Professor Sir Colin Berry is not a big fan of the 'precautionary principle', the idea that scientists, medical researchers, technologists and just about everybody else these days should err on the side of caution lest they cause harm to human health or the environment. Berry is one of Britain's leading scientists; he has held some of the most prestigious posts in British medicine, including head of the Department of Morbid Anatomy at the Royal London Hospital from 1976 to 2002. Now he watches as his 'good profession' threatens to be undermined by what he says is an 'unscientific demand' to put precaution first.
One of the most common definitions of the precautionary principle is that put forward by Soren Holm and John Harris in their critique of it in Nature magazine in 1999: 'When an activity raises threats of serious or irreversible harm to human health or the environment, precautionary measures that prevent the possibility of harm shall be taken even if the causal link between the activity and the possible harm has not been proven or the causal link is weak and the harm is unlikely to occur.' For Berry, this is one of the biggest problems with the precautionary principle - the notion that we could ever fully predict the outcome of an experiment or piece of research before it is complete, and that if we can't then we should play it safe. 'It doesn't allow for the unknown', he says. 'Or for taking a risk in order to do something potentially useful.'
Berry says it is in the nature of scientific and medical research that you start out before you have all the information to hand - indeed, almost all of the great scientific advancements of the past 200 years have been a process of 'learning as we went along'. 'Consider blood transfusions', he says. 'When we started doing them, we knew about some blood groups but there were others we didn't know about. We only came to know of these other blood groups when patients started to have transfusion reactions. There was an unknown, but we were able to learn from it and refine the process.'
He wonders whether, if the precautionary principle had been about for the past 200 years rather than the past 20, breakthroughs such as blood transfusions would ever have been made. 'I certainly don't think we would have radiotherapy or the various applications of x-rays if Marie Curie had been under pressure to comply with the precautionary principle', he says. In the early twentieth century, Polish-born physicist and chemist Curie devoted her working life to the study of radium, paving the way for nuclear physics and the treatment of cancer. It cost her her life - she died from leukaemia in 1934, almost blind, her fingers burned by radium. 'Curie's work caused her "irreversible harm"', says Berry. 'The precautionary principle would not have permitted her to take such risks, and the world would have been a worse place for it.'...
Berry points to the restrictions imposed on DDT - the pesticide used to get rid of malaria-carrying mosquitoes - as another example of how the 'application of precaution' can cause death and disease. In some third world countries where malaria had been all but eradicated over the past 20 years, there have been epidemics of the disease since DDT was restricted. Currently malaria is on the rise in all the tropical regions of the planet; in 2000, it killed more than one million and made 300million seriously ill. 'Campaigners claimed that DDT was bad for the environment; they said that it caused harm to American birds of prey. I'm sorry, but why should people in the third world at risk from malaria care about American birds of prey? Decisions about these things should be based on local needs and on empirical evidence.'
The same should go for genetically modified crops, reckons Berry. 'If we want to miss out on this new technology, that's our lookout. But we should not be in a position to restrict the use of GM in the third world. As an African said recently, "You go ahead and ban GM crops, but can we eat first?"' Berry says the restriction of the use of potentially life-saving technologies in the third world is 'a kind of environmental imperialism - if something is perceived to be bad for some American bird, then no one else in the world can use it either. That is absurd; we really cannot go on like this.'...
'Almost no new technology can be assured to be risk-free. If your position is that you don't accept any incremental risk, you are in effect saying no to all new technologies, whether it be a better anaesthetic, a better car, a better aeroplane, a safer environment for children - in fact anything worth having.'
Wednesday, July 21, 2004
From "More sorry than safe" (Spiked-online.com), by Brendan O'Neill: