Thai PM vows to curb air pollution in tourist hotspot Chiang Mai

The picturesque historic city is hugely popular with visitors but annually suffers dire air quality in the early months of the year when farmers burn crops.

Prime Minister Srettha Thavisin, who is on a four-day northern tour, acknowledged his government needs to tackle the smog.

"Even if the pollution level is lower than last year at this time, we are still concerned and will find solutions to improve the livelihood of the people," he told reporters.

His visit came as Chiang Mai topped air monitoring website IQAir's list of the world's most-polluted cities for the second consecutive day.

Levels of PM 2.5 pollutants -- small enough to enter the bloodstream through the lungs -- were at 224 on Saturday afternoon, 20 times higher than the World Health Organization's guidelines.

Earlier, Srettha visited the Command Centre for Wildfires and PM2.5 Prevention in the city's Mae Taeng district.

After meeting with workers, he told reporters he was working with local authorities to study the impact of transnational haze. He added that he would impose regulations on farmers who burnt stubble, without giving further details.

Earlier this year, Srettha's cabinet approved a Clean Air Act aiming to tackle the issue.

It follows a government body warning this month that more than 10 million patients sought treatment for pollution-related diseases last year in Thailand.

Srettha's visit to Chiang Mai coincided with that of ex-PM and controversial billionaire Thaksin Shinawatra, as well as opposition MP and former Move Forward Party leader Pita Limjaroenrat.

Thaksin -- on his first public outing since his release from a jail sentence following his return from self-exile -- also spoke about PM 2.5, calling it "the biggest problem".