The US study that sparked the toxic salmon scare has been strongly defended by leading scientists following allegations from the fish farming industry that it was biased and flawed.
“It is based on sound science and the results are undeniable,” said George Lucier, former director of the US Department of Health’s national toxicological programme and author of more than 200 studies on toxic chemicals. He has been backed by at least three other independent US experts.
The study, by scientists from four US universities and published 10 days ago in the US journal Science, analysed the levels of cancer-causing PCBs, dioxins and pesticides in 700 salmon from around the world. It found that farmed salmon were much more contaminated than wild salmon.
Despite the criticisms that followed, the conclusion has not been seriously challenged. But the subsequent findings – that eating farmed Atlantic salmon “may pose health risks that detract from the beneficial effects of fish consumption” – has provoked bitter argument.
The salmon farming industry alleges the research was biased because it was funded by a trust founded on US oil money.
The role played by the $3.8 billion Pew Charitable Trust, which funds research into global pollution, was spelled out in the study, and highlighted by Science magazine, the journal of the American Association for the Advancement of Science, the world’s largest general federation of scientists. Any suggestion that Pew interfered has been denied by all involved.
Nevertheless, the Scottish salmon farming industry maintains it has been the victim of a global conspiracy. “This was a deliberately engineered food scare orchestrated to attack the salmon farming industry in Scotland,” said Brian Simpson, chief executive of Scottish Quality Salmon (SQS).
Science’s editor-in-chief Donald Kennedy dismissed the allegations. He said that the authors were all respected members of academic institutions. “Pew funded the study but left the authors free to publish their results without review,” he told the Sunday Herald, adding that Science’s peer-review process “is among the most rigorous in the scientific community”.
It has also been alleged that the study was flawed because it didn’t sample any wild Atlantic salmon. In the original study, the researchers said this was because “few are available commercially”. Instead they sampled the next best thing: wild salmon from the Pacific.
However, Amy Mathews Amos, who organised the collection of samples, told the online news service, IntraFish, that purchasers were specifically instructed to ask for farmed Atlantic salmon fillets.
The levels of contamination reported by the study have been accepted by both the Food Standards Agency (FSA) and Scottish Quality Salmon (SQS) in the UK. “The levels of dioxins and PCBs found in this study are in line with those that have previously been found by the FSA,” stated the FSA on January 8.
Simpson added: “[The scientists] only repeated what is in the public domain and everyone has known for years.” He said that the comparison between farmed and wild salmon was a “red herring” because all the contamination was within safety limits.
The Sunday Herald revealed last week that official assumptions on the toxicity of the contamination have been challenged by scientists from the government’s Central Science Laboratory in York. They said that people eating a single portion of salmon a week would exceed the World Health Organisation safety limit for dioxins.
The salmon industry was first alerted to the Science study by a talk given to an aquaculture conference in Vancouver, Canada, on October 27 last year. Charles Santerre, of Purdue University in Indiana, said: “Expect this bombshell to be spun in an unfavourable manner, so I think the industry needs to be prepared for it.”
Although Santerre was widely quoted as a leading critic of the Science study last week, it was not always made clear that he is a paid consultant of industry group, Salmon of the Americas, in Princeton, New Jersey.
The Scottish Green Party yesterday reiterated their call for an inquiry, and have been backed by David Hunter, a consultant to the fish farming industry, who urged the Scottish Executive to act to safeguard the reputation of Scottish salmon.
Green MSP Robin Harper said: “The growing concern over the effects of toxic contaminants on public health demands a better response than rushing to deny scientific research out of hand. Denial and talk of conspiracies only increases people’s suspicions.”