Childhood cancer risk in offspring of mothers occupationally exposed to hydrocarbon solvents

Little is known about maternal occupational exposure to hydrocarbons and offspring cancer risk. We aimed to estimate childhood cancer risk associated with maternal exposure to aliphatic/alicyclic, aromatic, and chlorinated hydrocarbons, and methylene chloride, trichloroethylene, 1,1,1-trichloroethane, and toluene. In this case-control study, all cancer cases ( N = 10 442) diagnosed at less than 20 years (born 1968-2016) in Denmark were matched to 261 050 cancer-free controls (25 : 1 matching ratio). Maternal exposure during pregnancy was determined from a job-exposure matrix. We performed unconditional logistic regression to estimate cancer risks from hydrocarbon exposures, adjusting for maternal age, maternal birthplace, and the child's birthplace. For medulloblastoma, we observed strong associations with maternal occupational exposure to chlorinated hydrocarbons [adjusted odds ratio (aOR): 2.33, 95% confidence interval (CI): 1.29-4.20] including the individual solvents: trichloroethylene (aOR: 1.76, 95% CI: 1.08-2.88) and methylene chloride (aOR: 1.62, 95% CI: 0.98-2.68). The risk of medulloblastoma also increased with maternal exposure to aliphatic/alicyclic hydrocarbons (aOR: 1.78, 95% CI: 0.99-3.20), aromatic hydrocarbons (aOR: 1.64, 95% CI: 0.93-2.89), and toluene (aOR: 1.83, 95% CI: 1.04-3.22). The risk of non-Hodgkin lymphoma (NHL) increased with exposure to chlorinated hydrocarbons (aOR: 1.95, 95% CI: 1.09-3.51). The strongest association with acute lymphoblastic leukemia (ALL) was observed for aromatic hydrocarbons (aOR: 1.35, 95% CI: 1.07-1.71). We saw increased risks in medulloblastoma, NHL, and ALL in offspring of mothers occupationally exposed to solvents in pregnancy over a span of 50 years in Denmark. We encourage maternal workplace safety measures that reduce exposures in pregnancy to improve children's health.