Provincial governors in the North are being urged to step up measures against open-air burning after PM 2.5 pollutants reached hazardous levels for almost a week.
Pralong Damrongthai, director-general of the Pollution Control Department (PCD), said the Interior Ministry has been roped in to prevent the haze situation in the northern region from worsening. He said forest fires are to blame for poor air quality in nine provinces.
The Ministry of Natural Resources and Environment is asking provincial authorities to strictly control burning of rubbish, farm waste and clearing of scrubland to reduce haze in the region.
Mr Pralong said other efforts are also being made to reduce the level of dust, such as spraying water in urban areas. The PCD is also working with the provincial and local authorities in raising public awareness of the health hazards of haze.
"We're asking people to refrain from burning activities to prevent the dust levels from rising," he said.
He stressed that villagers need to wear face masks when venturing outside their homes and visiting areas where the hazardous dust levels are high, adding that vulnerable groups are strongly advised to stay inside.
As of Friday, the PM2.5 readings in the North stood at 76-202 microgrammes per cubic metre of air. The worst air quality was in Chiang Rai where the air quality index (AQI) in tambon Wiang Phang Kham in Chiang Rai's Mae Sai stood at 302.
The AQI measures a broad spectrum of air pollutants including PM2.5, PM10 and carbon dioxide.
The unhealthily high levels of smog was also reported in several areas including tambon Mae Pa in Mae Sot district of Tak, tambon Nai Wiang in Muang district of Nan, tambon Ban Tom in Muang district of Phayao, tambon Phra Bat in Muang district of Lampang and tambon Na Chak in Muang district of Phrae.
The provincial governors insisted that the ban on burning activity would be enforced strictly.
The haze situation has taken its toll on the tourism sector in several provinces.
The number of visitors to Tham Luang cave complex in Chiang Rai's Mae Sai district has reportedly decreased by half from around 3,000-4,000 daily to 1,500 following reports about the haze, according to local officials.
Meanwhile, the Professional Golf Association of Thailand announced on its website that a golf event scheduled on March 21-22 in Lamphun will be postponed indefinitely due to the dangerously high levels of PM2.5.