Childhood cancers, birthplaces, incinerators and landfill sites

Background In all, 70 municipal incinerators, 307 hospital incinerators and 460 toxic-waste landfill sites in Great Britain were examined for evidence of effluents causing childhood cancers. Municipal incinerators had previously shown significant excesses of adult cancers within 7.5 and 3.0 km. The relative risks for adults had been marginal and an analysis of childhood cancers seemed to offer a more sensitive approach. Methods A newly developed technique of analysis compares distances from suspect sources to the birth addresses and to the death addresses of cancer-children who had moved house. A localized hazard, effective at only one of these times, must be preferentially associated with the corresponding address. This creates an asymmetry of migrations towards or away from age-restricted effective sources. Results The child-cancer/leukaemia data showed no systematic migration-asymmetries around toxic-waste landfill sites; but showed highly significant excesses of migrations away from birthplaces close to municipal incinerators. Relative risks within 5.0 km of these sites were about 2:1. Hospital incinerators gave analogous results. The ratios greatly exceed findings around 'non-combustion' urban sites. Conclusions Because of their locations, the specific effects of the municipal incinerators could not be separated dearly from those of adjacent industrial sources of combustion-effluents. Both were probably carcinogenic. Landfill waste sites showed no such effect.