Exposures to Drinking Water Contaminants in Community Water Systems and Risk of Ovarian Cancer in the California Teachers Study Cohort.

Almost all women (>99%) had average exposures below regulatory limits for all contaminants.

Findings were similar in models adjusted for other contaminants.

We observed positive but imprecise associations for arsenic and total trihalomethanes in single-contaminant and contaminant-adjusted analyses.

Uranium was the largest contributor (56%) to the mixture effect for all ovarian cancers, and nitrate was the largest contributor (48%) for the high-grade serous histotype.