Expert View: So should we be scared of salmon?

Food-related health risks are receiving ever greater media attention. In the past few weeks alone there have been scares concerning bird flu in Asia and salmon farming in Scotland. And because of their distrust of the authorities and their increasingly risk-averse attitude to food, consumers are turning to the media - including the internet - for information to help them decide what is safe to eat.

A move towards a more transparent and open society should be welcomed, as it is needed to win back public confidence in our policy-makers, but there are clearly some teething problems here. In the case of the farmed salmon scare, the media should have worked to attenuate rather than amplify public fears. The study that caused the scare, published in Science magazine, indicated that wild salmon had lower levels of toxins known as organochlorines than farmed fish, and that farmed salmon from the North Atlantic had particularly high levels.

Such findings in themselves are not surprising. Of course wild salmon caught off the coast of Alaska, where there are virtually no people, let alone factories, would be freer of contaminants than Scottish salmon farmed in waters contaminated by a legacy of 200 years of industrialisation and overpopulation.

However, what the scientists did was in effect to act as policy-makers. From the data they had gathered, and using guidelines drawn up by the US Environmental Protection Agency (EPA), they concluded that the consumption of farmed salmon would lead to exposure to a variety of contaminants. They therefore advised consumers not to eat it more than three times a year.

It was this "policy" that made headline news. But the scientists' conclusion went against the recommendations of a large number of regulatory agencies, including the US Food and Drug Administration (FDA), the UK Food Standards Agency (FSA) and the World Health Organisation, which all say that the levels of harmful chemicals in farmed salmon fall within safe limits. Unlike those of the other regulators, the EPA method of calculating risk adds the different organochlorines together. In fact, at the height of the crisis, the FSA discounted the EPA guidelines and concluded that the benefits of eating farmed salmon outweighed any possible risks.

There are several lessons to be learnt here. First, there is a need for regulatory agencies to harmonise their standards. The EPA guidelines should not have differed so markedly from those of other food agencies.

Second, we cannot expect the public to compare regulatory guidelines from different countries and decide for themselves which are right or wrong, and we can't necessarily expect the media to do so either. In such cases, we as scientists have an obligation to work with the media to come up with accurate policy responses to food-related issues. Scientists also need to work on producing more accurate summaries of their findings. Had the authors of the Science article acknowledged that the EPA guidelines represented a hardline view, the public concern might not have been so great.

Finally, the media also has to develop its own guidelines to ensure that the information contained in its science-based and risk-related stories, and the sources these stories are based on, are accurate. In this regard it is good to see that BBC News has recently produced just such guidelines for its journalists. So, in these troubled times, the BBC is leading the way in setting standards for journalistic accuracy.

Professor Ragnar Lofstedt is director of the King's Centre for Risk Management at King's College London.