By The Nation | 11 April 2019
All nine northern provinces, including Chiang Mai and Chiang Rai, on Thursday morning, cited dangerous levels of PM2.5 – airborne particulates 2.5 microns or less in diameter.
All nine northern provinces, including Chiang Mai and Chiang Rai, on Thursday morning, cited dangerous levels of PM2.5 – airborne particulates 2.5 microns or less in diameter.