Bangkok smog: Stuff common face masks with tissue to filter tiny dust particles PM2.5, Thai research finds

A woman wears a mask as she commutes to work, in Bangkok, Thailand on Jan 16, 2019.
A woman wears a mask as she commutes to work, in Bangkok, Thailand on Jan 16, 2019.PHOTO: REUTERS

BANGKOK (THE NATION/ASIA NEWS NETWORK) - As high-quality face masks to protect users against dangerous smog are in short supply, research found that common face masks with several levels of additional tissue paper or a folded handkerchief inside may suffice to protect Bangkok residents from small airborne dust particles.

The research, which is being widely circulated on social media, was conducted by Chiang Mai University biochemistry and clinical chemistry researchers Usanee Vinijketkamnuan and Khanittha Punturee in 2008.

It found that a normal face mask plus tissue paper or handkerchief stuffed inside could screen as much as 75 to 90 per cent of dangerous airborne dust particles smaller than 2.5 microns in diameter, known as PM2.5.

The high-quality face masks recommended by the authorities can screen as much as 87 to 96 per cent of PM2.5, the research found. These include masks of 3M 8210, N95, and 3M 9002A standards.

Without the additional stuffed tissues or napkin inside, however, a normal face mask can screen only 48 per cent of small particulates.

Home-made masks made from cloth or a handkerchief, however, cannot offer wearers any protection from small particles.

Public should not panic

The research also found that a high concentration of dust particles badly affects lung cells, alveolar cells and white blood cells, causing them to die.


Without any mask, the particles can kill as much as 40 per cent of alveolar cells, while high-quality masks including 3M 8210, N95, and 3M 9002A can reduce that number to 20 per cent.

However, a normal face mask, with or without stuffed tissue paper, cannot protect alveolar cells from the dust particles, the research shows.

Meanwhile, the government has warned the public not to panic.

PM2.5 are 25 times smaller than a hair's width and can enter the lungs, causing respiratory problems.

Still, the public should not panic, said Department of Health Deputy Director-General Amporn Benjaponpitak.

People can protect themselves by wearing two layers of normal face masks, she said, if they cannot find any N95 face masks for sale in stores.

Dr Amporn also recommended that city dwellers avoid outdoor activities and stay indoors, especially in the morning when the amount of airborne dust is most severe.

She also warned against wearing a common face mask and an N95 mask at the same time, as the combination may obstruct breathing.