Frustratingly, hazard and risk have very different meanings for scientists, yet the media, when talking about food safety, sometimes use them interchangeably.
The need to distinguish between the intrinsic toxicity of the contaminant – the hazard – and the real risk to an individual according to how much is taken into their body through food, and other routes, is at the heart of the FSA's food safety remit. As many of you will know, this is not a new idea. In the 16th century, Paracelsus taught that ‘the dose makes the poison’, and we know that in order to work out what effect a contaminant might have on our health, it is essential to assess the toxicological risks of a contaminant at the levels present in food, taking account of scientific uncertainties, consumption patterns and groups of people who may be especially susceptible. This approach enables us to offer an independent assessment of the risk, setting out all of the evidence, analysis and uncertainties that underpin our conclusions.
Increased scientific knowledge does not always make it easier to communicate this advice to the consumer. Developments in analytical chemistry have made it possible to detect smaller and smaller quantities of contaminants and adulterants in food. These advances can make important contributions to food safety when, say, dealing with chemicals that can cause cancer by damaging our DNA for which there is no safe level. However, many contaminants are potent acute or chronic toxins at high doses, but may have little or no implication for human health at the levels to which people are generally exposed.
The really big challenge is how to communicate risk effectively. We’ve all seen it done badly when it reaches the headlines as a percentage – you know the kind of thing – ‘reduce your chance of developing a cancer by 10% if you eat some such', which made me recall Michael Blastland’s article on the BBC website a couple of months ago in which, illuminatingly, he urged us all ditch percentages and talk instead about numbers of real people affected in the population. Why not have a look yourself at the approach he suggests – do you think that it helps to clarify messages about risk? Let me know what you think.