Associations of long-term exposure to fine particulate matter and its components with ovarian aging: Evidence from a cross-sectional study in China

This study aimed to investigate associations between long-term exposure to PM2.5, or its constituents, and ovarian aging, assessed by age at natural menopause (ANM) and early menopause (EM) prevalence. A total of 15,345 postmenopausal women were recruited from an epidemiologic survey conducted across 12 provinces in China (2023-2024). Concentrations of air pollutants [PM2.5 mass, sulfate (SO₄²⁻), nitrate (NO₃⁻), ammonium (NH₄⁺), organic matter (OM), and black carbon (BC)] were obtained from the Tracking Air Pollution in China database. Multivariable regression models with random effects and quantile g-computation models were used to evaluate associations. Each interquartile range increase in 5-year average concentrations of PM2.5, SO₄²⁻, NO₃⁻, NH₄⁺, OM, or BC were correlated with significant changes of -0.79 (95 %CI: -0.87, -0.72), -0.98 (95 %CI: -1.06, -0.90), -0.54 (95 %CI: -0.63, -0.45), -0.90 (95 %CI: -0.98, -0.81), -0.83 (95 %CI: -0.91, -0.76), and -1.02 (95 %CI: -1.09, -0.96) in ANM, respectively. Joint exposure analysis revealed that the five combined PM2.5 constituents shared a negative association with ANM in which BC provided the largest weight. These pollutants were also significantly associated with elevated EM prevalence, wherein BC provided the strongest contribution. The associations were stronger in women with a history of smoking, other hazardous environmental exposure, and lower education level.