Chiang mai: Chiang Mai was ranked the world’s most polluted city on Monday as toxic haze from over 600 wildfires blanketed the region, forcing authorities to deploy helicopters for aerial water drops in mountainous areas.

According to Thai News Agency, satellite imagery confirmed hundreds of “hotspots” across Northern Thailand and neighboring borders, with smoke drifting into urban centers and reducing visibility to a thick white mist.

“I’ve been hospitalized before with lung spots from this dust,” said Natcha Utamang, a resident of Doi Saket who now uses three air purifiers at home. “The impact is devastating; those starting the fires must stop.”

Health officials have advised all residents to wear N95 masks and remain indoors as the seasonal “burning season” continues to deteriorate air quality across the province.

As of 10:00 a.m. today, Chiang Mai’s municipal area was ranked the world’s most polluted city by IQAir, recording a hazardous 263 US AQI and 188 micrograms per cubic meter.