Disparity in non-communicable disease burden attributable to ambient PM_2.5 exposure among adult population subgroups...

Ambient fine particulate matter (PM_2.5) exposure is a leading risk factor for non-communicable diseases (NCDs) globally. Yet gaps remain in understanding the disparities in PM_2.5-related NCD burdens across population subgroups, especially in low- and middle-income countries like India.

The main aim of this work is to address this gap by examining how the ambient PM_2.5-attributable burden of three NCDs (diabetes, high blood pressure, and heart disease) varied across demographic subgroups in India, where people are exposed to some of the highest PM_2.5 levels.

Using nationally representative socio-demographic and health information from the National Family Health Survey (NFHS-4 and NFHS-5), covering approximately 1.49 million individuals aged 15-49 years, we employed a hierarchical logistic mixed-effects model to estimate associations between satellite-derived ambient PM_2.5 exposure and the odds of diabetes, high blood pressure, and heart disease, stratified by gender, wealth, and caste-based subgroups, and adjusted for relevant covariates, using data from the National Family Health Survey. These subgroup-specific risk estimates were then used to assess disparities in ambient PM_2.5-attributable NCD burden.

The associations between PM_2.5 exposure and the three NCDs were stronger in males (Odds Ratio, OR: 1.047, 95% confidence intervals: 1.041-1.053) than in females (OR: 1.033, 1.027-1.039) and in other backward classes (OBC) (OR: 1.079, 1.075-1.083) than in their demographic counterparts. While the richest subgroup was most vulnerable to PM_2.5-related diabetes risk (OR: 1.063, 1.056-1.07), with risk decreasing across lower wealth-index categories, the pattern was reversed for heart disease and high blood pressure. The morbidity burden attributable to PM_2.5 was higher among males, OBC, and disadvantaged subgroups (2.04-11.8 million) than among their demographic counterparts.

Our findings underscore the need for equity-focused policies targeting vulnerable subgroups to reduce disparities in environmental health burdens in India.

This study quantifies socio-demographic disparities in ambient PM_2.5-attributable burden of diabetes, high blood pressure, and heart disease across India using nationally representative socio-demographic and health database. The findings identify population subgroups disproportionately affected by air pollution, providing policy-relevant evidence to guide equitable clean-air strategies. Because NFHS health measurements were limited to adults aged 15-49 years, the estimated disparities likely represent a conservative assessment of the true population-level burden.