The Pollution Control Department reported that PM2.5 – particles of dust less than 2.5 micrometres in diameter – in Mae Hong Son's Muang and Pai districts reached 90 micrograms per cubic metre of air (μg/m3) and 105μg/m3, respectively.
Thailand’s safety limit is 50 μg/m3. High levels of PM2.5 pose health risks, especially for people with chronic lung disease.
"Forest fires were spotted in 173 areas across the province on Saturday compared to 98 areas on Friday," the department said.
The department said forest fires occurred around Muang district, especially in the mountain range on the western side of Wat Phra That Doi Kong Mu.
"Fire-fighters have been deployed to extinguish forest fires, especially in areas near communities," it said.
The department added that forest fires were found in 806 areas across Mae Hong Son from January 1 to February 11, with 252 occurring in Pai district alone.
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