environment, storing them in fat that people then eat.
High levels are believed to increase the risk of certain cancers and, in pregnant or breast-feeding women, harm the developing brains of fetuses and infants.