Vehicular exhaust, accumulated since Friday evening when traffic was the worst of the week, compounded by a temperature inversion increased air pollution in and around Bangkok on Saturday, according to the Pollution Control Department.
It said, however, that the problem eased somewhat during the afternoon as airborne dust was dispersed by the onset of a south-easterly 10-20kph breeze.
Seven areas in Bangkok and six in surrounding areas were found to have excessive PM2.5 dust particles of up to 66 microns this morning, but pollution in some northern and north-eastern provinces today is worse than in Bangkok, mainly due to smoke from forest fires and the burning of farm waste.
The levels of PM2.5 dust in Mae Sot district of Tak, Muang and Mae Moh districts of Lampang and Muang district of Phrae in the North were measured at 27-77 microns.
In Muang district of Khon Kaen, Muang district of Nakhon Ratchasima and Muang district of Loei in the north-east, the levels of PM2.5 were measured at 58-80 microns.
The levels were measured at 58-83 microns in Muang district of Kanchanaburi, Muang district of Nakhon Sawan, Muang district of Ayutthaya, Muang district of Ratchaburi, Muang district of Saraburi and Muang district of Suphan Buri in the central and western regions.
The Meteorological Department, meanwhile, reported that a moderate cold front will blanket north-eastern Thailand and the South China Sea tomorrow.
Temperatures in the north-east will rise slightly as the moderate cold front moves eastward into the South China Sea, and this will cause isolated thunderstorms in the eastern and central regions from January 22nd to 24th.
