The unsafe levels of ultrafine dust were detected in the North, the Northeast and parts of other regions over the past 24 hours, according to the Geo-Informatics and Space Technology Development Agency (Gistda).
Gistda reported at 7am that 43 provinces were blanketed with unsafe levels of particulate matter 2.5 micrometres and less in diameter (PM2.5) and red (hazardous-to-health levels of the dust were detected in 18 northern and northeastern provinces. The government-set safe level is at 37.5 microgrammes per cubic metre of air in 24 hours.
The highest level, 154.8µg/m³, was measured in Bueng Kan, followed by 138.9 in Nakhon Phanom, 114.2 in Nong Khai and 101.4 in Sakon Nakhon. All these provinces are in the Northeast.
People in 14 other provinces also faced red levels of PM2.5 from 75.9 to 92.2µg/m³.
In descending order of the dust levels, they were Loei, Mukdahan, Nan, Udon Thani, Lamphun, Phayao, Kalasin, Amnat Charoen, Ubon Ratchathani, Nong Bua Lam Phu, Lampang, Phrae, Mae Hong Son and Yasothon.
Orange levels of PM2.5 (starting to affect health) were reported from 39.1 to 73.3µg/m³ in 25 provinces.
In descending order, they were Chiang Rai, Sukhothai, Maha Sarakham, Khon Kaen, Roi Et, Uttaradit, Chiang Mai, Phitsanulok, Tak, Si Sa Ket, Phetchabun, Chaiyaphum, Surin, Kamphaeng Phet, Phichit, Buri Ram, Nakhon Ratchasima, Phuket, Trat, Nakhon Sawan, Uthai Thani, Satun, Kanchanaburi, Chai Nat and Lop Buri.
Moderate air quality with PM2.5 levels from 26.4 to 36.5µg/m³ were recorded in Bangkok and 32 provinces including Ayutthaya, Chumphon, Krabi, Nakhon Pathom, Phangnga, Phetchaburi, Prachuap Khiri Khan, Songkhla and Surat Thani.
At 7am, Samut Prakan was the only one province of good air quality with the PM2.5 level of 24.9µg/m³.
The Gistda map shows unsafe levels of PM2.5 in red and orange in the North and the Northeast on Wednesday morning.
