Association between PM_2.5 and its components and antral follicle count: A multicity study in Chinese adults

Antral follicle count (AFC) is a key biomarker of ovarian reserve, however, its association with fine particulate matter (PM_2.5) and its chemical components remains inadequately understood. In this study, we estimated the effects of PM_2.5 mass and its components including sulfate (SO₄^2-), nitrate (NO₃^-), ammonium (NH₄⁺), organic matter (OM), and black carbon (BC) on AFC among women of reproductive age. We included 4053 women seeking infertility treatment in Sichuan and Hubei provinces, China. A multivariable negative binomial mixed-effect model with city as a random effect was employed to estimate the associations between PM_2.5 and its components and AFC. Weighted quantile sum regression analysis was performed to evaluate the joint effect of PM_2.5 components on AFC. Our findings showed that exposure to PM_2.5 mass, SO₄^2-,NO₃^-,NH₄⁺, OM, and BC was associated with lower AFC. These results suggest that exposure to ambient PM_2.5 and its chemical components may impair ovarian reserve. Targeted reduction of specific air pollutants represents a potential strategy to protect female reproductive health.