A cross-sectional study of environmental quality and the timing of menarche and menopause in India using national survey and environmental monitoring datasets

BACKGROUND: Reproductive timing, including age at menarche and menopause, reflects endocrine health and long-term disease risk. Environmental conditions such as air pollution, groundwater chemistry, and land use may influence reproductive timing, yet evidence from India remains limited. This study evaluates associations between airborne fine particulate matter, groundwater characteristics, land use, and delayed menarche and earlier menopause among Indian women. METHODS: ), groundwater monitoring data from the Central Ground Water Board, and remote-sensing land use indicators. Late menarche among women aged 15-24 was analysed using logistic regression, and early menopause among women aged 30-49 using time-to-event models. Models accounted for demographic, socioeconomic, and geographic factors. RESULTS: and poorer groundwater quality increases the likelihood of deviations from typical reproductive timing. In contrast, greater surrounding green cover show lower likelihood of both late menarche and earlier menopause. CONCLUSIONS: Environmental conditions appear to influence reproductive timing among women in India. Improving air and groundwater quality and increasing green space may support healthier reproductive outcomes.