Dangerous levels of thick smog are still blanketing the northern provinces of Chiang Mai, Chiang Rai, and Mae Hong Son, the Pollution Control Department said yesterday.
The levels of particulate matter PM2.5 ranged between 32-241 microgrammes per cubic metre in the North yesterday. The government has set 50µg/m³, far higher than the international standard, as the safe level of PM2.5.
A red alert signifying severe air pollution was issued for the three provinces. In tambon Wiang Phang Kham of Mae Sai district in Chaing Rai, PM2.5 was measured at 108µg/m³. In Chiang Mai, PM2.5 reached 101µg/m³ in tambon Chiang Phuak of Muang district, 100µg/m³ in tambon Sri Phum of Muang district, and 241µg/m³ in tambon Muang Khong of Chiang Dao district. In Mae Hong Son, the PM2.5 level reached 121µg/m³ in tambon Chong Kham of Muang district.
Meanwhile, lower -- but still unsafe -- levels of fine dust were also reported in Mae Chaem, Chalerm Phrakiat district of Nan, Mae Sot district of Tak, and the Muang districts of Chiang Mai, Mae Mo, Lampang, Lamphun, and Phayao.
In the North, air quality was deemed good in the Muang districts of Uthai Thani (32µg/m³), Wichian Buri district of Phetchabun (36µg/m³) and Muang district of Nakhon Sawan (37µg/m³). PM2.5 levels ranged between 44-48µg/m³ in Kamphaeng Phet, Phichit, Phitsanulok and Uttaradit provinces.