Toxic Dust Covers Chiang Mai, Ranking 6th Among the World’s Most Polluted Cities
Chiang Mai: The smog still covers Chiang Mai Province densely, with the hourly PM 2.5 dust level at almost 500 micrograms per cubic meter, ranking 6th among the world’s most polluted cities, after more than 2,000 hotspots from burning were found throu…