Childhood leukaemia in Great Britain and fallout from nuclear weapons testing

The possible effects of radiation from fallout on childhood leukaemia mortality from 1950 to 1987 and registrations from 1963 to 1987 were assessed using a division of Great Britain into regions with higher rainfall and a consequently higher fallout radiation dose in the 1960s and regions with lower rainfall and a lower radiation dose. Childhood leukaemia mortality rates declined and registration rates increased throughout the period. For ages 0-14 years, the differences between rates in wet regions and dry regions were small and appeared unrelated to periods of low, medium and high radiation exposure based on dose equivalent to the red bone marrow after birth. For the 0-4 years age group the highest ratios of leukaemia death rates and registration rates in the wet compared with the dry part of Great Britain occurred in the period of highest radiation exposure after birth. The death rate ratio was significantly raised in the period of high exposure compared with the surrounding medium exposure periods, but the difference in registration rate ratios between the high exposure period and the medium exposure period following was not statistically significant. The results might be explained by survival and registration changes, or chance in the case of registrations, but do not exclude the possibility that low doses of radiation from fallout were responsible for an increased risk of leukaemia in young children in Great Britain. (author)