The Geo-Informatics and Space Technology Development Agency (Gistda) reported at 8am yesterday that 39 provinces were shrouded with “red” hazardous-to-health levels of particulate matter 2.5 micrometres and less in diameter (PM2.5), reports the Bangkok Post.
The Pollution Control Department said that smog accumulated in Greater Bangkok, the lower North and the Northeast due to stagnant air and the condition should be alleviated from this Saturday onward.
The PM2.5 levels ranged from 76.5 to 143.1 microgrammes per cubic metre of air in the 24 hour period from Tuesday to yesterday morning. The highest level was in Samut Sakhon province, followed by 133.2µg/m³ in Pathum Thani, 129.4µg/m³ in Bangkok, 128.6µg/m³ in Nonthaburi and 125µg/m³ in Ayutthaya.
Other provinces facing the red levels of smog, in a descending order, were Nakhon Pathom, Samut Prakan, Ang Thong, Sing Buri, Saraburi, Lop Buri, Samut Songkhram, Ratchaburi, Phetchaburi, Suphan Buri, Chai Nat, Uthai Thani, Nakhon Sawan, Chachoengsao, Nakhon Ratchasima, Kanchanaburi, Chaiyaphum, Prachin Buri, Phetchabun, Phichit, Nakhon Nayok, Sa Kaeo, Maha Sarakham, Chon Buri, Khon Kaen, Kamphaeng Phet, Nong Bua Lam Phu, Nong Khai, Phitsanulok, Udon Thani, Prachuap Khiri Khan, Rayong, Loey and Buri Ram.
The government-set safe threshold is 37.5µg/m³.
Thirty-one provinces were covered with orange levels of PM2.5 which were the levels of ultrafine dust that started to affect health. The levels ranged from 41.7 to 73.4µg/m³.
In a descending order, the provinces were Tak, Kalasin, Chanthaburi, Surin, Sakon Nakhon, Mukdahan, Roi Et, Ubon Ratchathani, Sukhothai, Si Sa Ket, Nakhon Phanom, Phatthalung, Yala, Trang, Pattani, Narathiwat, Satun, Phuket, Songkhla, Yasothon, Amnat Charoen, Uttaradit, Trat, Bueng Kan, Krabi, Nan, Lamphun, Phrae, Nakhon Si Thammarat, Phangnga and Lampang.
Safe PM2.5 levels ranging 21.2 to 36.4µg/m³ were in Phayao, Ranong, Chiang Rai, Surat Thani, Chumphon, Chiang Mai and Mae Hong Son which recorded the lowest level.