However, the UK Childhood Cancer Study - an 18-year study of EMFs and 2226 cancer-stricken children matched with healthy children - did not support a link between EMF exposure and childhood cancer (Lancet, 1999; 354: 1925-31).

Nevertheless, the authors noted that the study design may have been flawed (an admission omitted from most of the media reporting). A non-relevant criterion was used, and only 2.3 per cent of the studied children fell into the higher-exposure category. Exposure was also not comparable to studies in other countries, such as North America, where the voltage is different and rates of high exposure are greater. Another study in New Zealand (Lancet, 1999; 354: 1967-8) also proved inconclusive, but had the same design flaws as the UKCCS.

Overall, we know pitifully little about the role of environmental carcinogens in childhood cancer (Environ Health Perspect, 1998; 106 [Suppl 3]: 875-80). When studies have been done, scientists have tended to hedge their bets by concluding that the effects on the general population are likely to be small. But add up all these small effects and there may be a strong case for an environmental cause for some childhood cancers.

Also, whereas scientists now believe that many adult cancers are due to lifestyle factors such as smoking, diet, occupation, and exposure to radiation and toxic chemicals, medical science has consistently failed to give the same consideration to childhood cancers.

The average age for a diagnosis of childhood cancer is six years, yet children often have more advanced cancer at first diagnosis. Only about 10 per cent of adults show evidence of spreading disease when first diagnosed compared with 80 per cent in children.

Doctors say that such late diagnosis is because the symptoms of cancer mimic so many other childhood illnesses (Am Fam Physician, 2000; 61: 2144-54). However, another viewpoint is that many medics, believing that childhood cancer is rare, may not take the symptoms seriously and may see exploratory tests for youngsters as unnecessary.

In the US, Alexander Horwin died of the most common form of brain cancer - medulloblastoma - after his parents were told repeatedly by their paediatrician that he had a ‘virus’. His parents have since made a herculean effort to raise awareness of the potential links between childhood vaccinations and cancer (log on to www.ouralexander for details).

Perhaps our children’s increased vulnerability in the face of environmental risk factors combined with the alarming increase in the incidence of childhood cancer is our wake-up call, urging us to take the unique biology of children and the damaging potential of these environmental insults even more seriously.

Where cancer is concerned, the best form of cure is prevention, and it behooves us to do whatever we can to ensure that our children have the resources to remain healthy in a toxic world.

Pat Thomas