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

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. We linked individual health data from the National Family Health Survey (2019–2021) with satellite-derived estimates of fine particulate matter (PM2.5), 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. Exposure to PM2.5 above 40 μg/m³ is associated with a higher likelihood of late menarche (adjusted odds ratio, AOR 1.24) and earlier menopause (hazard ratio, HR 1.23), with stronger patterns in northern India. Groundwater arsenic concentrations greater than 0.01 mg/L are associated with delayed menarche (AOR 1.06) and earlier menopause (HR 1.14), while higher fluoride levels are linked to earlier menopause (HR 1.12). Combined exposure to elevated PM2.5 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. 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. Women’s reproductive health can be affected by the quality of the environment in which they live. This study examined whether air pollution and drinking water quality are linked to the age at which Indian women start menstruation (menarche) and stop menstruating (menopause). Using national survey data combined with information about air pollution and groundwater quality, we looked at rates of late menarche in young women and early menopause in older women. We found that higher levels of fine PM2.5 and poor groundwater quality, especially the presence of arsenic and fluoride, were linked to delayed menarche and earlier menopause. Also, people living in areas with more green cover showed healthier reproductive timing. These findings suggest that improving air and water quality could help support women’s reproductive health and guide future public health and environmental policies in India. Chattopadhyay et al. examine whether exposure to ambient PM2.5 air pollution and groundwater quality is associated with menarche and menopause timing among women in India. Higher PM2.5 and poor groundwater quality are associated with delayed menarche and earlier menopause, while greener environments are linked to healthier reproductive timing.