Fine dust levels were rising again in greater Bangkok but still on the safe side on Wednesday, but people in the northern provinces were still smogged-in.
The Pollution Control Department reported that levels of particulate matter 2.5 micrometres and less in diameter (PM2.5) ranged from 16 to 43 microgrammes per cubic metre of air in greater Bangkok over the past 24 hours as of Wednesday morning. The government-set safe threshold is 50 mcg/cu m.
The lowest level was reported in Klong Chan sub-district of Bang Kapi district in Bangkok.
The department said PM2.5 levels rose due to traffic congestion on Tuesday evening and Wednesday morning, with only light winds. It expected stronger winds would clear the air on Wednesday afternoon.
In other provinces, PM2.5 levels ranged from 6-109 mcg/cu m. The lowest level was in Muang district of the northeastern province of Mukdahan, and the highest in tambon Na Chak of Muang district in the northern province of Phrae.
Unsafe pollution was reported in Muang district of Kanchanaburi; Mae Sot district of Tak; Chalerm Prakiat and Muang districts of Nan; Phra Nakhon Si Ayutthaya district of Ayutthaya; Muang district of Phayao; Mae Mo and Muang districts of Lampang; Chalerm Prakiat district of Saraburi; and Muang district of Suphan Buri.