Smog continues to cloak the upper northern region with PM2.5 dust at red-coded levels, and the worst pollution in Mae Hong Son province.
The Pollution Control Department reported that the levels of particulate matter 2.5 micrometres and less in diameter (PM2.5) ranged from 107 to 310 microgrammes per cubic metre of air over the past 24 hours as of 2pm on Tuesday.
