Angry residents protested urging the government to address the 'disaster zone' air pollution in northern Thailand.

More than 200 demonstrators gathered at the square in front of the Mae Sai District Office in Chiang Rai province on March 27, demanding a solution to the forest fires and border pollution plaguing the country's northern region.

Protesters pushed authorities to bring up the problem within the ASEAN political sphere and also called on the private agricultural sector to crack down on illegal agricultural burning - the source of wildfires and smog.

They said the PM2.5 pollution this year was the worst in Thailand since 2011, and they have submitted a letter to Mae Sai District Chief Narongpol Kid-an calling for immediate action.

Mae Sai resident Somyot Nittayaroj said the locals have been experiencing significant air pollution for the past two to three years, and they are demanding a permanent solution from the government to avoid having future protests.

He added that the current haze in Mae Sai has made it challenging for residents, including children and the elderly, to live comfortably.

Pakaimas Vierra, Vice President of the Chiang Rai Chamber of Commerce, said an investigation should be carried out to determine if the illegal burning is happening in Thailand or in neighbouring countries.

She also urged the government to educate farmers to clear their land without resorting to slash-and-burn practices.

Sawetyont Srisamut, another Vice President of the Chiang Rai Chamber of Commerce, said that air pollution is an annual issue, but this year's smog is particularly severe.

He stressed the urgent need for a solution, given the accessibility of data on forest fires and hotspots that were previously unavailable.

He said the Thai government should negotiate with neighbouring countries to address agricultural burning.

Scientists found that smog is at its worst in the country when farmers burn waste crops to cheaply clear their land between late October and April. This is combined with high numbers of polluting cars on the road and large construction projects across the capital.

The seasonal lack of wind and rain, combined with a winter low-pressure system in which cold air is trapped closer to the ground by warm air above – prevent the pollution from being dispersed naturally.

The Thai government has been criticised for failing to tackle the country's air pollution crisis, with bizarre measures such as spraying water into the air and giant purifiers having no impact.

Data scientist engineer Worasom Kundhikanjana said: 'PM 2.5 pollution has a seasonal trend in Bangkok and the northern provinces, but has only recently received public attention. During this winter haze, the harmful particle pollution level is high throughout the day, including on weekends.

'Unfortunately, spraying water into the air does not appear to be effective, since the volume of water is minuscule compared to actual rain.

'With the start of the monsoon season, the weather in Bangkok will get better, and public attention on this issue will likely fade. However, without immediate policy measures, the problem will come back again next winter.'