‘Authorities have misled people’ about health peril of air pollution

The Nation 22 March 2018 | PATINYA SRISUPAMART

A MEDICAL specialist has brought home the human cost of the air-pollution problem plaguing Thailand, stating yesterday that the mortality rate increased by 0.3 per cent for every 10 micrograms of small dust particles measuring 10 microns (PM10) in the air.

Professor Dr Chaicharn Pothirat, who leads a unit dealing with respiratory disorders and allergies at the Chiang Mai University’s Faculty of Medicine, highlighted the alarming statistic yesterday to bring attention to the ongoing air pollution.

The information, he said, came from research conducted in Europe and the United States.

“Developed nations will issue warnings and may even order evacuations if the PM10 amount ranges between 80 and 110 micrograms,” Chaicharn said.

Yesterday, the PM10 level in Chiang Mai’s Muang district stood at about 114.75mg.

In Thailand, the Pollution Control Department (PCD) still insists that up to 120mg of PM10 is safe.

The PCD’s air-quality criteria also use particulate matters measuring 2.5 microns (PM2.5). If the PM2.5 amount is above 50mg per cubic metre of air, it is said to be beyond safe limits. The latest checks show that the amount of PM2.5 in Chiang Mai’s Muang district is 103.3mg per cubic metre.

According to Chaicharn, developed nations have embraced guidelines of the World Health Organisation (WHO) that suggest PM10 should not exceed 50mg and PM2.5 should not exceed 20mg each day.

“The current guidelines by Thai authorities have misled people into believing that air in their area is still good enough to live a normal life,” Chaicharn said. “In fact, when the PM10 amount exceeds the 50mg benchmark, there is a health risk to respiratory systems, hearts and brain blood vessels.”

He added that staying indoors when air pollution is serious might not be safe either.

A test at the Chiang Mai University found that the air quality inside a building, even in air-conditioned rooms, was hardly different from outside if people kept coming in and going out of the building. “When people frequently open and close doors, dust will also come in,” Chaicharn said.

A Facebook user, whose account name is Kittipong Tongkatsu Teekaput, also warned people to think twice about wearing N95 respirator masks for outdoor exercise. These safety devices cover the nose and mouth, and help protect the wearer from breathing in hazardous substances such as small dust and mould.

However, the Facebook user tested the N95 while cycling in Chiang Mai and he found that his heart rate was much higher during the exercise and his cycling speed had significantly dropped.