Parental occupational exposure to hydrocarbons and risk of acute lymphocytic leukemia in offspring

Parental exposure to hydrocarbons at work has been suggested to increase th e risk of childhood leukemia. Evidence, however, is not entirely consistent . Very few studies have evaluated the potential parental occupational hazar ds by exposure time windows. The Children's Cancer Group recently completed a large-scale case-control study involving 1842 acute lymphocytic leukemia (ALL) cases and 1986 matched controls. The study examined the association of self-reported occupational exposure to various hydrocarbons among parent s with risk of childhood ALL by exposure time window, immunophenotype of AL L, and age at diagnosis. We found that maternal exposure to solvents [odds ratio (OR), 1.8; 95% confidence interval (CI), 1.3-2.5] and paints or thinn ers (OR, 1.6; 95% CI, 1.2-2.2) during the preconception period (OR, 1.6; 95 % CI, 1.1-2.3) and during pregnancy (OR, 1.7; 95% CI, 1.2-2.3) and to plast ic materials during the postnatal period (OR, 2.2; 95% CI, 1.0-4.7) were re lated to an increased risk of childhood ALL, A positive association between ALL and paternal exposure to plastic materials during the preconception pe riod was also found (OR, 1.4; 95% CI, 1.0-1.9), The ALL risk associated wit h parental exposures to hydrocarbons did not vary greatly with immunophenot ype of ALL. These results suggest that the effect of parental occupational exposure to hydrocarbons on offspring may depend on the type of hydrocarbon and the timing of the exposure.