Paternal exposure to hydrocarbon solvents in the workplace and cancer risk in children and adolescents.

[BACKGROUND] According to the International Agency for Research on Cancer, certain hydrocarbons are known or suspected carcinogens.

[OBJECTIVE] Our study aimed to estimate cancer risks in children and adolescents associated with paternal exposure to groups of aliphatic/alicyclic, aromatic, and chlorinated hydrocarbons, and the individual chemicals, toluene, methylene chloride, trichloroethylene, and 1,1,1-trichloroethane, from 3 months preconception to birth.

[METHODS] For this population-based case-control study of Danish children and adolescents (born 1968-2013) < 20 years of age when diagnosed with cancer 1968-2016, 10,442 cancer cases were matched to 261,050 cancer-free controls (25:1 matching ratio by sex and birth year). Paternal occupational exposure to hydrocarbons was generated by job-exposure matrices to span the time 3 months before conception until the child's birthdate. We employed unconditional logistic regression to estimate cancer risks in children and adolescents whose fathers were exposed to hydrocarbons, compared to those born to unexposed employed fathers and examined associations by exposure status (any or high/low vs. unexposed).

[RESULTS] We found consistent associations for several hydrocarbon solvents and glioma, acute myeloid leukemia (AML), and osteosarcoma in children and adolescents. The risk of glioma was highest in children and adolescents whose fathers were highly exposed to chlorinated hydrocarbons (low exposure: adjusted Odds Ratio (aOR): 1.24; 95% Confidence Interval (CI): 0.88, 1.74; high exposure: aOR: 1.68; 95% CI: 1.10, 2.57), while AML risk was increased when fathers were highly exposed to aliphatic/alicyclic hydrocarbons (low: aOR: 1.08; 95% CI: 0.68, 1.71; high: aOR: 1.87; 95% CI: 1.25, 2.78). The risk of osteosarcoma increased in children and adolescents with fathers highly exposed to 1,1,1-trichloroethane (low: aOR: 1.27; 95% CI: 0.65, 2.45; high: aOR: 2.14; 95% CI: 1.20, 3.82).

[SIGNIFICANCE] Our findings in Denmark suggest that paternal hydrocarbon exposure in the preconception and pregnancy periods may increase the risk of certain cancers in their children and adolescents.

[IMPACT] This study comprehensively evaluates paternal occupational exposure to solvents in relation to childhood cancer using nationwide registry data. By leveraging high-quality Danish occupational histories and robust exposure assessment methods, we contribute to narrowing the research gap in paternal environmental contributions to early-life carcinogenesis. Our findings provide new insights into preconception paternal risk factors and highlight the need for future prevention strategies.