BANGKOK : Thailand's popular tourist destination Chiang Mai was shrouded in unhealthy air on Thursday, with its air quality ranked second worst in the world.
At 12 pm, Chiang Mai's Air Quality Index AQI reading in Chang Phueak subdistrict was recorded at 187 an unhealthy level according to the Air Quality and Noise Management Bureau of Thailand's Pollution Control Department.
The public was advised to watch their health as well as reduce outdoor activities if they have difficulty breathing, eye irritation or coughing.
At-risk individuals should avoid strenuous physical activity, particularly outdoors, and consult doctors if symptoms worsen, said the Air Quality and Noise Management Bureau.
At midday, Chiang Mai's air pollution was the second worst in the world on IQAir, a technology partner of the United Nations Environmental Programme. IQAir's city pollution rankings compare 95 global cities worldwide with measured PM 2.5 data.
The PM 2.5 concentration in Chiang Mai is 23.9 times the WHO's annual air quality guideline value, said IQAir on its website.
PM 2.5 is one of the deadliest forms of air pollution tiny particles with a diameter of less than 2.5 micrometres or about 3 per cent of a human hair.
They can penetrate deep into the lungs, where they can either stay in the bloodstream for long periods or pass into the bloodstream unfiltered.
These particles can cause cancer, cardiovascular and respiratory diseases, and cardiovascular and respiratory diseases.
Residents in Chiang Mai and other northern Thai provinces have been reeling from poor air quality for more than a week.
There were 46 hotspots in the province on Wednesday, 35 of which were located in forest areas, according to the Environmental and Pollution Control Office 1 Chiang Mai. There were eighty-one other hotspots reported in Chiang Rai, Lamphun and Mae Hong Son.
On Tuesday, Chiang Mai governor Nirat Pongsitthavorn ordered various provincial work units to reduce the impact of air pollution on public health, including distributing face masks that filter out PM 2.5 and setting up roadside emission check-points to limit black exhaust fumes.