Spatiotemporal patterns and hot spots of PM2.5 in Bangladesh

Abstract

Urban areas in Bangladesh have seen alarming levels of particulate matter for an extended period, posing serious threats to public health and economic stability. Particulate matter with a diameter of 2.5 μm or smaller, known as PM2.5, can be inhaled by humans and cause serious respiratory and cardiovascular health problems. This study revealed spatial and temporal patterns, seasonal and regional variations, hot spots, and cold spots of PM2.5 in Bangladesh. In addition, the relationship between PM2.5 and meteorological variables was investigated. The results indicate a positive spatial autocorrelation in PM2.5 concentrations, with recent hot spots primarily clustered in the Dhaka, and western parts of the Chittagong divisions. In contrast, cold spots are observed in the Sylhet, Rangpur, and eastern parts of the Chittagong divisions. Seasonal variations revealed notably high PM2.5 concentrations during the winter season. Furthermore, annual average PM2.5 concentrations showed increasing trends for most divisions in Bangladesh, particularly elevated concentrations in Dhaka, Barisal, Khulna, and Chittagong. Overall, this study provides a comprehensive analysis of PM2.5 spatial distributions, clusters, and temporal patterns contributing to understanding the variation and distribution of PM2.5 concentrations across Bangladesh. The findings of this study can be applied to urban planning by prioritizing areas for new air quality monitoring stations, directing efforts to reduce pollution in hot spot areas, and formulating long-term, source-specific policies to improve air quality and public health.