Toxic haze remains at critical levels across large parts of the country, with PM2.5 concentrations exceeding safety standards in 37 provinces, the Pollution Control Department (PCD) reported on Friday.
The most severe pollution was recorded in Pai district of Mae Hong Son province, while officials warned levels were likely to worsen over the next seven days.
The Centre for Pollution Mitigation Communication under the PCD on Friday reported that nationwide PM2.5 readings ranged from 12.5 to 352.2 microgrammes per cubic metre (µg/m³), far exceeding the safe limit of 37.5 µg/m³.
A total of 37 provinces reported pollution above the standard, spanning much of the North and Northeast.
Affected provinces are Chiang Rai, Chiang Mai, Nan, Mae Hong Son, Phayao, Lamphun, Lampang, Phrae, Uttaradit, Sukhothai, Phitsanulok, Tak, Kamphaeng Phet, Phichit, Phetchabun, Nakhon Sawan, Uthai Thani, Chai Nat, Saraburi, Bueng Kan, Nong Khai, Loei, Udon Thani, Nakhon Phanom, Nong Bua Lam Phu, Sakon Nakhon, Mukdahan, Khon Kaen, Kalasin, Maha Sarakham, Roi Et, Amnat Charoen, Chaiyaphum, Yasothon, Ubon Ratchathani, Si Sa Ket and Surin.
The North recorded the most severe conditions, with readings between 48.5µg/m³ and 352.2µg/m³. The highest level in the country was detected in tambon Wiang Tai of Pai district, Mae Hong Son, at 352.2µg/m³.
In the Northeast, PM2.5 levels ranged from 34.1-102.9µg/m³, also exceeding safe limits in most areas.
The Central Plains and the West reported exceedances in two locations, with levels between 15.8µg/m³ and 40.7 µg/m³.
In the East, air quality remained largely good, with readings between 14.1µg/m³ and 29.0 µg/m³, while the South reported very good conditions, ranging from 13.3-22.2 µg/m³.
Bangkok and surrounding areas also recorded generally good air quality, with levels between 12.5-36.5 µg/m³.
