A task-based assessment of parental occupational exposure to organic solvents and other compounds and the risk of childhood leukemia in California

- Leukemia is the most common cancer in children and its rate has increased overtime.
- 1795 families participated in a case-control study in California (48% Latinos).
- Parental exposures at work were assessed with task-based modules and expert rating.
- For Latino fathers only, several chemicals increased childhood leukemia risk.
- Prevalence of chemical exposures was low in mothers, and no associations were seen.

PurposeData on parental occupational exposures and risk of childhood leukemia lack specificity. Using 19 task-based job modules, we examined the relationship between occupational exposure to organic solvents and other compounds and the risk of leukemia in children.MethodsLatino (48%) and non-Latino (52%) children with acute lymphoblastic leukemia (ALL; n=670), acute myeloid leukemia (AML; n=104), and controls (n=1021) were enrolled in a study in California (2000-2008). Logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for socio-demographic factors.ResultsAmong children with non-Latino fathers, none of the exposures evaluated were associated with risks of ALL and AML. In contrast, exposure to any organic solvents in Latino fathers was associated with an increased risk of childhood ALL (OR=1.48; 95% CI: 1.01-2.16); in multivariable analyses, the OR for chlorinated hydrocarbons was 2.28 (95% CI: 0.97-5.37) while the ORs were close to one for aromatic hydrocarbons, glycol ethers, and other hydrocarbon mixtures. We also observed an increased risk of ALL with exposure to combustion exhaust/polycyclic aromatic hydrocarbons (PAHs) (ORs=1.70; 95% CI: 1.16-2.57, and 1.46; 95% CI: 0.94-2.26 with and without adjustment for chlorinated hydrocarbons, respectively). Moderately elevated risks of ALL were seen with exposure to metals, paints, and wood dust, although not statistically significant. An increased risk was reported for asbestos based on small numbers of exposed Latino fathers. No associations were reported between maternal exposures to any exposures and childhood ALL and AML.ConclusionsOur data support associations between paternal occupational exposures to chlorinated hydrocarbons, combustion exhaust, metals, and possibly asbestos and the risk of ALL in the children of Latino fathers only.