Fine dust levels were above the safe threshold of 50 microgrammes per cubic metre (µg/m³) in 55 provinces, bar the South, on Wednesday morning, the Centre for Air Pollution Mitigation reported.
The 55 provinces with unsafe levels of PM2.5 dust as of 7am on Wednesday were: Bangkok, Pathum Thani, Nonthaburi, Nakhon Pathom, Samut Sakhon, Samut Prakan, Chiang Rai, Chiang Mai, Nan, Mae Hong Son, Phayao, Lamphun, Lampang, Phrae, Uttaradit, Sukhothai, Tak, Phitsanulok, Kamphaeng Phet, Phichit, Phetchabun, Nakhon Sawan, Uthai Thani, Sing Buri, Lop Buri, Saraburi, Ang Thong, Suphan Buri, Ayutthaya, Kanchanaburi, Ratchaburi, Samut Songkhram, Prachuap Khiri Khan, Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri, Rayong, Chanthaburi, Trat, Bung Kan, Nong Khai, Loei, Udon Thani, Nakhon Phanom, Nong Bua Lamphu, Sakon Nakhon, Khon Kaen, Kalasin, Roi-et, Chaiyaphum, Ubon Ratchathani, Si Sa Ket, Nakhon Ratchasima and Buri Ram.
By region, PM2.5 levels were 65-137 µg/m³ in the North, 48-170 µg/m³ in the Northeast, 50-98 µg/m³ in the Central Plains and the West, 59-86 µg/m³ in the East, and 17-33 µg/m³ in the South.
In Bangkok and nearby provinces, the PM2.5 range was 55-131 µg/m³.
Worldwide, as of 9.26am on Wednesday, Chiang Mai was the 5th most polluted major city globally in terms of air quality, with an air quality index (AQI) of 181, according to website www.iqair.com.
Above Chiang Mai were: Baghdad, Iraq with 230 AQI; Lahore, Pakistan with 224 AQI; Dubai, the United Arab Emirates (UAE) with 193 AQI; and Delhi, India with 185 AQI.
