Eight out of 77 provinces in Thailand were shrouded with slightly unsafe levels of ultrafine dust pollution on Sunday morning, according to the Geo-Informatics and Space Technology Development Agency (Gistda).
All the eight provinces, mostly in the North, were blanketed with orange levels (starting to affect health) of particulate matter 2.5 micrometres and less in diameter (PM2.5) ranging from 38.3 to 48.6 microgrammes per cubic metre of air over the past 24 hours, Gistda reported at 7am.
The government-set safe lervel is 37.5µg/m³.
In descending order, they were Lamphun, Samut Songkhram, Phrae, Lampang, Chiang Mai, Phayao, Nan and Mae Hong Son. Samut Songkhram is in the Central Plain. The other seven provinces are in the North.
Twelve provinces had very good air quality, represented in blue levels of PM2.5 ranging from 8.8 to 15µg/m³.
Most of them are in the Northeast and the South, including Bueng Kan, Nakhon Phanom, Phuket, Sa Kaeo, Satun and Ubon Ratchathani. Bueng Kan had the lowest PM2.5 level at 8.8µg/m³.
Thirty-four province had good air quality including Chon Buri, Greater Bangkok, Krabi, Loei, Nakhon Pathom, Nakhon Ratchasima and Rayong. Their PM2.5 levels were represented in green ranging from 15 to 24.8µg/m³.
The Gistda map on Sunday morning shows low and moderate levels of PM2.5 in blue, green and yellow.
