top of page

What kind of masks are useful in times of haze?

With the relaxation of precautionary measures in the wake of the COVID-19 outbreak, locals are no longer required to don face masks in the public. However, it seems that with the incoming haze, we might have to start wearing masks again. So the question is: how much do you know about masks?


There are 3 types of face masks commonly worn- cloth masks, surgical masks, and N95 masks.


Cloth masks filter droplets and can be reused after washing.

Surgical masks are single-use masks that protect wearers against sprays or splashes, and filter large particles in the air.

N95 masks have the highest protection as they filter both large and small particles, including PM2.5.


There is another type of mask called KN94 which filters 94% of the airborne particles, making it a good alternative during haze. There are also KN95 masks that have ear loops. But be cautious when purchasing them as there are counterfeits in the market.


Certainly, N95 and KF94/95 masks will be pricier than surgical masks.There is also bound to be discomfort with wearing these masks for prolonged periods. To circumvent these problems, MOH recommends that N95 masks can be reused up to 5 times unless they are soiled or dirty. We would advise getting a mask strap worn behind the head or applying moisturiser to reduce ear irritation.


There are 3 types of face masks commonly worn- cloth masks, surgical masks, and N95 masks.


Cloth masks filter droplets and can be reused after washing.

Surgical masks are single-use masks that protect wearers against sprays or splashes, and filter large particles in the air.

N95 masks have the highest protection as they filter both large and small particles, including PM2.5.


There is another type of mask called KN94 which filters 94% of the airborne particles, making it a good alternative during haze. There are also KN95 masks that have ear loops. But be cautious when purchasing them as there are counterfeits in the market.


Certainly, N95 and KF94/95 masks will be pricier than surgical masks.There is also bound to be discomfort with wearing these masks for prolonged periods. To circumvent these problems, MOH recommends that N95 masks can be reused up to 5 times unless they are soiled or dirty. We would advise getting a mask strap worn behind the head or applying moisturiser to reduce ear irritation.


PM2.5 is usually emitted from the combustion of fuels and wood, while PM10 is typically dust produced from construction sites, wildfires and industrial sources. PM10 is likely to be deposited on the upper surfaces of the lungs whereas PM2.5 could travel deeper into the lungs. Both PMs can be found in haze and are used in PSI tracking, but PM2.5 is the main pollutant of concern as they can infiltrate air-conditioned buildings through the air intake, openings and gaps, jeopardising the health of people staying indoors.


So what happens when we are exposed to PM10 or PM2.5? Short-term exposure to PM10 has been associated primarily with the worsening of respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), leading to hospitalisation and emergency department visits. Long-term (months to years) exposure to PM2.5 has been linked to premature death, particularly in people who have chronic heart or lung diseases, and reduced lung function growth in children. Collectively, PM2.5 and PM10 have been associated with premature mortality, irregular heartbeat, worsened asthma and aggravated respiratory symptoms such as coughing, wheezing and breathing difficulties. So now, how does one protect oneself against the health impacts of haze?


If the 24-hour PSI reaches unhealthy levels (101 and above), individuals with chronic lung or heart disease should avoid prolonged or strenuous exercises outdoors. Seniors, pregnant women and children should minimise outdoor exertion. If the one-hour PM2.5 concentration reaches elevated levels, healthy people should reduce strenuous outdoor activities, while vulnerable people should avoid such activities.


1 view0 comments
bottom of page