People were advised to wear masks when going outside as fine dust again exceeded safety standards on Wednesday at 43 air-quality monitoring stations in Bangkok and surrounding provinces.
Pollution Control Department (PCD) director-general Pralong Damrongthai, said levels of particulate matter of 2.5 microns and less in diameter (PM2.5) stood at 34-87 microgrammes per cubic metre of air in greater Bangkok.
The so-called safe threshold is set at 50 μg/m³.
The affected areas in Bangkok were in the Hiranrujee area of Thon Buri district; Kanchanaphisek Road in Bang Khun Thian district; Bang Na in Bang Na district; Chong Nonsi in Yannawa district; Rama IV Road in Pathumwan district; and Intharapithak Road in Thon Buri district.
Affected areas in surrounding provinces were tambon Nakhon Pathom in Muang district of Nakhon Pathom; Bang Kruai and Pak Kret districts of Nonthaburi; tambon Song Khanong and tambon Talat in Phra Pradaeng district and tambon Bang Phong and tambon Pak Nam in Muang district of Samut Prakan; and Krathumbaen and Muang districts of Samut Sakhon.
Pralong: Warns on fine dust levels
The PCD chief said unsafe levels of dust were also reported in parts of other provinces -- Phra Nakhon Si Ayutthaya district of Ayutthaya province; Muang and Chalerm Prakiat districts of Saraburi; and Muang district of Nakhon Sawan.
He said the Public Health Ministry advised people in risk groups such as children, pregnant women and the elderly to avoid outdoor activities.
People in affected areas should wear masks when outdoors. Earlier this week smog level readings were up to 57 μg/m³.