People living in 17 provinces in the North and Bangkok will continue to experience haze pollution until the middle of next week, according to the Pollution Control Department (PCD).
PCD chief Pinsak Suraswadi said on Thursday that all parts of Thailand, except the southern region, are now facing poor air quality caused by hazardous ultra-fine dust particles (PM2.5), which is impacting people's health.
The department found the level of PM2.5 had reached 43-119 microgrammes per cubic metre (µg/m3) in the North, 57-158 µg/m3 in the Northeast, 48-110 µg/m3 in the Central and Western regions, and 62-139 µg/m3 in Bangkok. Levels above 50 µg/m3 are considered unsafe.
Mr Pinsak said the department projected that the haze pollution in the North and the capital would reach a moderate level on Feb 5-6 and fall back within safe levels on Feb 7-8.
He said 1,200 hotspots were detected countrywide yesterday in forest and farming areas. More have been found in neighbouring countries, including 1,713 in Cambodia, 1,072 in Myanmar, 927 in Laos, 522 in Vietnam and four in Malaysia.
Low pressure in the cold season and more traffic are also key factors behind the increasing levels of dust. In contrast, industrial dust only accounts for 10% of the overall volume in the capital.
Mr Pinsak said all 17 governors in the North have been holding daily meetings to provide updates on the situation and find best practices to reduce the number of hotspots while the Ministry of Natural Resources and Environment has been ordered to establish a frontline unit to deal with forest fires.
Farmers who want to burn their fields must get approval from local authorities beforehand.
"The haze pollution this year will be worse than last year as a result of the El Nino phenomenon, which has led to extreme temperature rises with little rainfall, so we can expect more droughts this year. But we will try our best not to make the situation worse than last year by limiting the number of hotspots. This is an urgent priority," Mr Pinsak said.
He suggested working from home is recommended for both state agencies and private companies to reduce people's exposure to toxic air. He also advised people to wear masks because these can reduce the amount of harmful particles inhaled by 50%.
Mr Pinsak said schools should be closed if the average level of ultra-fine dust particles rises above 75 µg/m3. In a bid to protect people's health, the department will reduce the safe level of PM 2.5 to 37.5 µg/m3 from June 1.
Meanwhile, City Hall is urging employers across Bangkok to allow people to work from home today while ordering 69 public health service centres to give out face masks.