Risk of childhood leukemia and parental self-reported occupational exposure to chemicals, dusts, and fumes: results from pooled analyses of German population-based case-control studies.

A recent large-scale United States study reported an association between parental exposure to hydrocarbons at work and the risk of childhood leukemia. Parental occupational exposure to different chemicals and industrial dusts or fumes also was assessed in three German case-control studies that were conducted from 1992-1997. The design and methods of exposure assessment were similar for these studies; therefore, they were pooled for this analysis. In total, these three studies involved 1138 cases of acute lymphocytic leukemia (ALL) and 2962 controls. We found that maternal exposure to paints or lacquers during the preconception period (odds ratio, 1.6; 95% confidence interval, 1.1-2.4) and during the index pregnancy (odds ratio, 2.0; 95% confidence interval, 1.2-3.3) was related to an increased risk of childhood ALL. Whereas our findings for exposure to paints or lacquers confirmed observations from the United States study, we failed to confirm associations between risk of ALL and maternal exposure to solvents and parental exposure to plastic materials. Our studies provide some evidence that parental occupational exposure to certain substances may be associated with cancer risk in offspring; however, more specific studies are needed to identify such substances and the doses that may be hazardous.