Maternal and Paternal Household Pesticide Exposure During Pregnancy and Risk of Childhood Acute Lymphoblastic Leukemia.

OBJECTIVE:The aim of this study was to investigate whether risk estimates for childhood acute lymphoblastic leukemia change when restricting model comparison groups to "nonpesticide exposure" (NPE10) households. METHODS:Cases ( n = 1810) 15 years or younger were identified through Children's Cancer Group institutions between 1989 and 1993 and age-/sex-matched to controls ( n = 1951). Household pesticide use during pregnancy/month prior was collected via telephone. NPE10 comparison group reporting no parental exposure to 10 pesticide classes was identified. RESULTS:Adjusted odds ratios increased from 15% to 49% when limiting the comparison to NPE10. Maternal termite insecticide exposure was associated with greatest risk (adjusted odds ratio, 4.21; 95% confidence interval, 2.00-8.88). There was minimal evidence of interaction by child sex or occupational pesticide exposure, and no monotonic dose-response pattern with frequency of use (times per year). CONCLUSIONS:Elevated risks are consistent with published pooled-/meta-analyses and DNA damage. The consistency and magnitude of these associations warrant product labeling, exposure reduction interventions, or both.