BACKGROUND: In a recent population-based case-control study using 2,400 cases of childhood cancer, we found a statistically significant association between residential radon and acute lymphoblastic leukemia risk.
HYPOTHESIS: Traffic exhaust in the air enhances the risk association between radon and childhood leukemia.
METHODS: We included 985 cases of childhood leukemia and 1,969 control children. We used validated models to calculate residential radon and street NO(x) concentrations for each home. Conditional logistic regression analyses were used to analyze the effect of radon on childhood leukemia risk within different strata of air pollution and traffic density.