Assessment of PM10 in Colombo, Sri Lanka and Its Potential Source Regions

Abstract

Air pollution, specifically the presence of particulate matter (PM10) is a growing concern in many parts of the world, including Sri Lanka because of their ability to cause series health risks, destructive environmental damage and their negative effects on the nation’s economy. Since Colombo is the commercial capital of Sri Lanka, this study analyzed the PM10 concentrations in Colombo over one-year period; impact of meteorological parameters on the PM10 levels and potential source regions. To accomplish this, data on 24-hour average PM10 concentrations and meteorological parameters were collected at Colombo from Jan to Dec 2022. Colombo experienced 40.5 ± 26.6µgm-3 average PM10 concentrations in 2022 which is about 3 times higher than WHO guidelines (15µgm-3). Seasonally, Northeast monsoon season experienced the highest average PM10 concentration (~56.8 µgm-3) in Colombo that may be attributed to low rainfall (~3.8mm) and low wind speed (~12.1mph). Conversely, minimum average PM10 level (~24.2 µgm-3) occur during Southwest monsoon which may be caused by higher rainfall (~8.4mm) and wind speed (~17.9mph). CBPF was used to evaluate the potential source regions for high PM10 levels in Colombo, indicating potential sources could be vehicular emission, thermal power plant, waste combustion and industrial emissions. The results of this study assist policy makers in charting the control strategies in the region.