Haze pollution in the North resumed on Sunday when levels of levels of cancer-causing PM2.5 dust soared in Chiang Rai and several other northern provinces.
The Pollution Control Department found Chiang Rai's Maung district had the highest level of PM2.5 with 105 microgrammes per cubic metre (µg/m³), followed by 90 µg/m³ in Phayao, 86 µg/m³ in Lampang and 73 µg/m³ in Chiang Mai province.
The amount has been surging in the past last two days due to a number of forest fires starting. Figures show there were 132 hotspots in the North, more than half in Chiang Rai province.
Provinces in the north now face a crisis of haze pollution, which has dominated the province for almost two months as farmers light fires to clear forest land for plantation ahead of the coming rainy season.
Despite warnings of arrest, the situation seems unimproved.
Chiang Rai province is the hardest-hit province in the north.
The highest level of PM2.5 since March 22 was measured at 305 µg./m³ at the end of last month.
The Ministry of Natural Resources and Environment will meet this week to discuss measures to fix the problem.
Meanwhile, the Department of Royal Rain-Making and Agricultural Aviation is preparing to create artificial rain in the North to alleviate the air pollution, after deeming the situation serious enough to use the expensive technology, especially in Chiang Mai.