THE haze seems to have returned and people are getting worried about the impact it might have on their health as well as that of their families. Some have turned to using air purifiers to help improve the air quality in their homes.
Is it true that an air purifier will help beat the haze?
Verdict:
TRUE (with caveats)
A quality air purifier from a reputable company will definitely improve the air quality within the house.
That said, it really depends on what kind of air purifier you are using as well as the method it uses to clean the air.
Before getting into the nuts and bolts of what's best, one first has to understand what exactly it is trying to filter out. In essence, what is the "haze"?
Common indoor air pollutants include such things as dust, pet hair, dander, pollen (if you keep a lot of flowering plants in the house) and volatile organic compounds responsible for the various – for lack of a better word – "aromas" in a house. This could be from cooking, perfume, cleaning products or even people and pets.
The haze, however, is the result of the mass open burning of farmland and plantations, so it mostly consists of smoke and dust which can be categorised as coarse or fine particulate matter.
"Coarse" inhalable particles that have a diameter of 10 micrometers (μm) or less but more than 2.5μm, are referred to as PM10. Particles that are less than 2.5μm in diameter are known as "fine" particles or PM2.5.
Both are bad for you as they can irritate your eyes, nose, and throat, and are even more problematic if you have other health complications such as asthma.
However, PM2.5 is far more dangerous as they can get into the deeper part of your lungs and even into your blood.
So during this time of haze, an effective air purifier would have to be able to deal with not only common household air pollutants, but the particulate matter (both PM10 and PM2.5) from haze.
For that, you would need an air purifier that uses Hepa (high-efficiency particulate air) filters.
In order for a filter to get ISO certification as a Hepa filter, it would need to filter out 99.95% of particles of 0.3μm diameter. This means the air filter must be able to clean out particles as small as a virus (0.02-0.3 μm), never mind PM2.5.
There are many air purifiers on the market that use Hepa filters, so you would just need to choose one from a reputable manufacturer that is able to clean the air for the room it is in. Basically, a bigger room needs a larger unit to effectively filter the air in a reasonable amount of time.
If you don't have that many rooms in your house, you might only need to have one device that you move from room to room.
Saying that, it is best to close all doors and windows when the purifier is running as this ensures the air can be properly "cleaned". Also, it would be rather pointless to leave a window open to "air your room" if the outside air quality is bad.
Also, if your home is air-conditioned, check to see if it uses Hepa filters as some consumer units boast the feature.
Another popular "air purifier" here are air ionisers.
An air ioniser releases negative ions into the air that attach themselves to tiny particles such smoke or dust, causing them to clump together so that they fall out of the air and stick to surfaces thus "cleaning" the air of those particles.
These devices work very well with small particles but do not do so well with larger particles such as pollen or larger dust particles.
While these devices are cheaper than air purifiers, they do not actually remove the particles from the air – they only force them out of it.
You would have to make sure to vacuum up as much of it up else once the negative charge wears off, or it will be released once again into the air once disturbed.
Furthermore, most air ionisers have a nasty habit of belching out ozone gas as a by-product of the ionisation process. While the gas is great high up in the stratosphere, down here it is a lung irritant that has been shown to affect the respiratory, cardiovascular and central nervous systems. Acute exposure to ozone can even lead to death.
So in conclusion, get a good air purifier that uses Hepa filters are great if you are concerned about the haze but steer clear from air ionisers. They don't work as well and may actually worsen the air quality in your home. Alternatively, if your home is air-conditioned, check to see if it uses Hepa filters. If they do, then you don't have anything to worry about.
References:
1. https://www.who.int/news-room/fact-sheets/detail/household-air-pollution-and-health
2. https://ww2.arb.ca.gov/resources/inhalable-particulate-matter-and-health
3. https://www.cdc.gov/air/particulate_matter.html
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6650878
