Reports of PM2.5 pollution vary widely as Chiang Mai under deep smog
Chiang Mai citizens were left in a pollution haze Thursday as sources released contradictory reports of particulate-based air pollution. One international source reported dangerous levels of particulate matter smaller than 2.5 microns (PM2.5) while a Thai government report shared much lower, yet still very high, readings.
According to an air quality report from the International Air Quality Monitoring website http://aqicn.org/city/chiang-mai/, the level of PM2.5 in Chiang Mai reached the “very unhealthy” level of 203 micrograms per one cubic metre of air as of Thursday morning.
In contrast, data from Thailand’s Pollution Control Department (PCD) air quality monitoring station in Chaing Mai showed that the PM2.5 rose to 110.72 micrograms per one cubic metre of air.
The PCD considers 50 micrograms to be the safe limit, while the World Health Organisation sets the limit at 25 micrograms.
The dense smog was reported throughout Chiang Mai with resulting lowered visibility. It was reported that Doi Su Thep Mountain could no longer be seen from Chiang Mai’s Downtown.
The dense smog also reduced visibility at Chiang Mai Airport, as planes could not be seen in the distance, but the air traffic was not disrupted.
The government’s official Air Quality Index (AQI), as measured by the PCD, showed that the air quality throughout the North, including Chiang Mai, was still within the safe level. The PCD does not include PM2.5 levels in its AQI calculation, despite comments by experts encouraging it to do so.
