Do face masks really help with haze?

Our memories are short-lived, so there may be a need for a reminder on this as we struggle to deal with the current extremely poor air quality – a problem that has plagued us for two decades.

The announcement that our National Disaster Management Agency has sent 500,000 face masks to Sarawak amid the worsening trans-boundary smog from Indonesia is not reassuring. From all available information, the masks sent are three-ply surgical masks and of little value. It is important that misinformation and misleading actions not be created by government sources as these may confuse the average person on the street.

I have discussed, in FAQ style, the key issues regarding the value of face masks in this recurrent crisis.

Are normal surgical masks useful? This refers to single-ply (usually white) or three-ply masks (usually green or blue and thicker). How long do surgical (three-ply) masks last?

It is important to recognise that most of the harmful substances in the smoke/smog coming our way consist of toxic gases and very small particles, most under 2.5 microns in size.

Analysis of the air coming from the Indonesian haze suggests that the chemicals we are inhaling include ozone, carbon monoxide, cyanide, ammonia, formaldehyde, acrolein and benzene, some with long-term carcinogenic effects.

In addition, the ultra-fine particulate matter (PM 2.5 microns or less) often lodge deep in the lungs and have short and long-term effects on cardiovascular and pulmonary diseases.

The single-ply surgical masks (usually white) are ineffective. The usual three-ply surgical masks (usually green or blue and thicker) also cannot filter toxic gases and fine particles (< PM 2.5 microns). They may offer some protection against larger particles that irritate, and hence may be useful for some outdoor activities such as biking.

But even the health ministry website advisory on “Usage of Personal Protection During Haze” says “Airborne particles causing haze may be as small as 2.5 microns. The use of the surgical mask will not prevent one from inhaling the small airborne particles.” (See: http://www.moh.gov.my/index.php/pages/view/190).

Once these surgical masks are damp or you cough or sneeze in them, they are ineffective. They last at best 30-60 minutes, so they need to be changed very often.

You may argue that sending 500,000 three-ply surgical masks to Sarawak is better than doing nothing. But if they last one hour and are largely ineffective, who are we fooling? Why go to this expense when the resources could be put to better use to fight the real problem and, more importantly, not mislead the public?

What about home-made or purchased cloth masks?

Many have resorted to the use of cloth masks as they are cheaper and can be washed and re-used. But a number of studies have shown that they are largely ineffective for PM 2.5 microns (and below) as well as toxic elements in the smoke. They also retain moisture easily and increase your risk of getting an infection. Wearing a face mask may give you a false sense of security – you think you are protected when in fact you are not.

Do N95 masks protect against the haze?

N95 masks are called this because they filter at least 95% of airborne particles. They are more effective but only if worn correctly with a good fit to the face of the wearer. They also work only if air comes in via the filter. Leaving gaps means the mask fails to offer protection.

N95 masks are not easy to wear for long. They increase the effort it takes to breathe, reduce the volume of air and can cause discomfort. Care is required in their use by the elderly, children or those with cardiac or lung conditions. There was a recent suggestion to keep a small window in the mask to help children breathe easier, but this defeats the mask’s function. N95 masks are not that cheap and do have to be changed periodically.

Is staying in-doors useful? Will closing all our windows/doors and using air conditioners and air purifiers work?

The general opinion is divided on this. Generally, the air we breathe outside and inside the house is the same. The reason for staying indoors is to decrease outdoor activities and our exertion. Exerting ourselves means breathing in more of the toxins faster and increasing tissue damage.

If we close all entry points, some studies have shown a build-up of harmful toxins indoors. Air conditioners cannot filter out fine particles and gases and also damage the environment further (two degree centigrade rise in city temperatures with rampant air conditioner use). Those selling air purifiers make lots of claims that still require detailed studies regarding their efficacy.

Will our long-term health be affected by the smoke/smog? How about our own ambient pollution levels?

Authorities want to reassure us that breathing in smog/smoke for a few months every year for decades is harmless. No one believes this. There is some immediate effect in terms of respiratory irritation but breathing in the chemicals mentioned above will in the long term result in a significant impact on lung and heart health and cancer risks with an increase in premature deaths (shortened life spans).

We must see this seasonal haze/smog problem in the context that more than 90% of our population is consistently exposed to PM 2.5 levels above WHO recommendations (see World Bank Data: https://data.worldbank.org/indicator/EN.ATM.PM25.MC.ZS). Our daily background exposures are already exceeding safe standards and these yearly spikes for one to two months exacerbate our worsening air pollution and health.

We require honest, meaningful responses from our government and a decisive plan to end the current crisis and prevent the yearly occurrences. Already we are paying the unrecognised price of two decades of seasonal pollution from our neighbour (possibly thousands of people with shortened life spans each year). We cannot continue with this in the face of our worsening local ambient air pollution.

Dr Amar-Singh HSS is a senior consultant paediatrician.

The views expressed are those of the author and do not necessarily reflect those of FMT.