Trends of Air Pollutants in Colombo City and Relationship with Meteorological Variables

Abstract

Colombo, the commercial capital of Sri Lanka, has to deal with air pollutants such as Sulphur dioxide (SO2), Nitrogen dioxide (NO2), Particulate matter (PM2.5 and PM10). The main objective was to study the trends of NO2 and SO2 concentrations during the period 2013-2019 and predict the future air quality of Colombo by modelling the monthly time series of those pollutants. The data used in this research was secondary, obtained from the National Building Research Organization (NBRO) and the Department of Meteorology of Sri Lanka. The SO2 and NO2 exponential smoothing models fitted had R- squared values of 66.40% and 68.90% respectively. Significant correlation results were obtained between the predicted (2020-2021) and the observed values. The NO2 levels displayed a significant correlation (r = 0.86, p