HEALTH / Second Opinion

TUMOUR specialists and other doctors spend much of their time attempting to demystify cancer. Someone told he or she has cancer is still quite likely to react by asking: 'What have I done to deserve this? I've lived an honest life.' The belief that cancer is a punishment inflicted by a malign God is, fortunately, becoming less widespread, but it has been replaced by another belief - that cancers are caused by technology.

The past month has seen further confusion in the long controversy about the links between childhood cancers around Sellafield, Dounreay, and other nuclear installations. There is no dispute that more cases of leukaemia than would be expected have occurred in some of these communities. Some experts believe that the explanation is exposure of the children's fathers to radiation; others believe that the leukaemias were due to viruses brought into isolated rural communities by construction workers. None of the theories provides a totally convincing answer. Whatever the cause, however, the children who have developed leukaemia around nuclear plants are only a tiny fraction of the total, and for the overwhelming majority the cause of the disease remains unknown.

Electric power supplies have also been blamed not only for childhood leukaemia but also for brain tumours, the second most common type of cancer in children. A link was first suggested in the 1970s, since when a succession of research reports have given divergent results. A recent study in Denmark concluded that if there was an association the number of children whose cancers were due to electric fields was very small.

Why should nuclear power and electromagnetic radiation be blamed for cancer when the evidence shows that either they have no effect or that, at worst, they might account for a fraction of all childhood cancers? Part of the answer is the distrust people feel for science. The many examples of technological and environmental disasters - the unexpected side-effects of drugs and pesticides; holes in the ozone layer; HIV- contaminated blood transfusions - have led to a feeling that science may be out of control and that the scientific establishment is concealing its mistakes from the public.

The other explanation is that looking for something to blame is part of the natural human response to sudden illness. Primitive societies put the blame on witchcraft; ours used to blame God and now suspects science. Clearing away such suspicions is not easy. Australian and American servicemen who fought in Vietnam and later developed cancer blamed the herbicide Agent Orange and have refused to accept that no link can be shown. More recently they have blamed dapsone, a drug used to treat malaria in Vietnam, and are unwilling to accept the scientific verdict of not guilty.

It is profoundly disappointing that after so much research the causes of childhood cancer remain largely unknown, but that is the position at present. (For adult cancers, by contrast, alcohol and tobacco account for close to half the total.) Finding someone or something to blame for a child's illness may help in the short-term, but long-term it may make it more difficult for the family to accept the disaster as a natural happening.