Source-specific fine particulates emission linked to prevalence of ophthalmic cases in India

Particulate Matter (PM) pollution is a prime component of air pollution and poses a substantial risk to human health, including the eye. This work envisioned to show the impact of PM_2·5 pollution on the Ophthalmic disease prevalence in India. This national-level observational-based cross-sectional retrospective study included the hospital-reported ophthalmic outpatients in 2019-20. The sector-wise high-resolution (0·1° × 0·1°) PM_2·5 emission data along with the annual average PM_2·5 concentration data for 2019 from NASA is adopted for the risk factor analysis. Nearly 32·6 million footfalls are recorded in various hospitals due to ophthalmic morbidity in 2019, out of which surprisingly ~ 80% of cases are registered in rural India. Half of the total ophthalmic disease burden comes from the top 100 districts out of the total 720 districts in India. The inferential analyses depicted a statistically significant positive correlation (r = 0·54, 95% CI 0·48 - 0·59, P < 0·001) between the PM_2·5 emission and ophthalmic outpatients. The risk of eye disease in the exposed rural population is 4 times higher than the unexposed population 4·19 (4·19 - 4·2). The PM_2·5 emission from household cooking activity shows a greater correlation (r² = 0·28, 95% CI 0·22 - 0·35, P < 0·001) with the occurrence of ophthalmic cases in India followed by incense stick and mosquito coil burning (r² = 0·28 (0·22 - 0·34)), and transportation (r² = 0·24 (0·18 - 0·29)). The meteorological parameters like temperature and humidity show very little association and precipitation shows a negative correlation with the number of ophthalmic outpatients in India. This study suggests that surface emission data could be a potential tool to link prevailing diseases in India.