CHIANG MAI, Thailand (AFP) — Thai tourist hotspot Chiang Mai was blanketed by hazy smog Friday, as residents and visitors to the usually picturesque northern city were left wheezing in the toxic air.

The city topped air monitoring website IQAir’s table of the world’s most polluted cities early Friday.

Levels of PM2.5 pollutants — cancer-causing microparticles small enough to enter the bloodstream through the lungs — were classified as “very unhealthy” and hit more than 35 times the World Health Organization’s annual guideline.

“It’s very high. All I have is this mask which is the same one I used for Covid,” orange seller Kamol, 62, told Agence France-Presse at the city’s Warorot Market.

Thailand’s former prime minister Thaksin Shinawatra, who was recently freed early from a jail sentence for graft and abuse of power following 15 years in self-exile, visited the market on Friday, donning a mask while he posed for photos with well-wishers.

High levels of pollution frequently hit Thaksin’s hometown of Chiang Mai during the early months of the year when farmers often burn crops to clear land, and forest fires and exhaust fumes also add to the problem.