The highest PSI reading of 191 microgrammes/cubic metre was recorded in Chiang Rai.
The Pollution Control Department’s Air Quality and Noise Management Bureau said today that PM10 dust measurement in five northern provinces returned to unhealthy levels again with PSI recording at over the standard level of 120.
It said PSI recordings for Tambon Wiang of Muang district, Chiang Rai was 191, for Tambon Sriwiang of Muang district Chiang Mai was 123, for Nan was 128, for Tambon Wieng of Muang district, Phayao was 133, and for Tambon Phrabat of Muang district, Lampang was 134.
It warned elderly people, children and patients affected from respiratory sickness in the five provinces to refrain from outdoor activities.
In case they have to leave homes, they are advised to wear dust masks.
(Photo : Thai PBS File)