For several months, PM2.5 dust has exceeded 50 microgrammes per cubic metre (µg/m³) in many provinces in Thailand, which is considered unsafe. In some areas, such as Chiang Mai, Chiang Rai and Mae Hong Son, PM2.5 levels have reached over 500µg/m³. While some people are aware of the dangers of PM2.5 pollution, others do not take it seriously.
At the online forum, "PM2.5 Hazard Dust Crisis", recently organised by Chiang Mai University (CMU), Assoc Prof Dr Chalerm Liwsrisakun, head of the Department of the Faculty of Medicine at CMU, expressed surprise at seeing people without masks outdoors despite the negative health effects of PM2.5 being over 200-300µg/m³. Assoc Prof Dr Chalerm also presented a photo of a runner who suddenly collapsed after participating in a competition held on a day with high levels of PM2.5 pollution. He pointed out that PM2.5 pollution can affect the cardiovascular system.
