Influence of Urbanization on Particulate Matter Pollution in Coimbatore City, India

The spatial-temporal distribution of air pollutants over India’s growing cities is still uncertain due to the lack of monitoring data and inadequate knowledge. This study analyzes the temporal and spatial trends of particulate matter in Coimbatore and furthers the influence of urban growth on aerosol concentrations also investigated. The average concentration of PM2.5 and PM10 was 42.23 and 68.05 µg m-3 during the study period and slightly higher than the National Ambient Air Quality Standards. Aerosol concentrations were found to be highest in an industrial site (81.17 µg m-3 for PM10 and 51.89 µg m-3 for PM2.5), medium in urbanindustrial (69.09 µg m-3 for PM10 and 42.53 µg m-3 for PM2.5), commercial (69.99 µg m-3 for PM10 and 42.31 µg m-3 for PM2.5), residential (68.39 µg m-3 for PM10 and 41.21 µg m-3 for PM2.5) sites, and low in the mixed site (51.59 µg m-3 for PM10 and 33.19 µg m-3 for PM2.5). Geographic Information System analysis results indicate that Coimbatore city became more urbanized and more polluted than before. PM2.5/PM10 ratio of 0.60-0.65 in the respective locations revealed the dominance of PM2.5. Vehicular exhaust emissions and road dust resuspension are the primary sources of air quality deterioration in Coimbatore city since there are no other significant pollution sources. Our findings provide baseline information concerning the influence of urbanization and transportation on particulate matter pollution in Coimbatore city.