The Pollution Control Department has warned the level of hazardous dust particles will remain high in greater Bangkok on Monday and Tuesday, trapped by stagnant air, and called for strict enforcement of dust and smoke regulations.
Without wind, fine particulate matter with a diameter of less than 2.5 micrometres (PM2.5) exceeded the safe level of 50 microgrammes per cubic metre of air in many areas of greater Bangkok on Monday morning.
The PM2.5 measured 60-81mcg on the streets and 49-79mcg away from main roads.
The worst areas were Kanchanaphisek Road in Bang Khunthian district, Bang Na sub-district in Bang Na district, Khlongjan sub-district in Bang Kapi district, Din Daeng sub-district and Din Daeng Road in Din Daeng district, Rama IV Road in Pathumwan district, Intarapitak Road in Thon Buri district, and Lat Phrao Road and Phlab Phla sub-district in Wang Thong Lang district.
Hazardous dust levels were also reported in tambon Nakhon Phathom of Muang district in Nakhon Pathom province and tambon Bang Kruai in Bang Kruai district of Nonthaburi.
In Pathum Thani province, tambon Khlong Nueng of Khlong Luang district was worst affected.
In Samut Prakan province, tambon Song Khanong and tambon Talad of Phra Pradaeng district, tambon Pak Nam of Muang district, and tambon Bang Sao Thong in Bang Sao Thong district were worst affected.
In Samut Sakhon province, hazardous dust levels were on frontage roads along Rama II Road in Muang district.
The Pollution Control Department asked authorities to be strict in ordering vehicles emitting black smoke off the roads and to prevent people lighting fires outdoors, and asked motorists to reduce their use of private vehicles.
The Bangkok Metropolitan Administration planned to discuss rainmaking to settle the dust and alleviate the weather conditions.