Chiang Mai air pollution hits above safety level
Chiang Mai province was hit by unprecedented levels of air pollution on Wednesday as intensifying forest fires sent PM2.5 levels in some areas up to 592 microgrammes per cubic metre (ug/m3) of air, almost 12 times above safe levels. The level of PM2.5 — fine dust that can get lodged in lungs and cause coronary disease — rose to 592 …