Meeting clean air targets could reduce the burden of hypertension among women of reproductive age in India

Air pollution is one of the leading risk factors for hypertension globally. However, limited epidemiological evidence exists in developing countries, specifically with indigenous health data and for fine particulate matter (PM2.5) composition. Here, we addressed this knowledge gap in India. Using a logistic regression model, we estimated the association between hypertension (systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg) prevalence among women of reproductive age (WRA, 15-49 years) from the fifth round of the National Family Health Survey and long-term exposure to PM2.5 and its composition, after adjusting for confounders. We also explored the moderating effects of socioeconomic indicators through a multiplicative interaction with PM2.5. Hypertension prevalence increased by 5.2% (95% uncertainty interval: 4.8%-5.7%) for every 10 μg/m3 increase in ambient PM2.5 exposure. Significant moderating effects were observed among smokers against nonsmokers and for various sociodemographic parameters. Among PM2.5 species, every interquartile range increase in black carbon (BC) and sulphate exposure was significantly associated with higher odds of hypertension than for organic carbon and dust. We estimated that achieving the National Clean Air Program target and World Health Organization air quality guidelines can potentially reduce hypertension prevalence by 2.42% and 4.21%, respectively. Our results demonstrate that increasing ambient PM2.5 exposure is associated with a higher prevalence of hypertension among WRA in India. The risk is not uniform across various PM2.5 species and is higher with BC and sulphate. Achieving clean air targets can substantially reduce the hypertension burden in this population.