PM2.5 spikes in Thailand
Air pollution surged across northern Thailand on April 11, with PM2.5 concentrations rising above safe limits in Chiang Rai and 37 other provinces. The Air Pollution Mitigation Center said the North and Northeast were the hardest hit, warning outdoor activity could be affected (chiangraitimes.com).
Northern Thailand’s air turned hazardous on April 11, with fine-particle pollution rising above Thailand’s safety limit in Chiang Rai and 37 other provinces. (chiangraitimes.com) Thailand’s Air Pollution Mitigation Center said the North and Northeast were the hardest-hit regions, and air-quality maps showed “deep red” conditions in multiple areas on April 11. Bangkok Post reported red-level readings of 92.1 micrograms per cubic metre in Chiang Rai, 85.8 in Phayao, 85.8 in Nan, 83.8 in Phrae, 83.5 in Lampang, and 81.7 in Chiang Mai. (chiangraitimes.com) (bangkokpost.com) PM2.5 means particles smaller than 2.5 micrometres, small enough to get deep into the lungs and enter the bloodstream. Thailand tightened its 24-hour PM2.5 standard to 37.5 micrograms per cubic metre in 2024, while the World Health Organization guideline for 24-hour exposure is 15 micrograms per cubic metre. (eanet.asia) (who.int) The spike followed a surge in fire hotspots, which are heat signatures picked up by satellites and often linked to open burning or wildfires. The Geo-Informatics and Space Technology Development Agency counted 5,277 hotspots in Thailand on April 11, and Bangkok Post said more than 3,000 were in conservation forest areas. (bangkokpost.com) (gistda.or.th) This is Thailand’s annual smoke season, when dry weather, agricultural burning and forest fires combine with weak air circulation to trap pollution over the North. Nation Thailand reported on April 2 that officials were already warning high PM2.5 levels could worsen as ventilation weakened. (nationthailand.com) The problem reaches beyond one province. On April 2, IQAir data cited by Nation Thailand pushed Chiang Mai Municipality to No. 2 among the world’s most polluted cities, showing how quickly northern Thai cities can climb global pollution rankings during the burn season. (nationthailand.com) Real-time monitors showed the air was still unhealthy in Chiang Rai late on April 11. IQAir recorded a United States Air Quality Index reading of 167 and PM2.5 at 79 micrograms per cubic metre at 6 p.m. local time, about 15.8 times the World Health Organization annual guideline. (iqair.com) Thai health authorities have built an emergency response system around these spikes, including provincial public health emergency operations centers and province-by-province reporting. On April 12, the Health Ministry’s PM2.5 dashboard showed 16 provincial emergency centers open. (moph.go.th) For now, the immediate picture is the same one Thailand sees most dry seasons: more fire hotspots on the map, more northern provinces over the limit, and more days when outdoor activity carries a health warning. (chiangraitimes.com) (bangkokpost.com)
