Unsafe levels of toxic ultrafine dust were detected in 58 out of 77 provinces in Thailand, with the worst air pollution detected in the Central Plain on Sunday morning.
The Geo-Informatics and Space Technology Development Agency (Gistda) reported at 10am that particulate matter 2.5 micrometres and less in diameter (PM2.5) was at red (hazardous-to-health) levels in 20 provinces.
The highest level of PM2.5, 109.7 microgrammes per cubic metre of air over the past 24 hours, was recorded in Sing Buri province.
It was followed by 108.5µg/m³ in Chai Nat, 94.4µg/m³ in Lop Buri, 91.2 in Nakhon Sawan, 88.3 in Saraburi, 86 in Uthai Thani and Kamphaeng Phet, 85.9 in Prachin Buri, 83.3 in Khon Kaen, Chaiyaphum and Nong Bua Lam Phu, 82.7 in Chachoengsao, 82.5 in Ang Thong, 81.7 in Phetchabun, 80.9 in Nakhon Ratchasima, 80.5 in Sa Kaeo, 79.5 in Phichit, 77.6 in Sukhothai, 77.4 in Loei and 75.4 in Chon Buri.
The safe threshold is at 37.5µg/m³.
Safe air was reported in 19 provinces, including 10 at yellow levels of PM2.5 ranging from 26.3 to 34.2µg/m³ (moderate air quality). In ascending order, they were Narathiwat, Mae Hong Son, Chiang Mai, Chiang Rai, Sonkhla, Phatthalung, Yala, Pattani, Trat and Lamphun.
Nine others, in the South, had good (green-level) air quality with PM2.5 levels ranging from 15.2 to 24.9µg/m³. In ascending order, they were Krabi, Phuket, Phangnga, Nakhon Si Thammarat, Satun, Surat Thani, Ranong, Chumphon and Trang.
The 38 remaining provinces recorded orange levels (starting to affect health), with PM2.5 ranging from 39.8 to 73.7µg/m³. They included Greater Bangkok.
