This paper reports on a study carried out to examine human exposure to street-level air pollutants in Sri Lanka and explores the effectiveness of mitigation options. Baseline air pollution and health risk assessment data were collated and a free-ware computer model (Envi-met) was then applied to a selected urban area to test the effectiveness of air pollution mitigation options. Model variables included changes to street vegetation, soil conditions and building geometry. Background aerosol (particulate matter, sulfur dioxide and nitrogen dioxide) exposure was found to be significantly different for urban and rural populations. More greenery and reduced vehicular traffic on roads entering main traffic arteries resulted in a decreased particulate matter concentration, whereas the presence of high-rise buildings resulted in an increase. On the basis of the research findings, the paper suggests a 'best case' with a marked decrease in particulate matter concentration compared with the current situation. The possibility of using this methodology in the schematic planning stages of new developments and the regeneration of existing neighbourhoods is highlighted.