Preliminary assessment of outdoor and indoor air quality in Yangon city, Myanmar

Abstract

Air pollution related problems in urban areas of developing countries get bigger quickly. Yangon is the most urbanized and most densely populated city in Myanmar. Information on air quality of Yangon is still lacking. Therefore, we conducted this study for initial assessment of outdoor and indoor air quality of Yangon. Four kinds of diffusive air samplers were used to measure volatile organic compounds (VOCs), ozone and carbonyl compounds, acidic gases and ammonia. As a result of this study, higher alkanes were found dominant among outdoor VOCs. Benzene/toluene ratios ranged from 0.15 to 0.53. Formaldehyde/acetaldehyde ratios varied from 1.5 to 2.4. Maximum outdoor ozone value was 26 μgm−3. A strong negative correlation between outdoor ozone and nitrogen dioxide concentrations was noted. Compared with previous local studies, outdoor nitrogen dioxide and sulfur dioxide concentrations were found to be on the increasing trend. The indoor/outdoor ratios at some sites revealed that there were indoor sources for α-pinene, d-limonene, p-dichlorobenzene and methyl isobutyl ketone. The ratios of pollutants with outdoor sources mostly ranged between 1 and 2. In conclusions, although it is a preliminary assessment, the findings can provide invaluable information towards comprehensive picture of air quality of Yangon. Outdoor air quality is found contaminated with pollutants most of which are traffic-related indicating that the city is now facing high traffic volume greater than before. Indoor air quality is varied with indoor characteristics of the buildings. Gases with health concern are identified in indoor air. Inadequate ventilation may precipitate poor indoor air quality.