Prenatal Exposure to Air Toxics and Malignant Germ Cell Tumors in Young Children.

Objective: To assess prenatal air toxics exposure and risk for childhood germ cell tumors (GCTs) by histological subtype (yolk sac tumor and teratoma).

Methods: In this case-control study, GCT cases less than 6 years (n = 243) identified from California Cancer Registry records were matched by birth year to cancer-free population controls (n = 147,100), 1984 to 2013. Routinely monitored air toxic exposures were linked to subjects' birth address. Logistic regression estimated GCT risks per interquartile range increase in exposure.

Results: Prenatal exposure to various highly-correlated, traffic-related air toxics during the second trimester increased GCT risk, particularly 1,3-butadiene (odds ratio [OR] = 1.51; 95% confidence interval [CI] = 1.01, 2.26) and meta/para-xylene (OR = 1.56; 95% CI = 1.10, 2.21). Analyses by subtype indicated elevated ORs for yolk sac tumors but not teratomas.

Conclusion: Our estimated ORs are consistent with positive associations between some prenatal traffic-related air toxics and GCT risk, notably yolk sac tumors.