Effects of fine particulate matter air pollution on cardiovascular mortality in Dhaka, Bangladesh, from 2020 to 2024

Although air pollution is a leading cause of mortality in Bangladesh, epidemiological studies remain limited and largely focus on exposure rather than health outcomes. Therefore, we investigated the effects of fine particulate matter (PM 2.5 ) exposure on Cardiovascular Disease (CVD) mortality in Dhaka city. We collected monthly CVD mortality records from four major government medical college hospitals in Dhaka city between 2020 and 2024. We obtained corresponding PM 2.5 concentrations from the Department of Environment and meteorological data from NASA POWER project. We applied a Generalized Additive Model (GAM) with a quasi-Poisson distribution and incorporated lag structures to estimate the percentage change in CVD mortality per 10 µg/m³ increase in PM 2.5 concentration. We found a total of 17,531 CVD deaths during the study period. A 10 µg/m³ increase in PM 2.5 concentration was associated with a 3.1 % increase in CVD mortality at lag 0 (95 % CI: 1.1 % , 5.2 %). Furthermore, an estimated 16 % of total CVD deaths during the study period were attributable to PM 2.5 exposure. Seasonal analysis showed that 28.7 % of CVD deaths in cold months were attributable to PM 2.5 , compared to only 7.15 % during the hot months. The exposure-response relationship was non-linear and showed a gradual increase in CVD mortality, indicating higher health risks at high levels of PM 2.5 . Our study provides clear evidence that elevated PM 2.5 concentrations significantly contribute to cardiovascular mortality in Dhaka city. Therefore, reducing PM 2.5 through urgent and sustained policy action, targeted emission control, and improved monitoring could substantially lower CVD mortality and mitigate the growing health impacts of air pollution in urban Bangladesh.