Air Pollution Exposures During Adulthood and Risk of Endometriosis in the Nurses’ Health Study II

BACKGROUND Particulate matter and proximity to large roadways may promote disease mechanisms, including systemic inflammation, hormonal alteration, and vascular proliferation, that may contribute to the development and severity of endometriosis. OBJECTIVE Our goal was to determine the association of air pollution exposures during adulthood, including distance to road, particulate matter<2.5 μm, between 2.5 and 10 μm, and <10 μm, (PM2.5, PM10-2.5, PM10), and timing of exposure with risk of endometriosis in the Nurses' Health Study II. METHODS Proximity to major roadways and outdoor levels of PM2.5, PM10-2.5, and PM10 were determined for all residential addresses from 1993 to 2007. Multivariable-adjusted time-varying Cox proportional hazard models were used to estimate the relation between these air pollution exposures and endometriosis risk. RESULTS Among 84,060 women, 2,486 incident cases of surgically confirmed endometriosis were identified over 710,230 person-years of follow-up. There was no evidence of an association between endometriosis risk and distance to road or exposure to PM2.5, PM10-2.5, or PM10 averaged over follow-up or during the previous 2- or 4-year period. CONCLUSIONS Traffic and air pollution exposures during adulthood were not associated with incident endometriosis in this cohort of women.