Parental occupation and intracranial neoplasms of childhood: results of a case-control interview study

Abstract

In 1983-1984, the authors conducted a case-control study of environmental factors and childhood brain tumor risk. Cases (n = 110) were identified through the tumor registry of a pediatric hospital and matched controls (n = 193) through random digit dialing. In addition to parental occupational histories, telephone interviews elicited information about potential confounders and hypothesized risk factors for childhood brain tumors. Relying primarily on the Hoar et al. (J Occup Med 1980;22:722-6) job-exposure matrix, the authors examined parental employment characteristics in relation to the relevant developmental periods. Paternal employment in several industries (agriculture, construction, metal, and food and tobacco) and in several occupations (agriculture, benchwork, and transportation) was associated with excess risk. The range of notably elevated odds ratios was 2.0-3.3, with all confidence intervals including 1.0 except one. Elevated but unstable odds ratios were also found for both paternal and maternal employment in jobs "clustered" together because of common exposures. For both approaches to exposure classification, the greatest excess risks were consistently demonstrated for parental jobs held in the preconception period. Job-exposure matrix analyses indicated that case fathers were more likely than control fathers to have had jobs linked with aromatic amino and aromatic nitro compounds (range of notably elevated (and unstable) odds ratios, 3.4-4.4), but here the greatest excess risks were exhibited in the postnatal period. Few associations emerged for maternal employment characteristics, although this is probably explained by the relatively small number of women employed in jobs outside the home.