Effect of ambient fine particulate matter (pm2.5) on hospitalizations from cardiovascular and respiratory morbidities in Bangladesh

Abstract

The available evidence on the acute health impacts of air pollution induced by fine particulate matter (PM2.5) in developing nations is considerably limited. The study assessed the short-term links between PM2.5 and daily cause-specific hospitalization in Bangladesh. Utilizing a nationwide time-series analysis encompassing 5 metropolitan cities from 2021 to 2022, Bayesian hierarchical models with fixed and random effects were employed to estimate national-average associations between PM2.5 levels and daily cause-specific hospitalization. City-specific effects of PM2.5 were determined with generalized additive models, adjusting for time trends, day of the week, weather conditions, holidays, and days of fasting period (Ramadan). During the study period, the average daily PM2.5 concentration across the study area Dhaka, Chittagong, Sylhet, and Khulna are respectively 113.9, 63.7, 76, 63.8, 83.8. The excess risk associated with a 10 µgm-3 increase of average PM2.5 concentration of current and past 3 days fine PM2.5 is largest for coronary heart disease (CHD) and the effect size is 2.33% (95% CI: 0.82 to 3.9%). The effect sizes for chronic obstructive pulmonary (COPD) and hypertension (HPT) are 2.22% (1.10 to 3.21%) and 2.14% (95% CI: 0.86 to 3.49%) respectively. The effect size of 4 days moving average PM2.5 for total respiratory and cardiovascular disease is statistically significant and excess risks of respiratory hospitalization (1.18%; 95% CI: 0.28 to 2.03%) is higher than that of cardiovascular disease (CVD) (1.07%; 95% CI: 0.30 to 1.81%). The excess risk of hospitalization from CVD is attributable to per 10 µgm-3 increase of average PM2.5 concentration of current and past 3 days increase with age. In contrast, younger people (age<30) have the highest increments in respiratory hospitalization for a 10 µgm-3 increase of 4 days average PM2.5 concentration. For all health outcomes, males have more excess risk than females. In conclusion, this nationwide inquiry furnished robust evidence of the links between short-term exposure to PM2.5 and heightened hospital admissions from various cardiovascular and respiratory morbidities in Bangladesh.