CHIANG MAI reported the worst smog this year Tuesday morning with tiny particles at 253 micrograms per cubic metre at an air station near Yupparat Wittayalai School, while a City Hall station recorded 247 mg per cu/m.
The amount of tiny dust in the air was double the safety level of 120 mg per cu/m, and some 2,200 residents were reportedly seeking medical treatment for smog-triggered illnesses.