The PM2.5 Crisis: Chiang Mai's Battle Against Air Pollution.

Chiang Mai, Thailand, has become the world's most polluted city due to hazardous levels of smog caused by field burning during the dry season. The government's focus on addressing symptoms, such as spraying water and seeding clouds, has been ineffective. The root cause lies in contract farming, which pressures smallholder farmers to maximise output through field burning. The government is reluctant to confront the powerful agribusiness conglomerates that are political backers. The public is numb to the issue, and politicians are not campaigning on environmental issues.