Air pollution monitoring in the city of Kandy: Possible transboundary effects

Abstract

The city of Kandy, which is situated in a valley between two mountain ranges, is expected to have a high degree of air pollution owing to its geographic location and the ever-increasing numbers of motor vehicles entering the city. The concentrations of three criteria pollutants; nitrogen dioxide, sulphur dioxide and ozone were measured weekly, using samples collected at two loca tions in the city of Kandy and another location outside the city in a rural area. Passive sampling method was used to analyze these pollutants. Weekly samples were continuously collected from each station. In the laboratory, sorbent filter was analyzed for the pol lutants using colorimetric and turbidimetric methods. The data revealed that the concentrations of nitrogen dioxide, sulphur diox ide and ozone during the sampling period exceeded the permitted Sri Lankan standards for ambient air quality on 14%, 41% and 28% occasions respectively. The values obtained were affected by ex ternal conditions such as rainfall, temperature and bright sun shine. A significant effect on transboundary pollution was recorded during the sampling period.