Air pollution has become a serious environmental and health issue in Thailand. The pollution levels in the country follow predictable patterns, which highlight the presence of a peak pollution season. For Bangkok, the highest levels of pollution are seen between November and February each year.
The first step in any effort to mitigate air pollution is to understand the magnitude of the problem and the sources of pollution. The most common measure of air quality is the Air Quality Index (AQI). The AQI is based on measurement of particulate matter (PM2.5 and PM10), Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2) and Carbon Monoxide (CO) emissions. Using a composite index of air quality as the AQI is extremely important in understanding the magnitude of the problem. To go a step further and design mitigation actions someone has to perform more detailed analysis and “decipher” the meaning of a single numerical measure in order to identify the sources of pollution.
A hazy Bangkok skyline – or an invisible city skyline – is the most evident indication of air pollution, as small particles, generally referred to as particulate matter of 10 or 2.5 microns in width, are suspended in the air. Of these two sets of particles the PM2.5 draw big attention because of their high contribution to air pollution and the detrimental health effects they can cause in our respiratory systems. Although these small particles are measured by size, there are significant differences in their chemical composition depending on their origin. By analyzing this chemical fingerprint, we can determine the cause of pollution as well as different toxicity factors and health impacts of the PM2.5 particles.