Chiang Mai municipality was ranked the worst among polluted major global cities on Monday, leaving its peers in the dust as the northern province continues to be battered by forest and man-made fires.
IQAir, a Swiss firm tracking pollutants, reported the Air Quality Index (AQI) in the northern city at 263, a level marked "very unhealthy", as of 10am on Monday. The level of PM2.5 pollutants was measured at 188.0 microgrammes per cubic metre.
The situation in Chiang Mai was far worse than the second most-polluted city, Delhi, whose AQI was only 198 and PM2.5 was 122.0.
Extremely smoggy conditions in Chiang Mai were forecast to continue until around 4pm on Monday, and were then expected to improve throughout the rest of the day and at least until Wednesday.
Chiang Mai province also led the nation in the number of hot spots, at 480 on Sunday, almost doubling from 247 spots in neighbouring Mae Hong Son, according to the Department of National Parks, Wildlife and Plant Conservation. Hot spots are due to natural bushfires in the dry season, burning-off by farmers and the activities of firebugs.
The hot-spots situation remains despite repeated legal warnings from authorities against burning-off and otherwise setting fires. Department director-general Atthaphon Charoenchansa on Sunday admitted the number of hot spots in the country was worrying.
He warned that starting a fire in a state-protected area could result in a fine of 400,000 to 2 million baht and/or 4 to 20 years in prison.
The Chiang Mai-based Environmental and Pollution Control Office responsible for the northern region on Monday warned people in at least 12 areas of Chiang Mai and three neighbouring provinces of the severe danger from small polluted particles that have been accumulating in the air since Wednesday.
Karin Hirunkrailas, chief of the Wildlife Convervation Sanctuary in Omkoi district in Chiang Mai, said on Monday rangers had seized the carcasses of five protected animals from poachers encountered during a fire-fighting patrol in the forest.
The two hunters fled after spotting the patrol, leaving behind two sacks holding the dead animals, a motorcycle, first-aid gear and other evidence.
The evidence pointed to one of the men being named Somkid and living in Doi Tao district in Chiang Mai, Mr Karin said. The park had registered a complaint with police, asking that they find the poachers and press charges.