More about the work of the COC

Tuesday 18 December 2001

Professor Peter Blain, Chair of the Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment, is interviewed about the Committee's work.

Dietary factors have long been recognised as playing an important role in the development of cancer and many people remain concerned that some food additives and contaminants may be carcinogenic. Since its establishment in 1978, the Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (COC) has assessed the carcinogenic risks of a range of substances used as food additives as well as substances used in household goods, toiletries and other preparations.

Recently, COC assessed the risks from certain dichloropropanol contaminants in food and concluded, on the grounds that these chemicals were genotoxic carcinogens in animals, that the levels should be reduced to as low as is reasonably practical.

The Committee has 13 members from various backgrounds in cancer epidemiology, biostatistics, genetics, environmental carcinogenesis, cell biology, pathology and chemistry, and one lay member. It is chaired by Professor Peter Blain, Head of the Department of Environmental and Occupational Medicine at the University of Newcastle.

The level of risk associated with many potentially carcinogenic substances is not always easy to understand, so the Committee is aware of the importance of communicating risk to the public in a comprehensible way.

'We are lucky to have a lay member on the Committee who is very good at making us speak plain English. I think when you’re communicating with the public, you have to remember that there's a broad range of experience and understanding among them,' Professor Blain says.

'Sometimes it is helpful to give people a comparison of risk, so that they can put it into the day-to-day context of their lives and understand it better. Such comparisons are very important, because if you tell someone that a particular chemical poses a cancer risk, they see that as a certainty,' he explains. 'They don’t see it as an improbable event. It’s about being able to make people appreciate the idea that probability is not certainty.'

It is also important to remember that there are naturally occurring carcinogens in foods, he adds.

'Part of the debate over food additives is that, on the one hand, chemicals are being added to natural food substances with the intention of reducing the risk of food spoiling. On the other hand, people say: 'You're adding things to foods and that must be harmful.' We aim to ensure that food additives are safe. If they weren’t used, foods would go off quicker and there would be other problems with spoiling agents, which themselves might be toxic. So there’s a balance - just because food is natural doesn’t mean that it’s necessarily always safe.'

During 2001 the Committee sponsored a joint workshop with the Committee on Mutagenicity and the Committee on Toxicity on genomics, proteomics (the study of protein structure and function) and toxicology. The aim was to help guide all three bodies on how the new genetics could be used in the risk assessment process for mutagenicity, carcinogenicity and toxicity.

COC is also investigating genetic susceptibility to cancer and is pulling together all relevant scientific literature on the subject. 'We’re planning to publish a report on the importance of genetic susceptibility in risk assessment,' Professor Blain says.

At the same time as they issue advice on certain products, all scientific advisory committees are keen to ensure they remain objective and independent. 'This is a rather contentious issue,' says Professor Blain, 'because no matter what opinion we give, there will always be people - either the public or groups with commercial interests - who disagree with us. If our opinion appears to be on one side or the other, there will be cries that we are not being objective.

'Also, it’s vital to convey that there is no such thing as absolute food safety, just minimal risk. When you look at additional risks from chemicals in food, you have to make a decision as to what is, and is not, an acceptable level of risk. These sorts of decisions are largely social and political in nature.'