THOUSANDS of people in Chiang Mai province have developed symptoms this month that can be linked to air pollution.
Air-quality tests yesterday also confirmed that pollutants in the northern province had hit unhealthy levels.
Conducted by the Chiang Mai University, the tests showed the amount of small dust particles measuring less than 10 microns in diameter (PM10) had gone past the safe limit of 120 micrograms per cubic metre of air.
Tests conducted at four spots reported the PM10 amount ranging between 131 and 163 cubic metres of air. Smog was clearly visible again |yesterday.
Authorities have now asked people to wear facial masks while going outdoors.
From April 3 to 9, a disease-control office found 447 patients had inflamed eyes, while 8,747 had heart or blood-|vessel problems, 4,638 had respiratory disorders, and 539 had skin issues.