Childhood cancer mortality in relation to the St Lucie nuclear power station

Abstract

An unusual county-wide excess of childhood cancers of brain and other nervous tissue inthe late 1990s in St Lucie County, Florida, prompted the Florida Department of Health toconduct a case–control study within the county assessing residential chemical exposures.No clear associations were found, but claims were then made that the release ofradioactive substances such as strontium 90 from the St Lucie nuclear powerstation, which began operating in 1976, might have played a role. To test theplausibility of this hypothesis, we extended by 17 years a previous study of countymortality conducted by the National Cancer Institute. Rates of total cancer,leukaemia and cancer of brain and other nervous tissue in children and across allages in St Lucie County were evaluated with respect to the years before andafter the nuclear power station began operation and contrasted with rates intwo similar counties in Florida (Polk and Volusia). Over the prolonged period1950–2000, no unusual patterns of childhood cancer mortality were found for StLucie County as a whole. In particular, no unusual patterns of childhood cancermortality were seen in relation to the start-up of the St Lucie nuclear power stationin 1976. Further, there were no significant differences in mortality between thestudy and comparison counties for any cancer in the time period after the powerstation was in operation. Relative rates for all childhood cancers and for childhoodleukaemia were higher before the nuclear facility began operating than after, whilerates of brain and other nervous tissue cancer were slightly lower in St LucieCounty than in the two comparison counties for both time periods. Althoughdefinitive conclusions cannot be drawn from descriptive studies, these data provideno support for the hypothesis that the operation of the St Lucie nuclear powerstation has adversely affected the cancer mortality experience of county residents.