Sixty-four out of 77 provinces in Thailand were shrouded with unsafe levels of ultrafine dust pollution on Sunday morning, according to the Geo-Informatics and Space Technology Development Agency (Gistda).
Seventeen provinces recorded red levels (hazardous to health) of particulate matter 2.5 micrometres and less in diameter (PM2.5), Gistda reported at 7am on Sunday.
Sing Buri faced the highest red level of PM2.5 at 95.5 microgrammes per cubic metre of air over the past 24 hours.
It was followed by Si Sa Ket (91.2µg/m³), Yasothon (85.3), Ubon Ratchathani (84.6), Trat (84.2), Lop Buri (83.9), Saraburi (82.1), Ang Thong (80.4), Kalasin (80.1), Roi Et (79.6), Surin (78.1), Chai Nat (78), Chachoengsao (75.7), Nong Khai (75.6), Samut Songkhram (75.4), Nakhon Phanom, (75.3) and Nong Bua Lam Phu (75.2).
The safe threshold is 37.5µg/m³.
Thirteen provinces had safe air quality. Nine provinces had moderate air quality represented by yellow levels of PM2.5 ranging from 25.2 to 36.6. In descending order, they were Phangnga, Nakhon Si Thammarat, Ranong, Surat Thani, Chumphon, Phrae, Phayao, Krabi and Chiang Rai.
Good air quality was detected only in Lampang (24) and Mae Hong Son (18.4).
Very good air was in Chiang Mai (14.9) and Lamphun (13.7).
Forty-seven other provinces faced orange levels (starting to affect health) of PM2.5 ranging from 41.5 to 74.7. They included Ayutthaya, Bangkok, Nan, Prachuap Khiri Khan, Phuket and Samut Prakan.
The map from Gistda shows thick smog, represented with red and orange colours, in the Central Plain, the Northeast and the East on Sunday morning.
