The photos were taken from the30th Anniversary Building at Chiang Mai University’s Engineering Faculty. The PCD’s method of basing their numbers on averaging the 24-hour levels, resulted in their reporting lower levels of pollution when compared to the real-time basis reports from other sources, such as the Chiang Mai University mobile “Dust Boy” devices and the Chiang Mai Air Quality Health Index (CMAQHI) Centre. Chiang Mai’s Muang district station cited 77 micrograms of PM2.5 and an AQI level of 168. Hang Dong district had 99 micrograms of PM2.5 and an AQI level of 173, while Muang district had 73 micrograms and an AQI level of 160, the centre reported. Chiang Mai provincial authority announced imposition of a 60-day outdoor-burning ban from March 1 to April 30.

Source: The Nation Bangkok February 12, 2019 08:11 UTC