The Air Purifier Debate
Before looking at the scientific evidence relating to whether or not air purifiers really work, it’s worth mentioning that there are in fact different types of air purifiers. Each type operates in a different way and uses different scientific processes to achieve the goal of purifying the air that circulates within your home environment.
For the purposes this post, I am simply concerned with the question of whether there is evidence to show that good quality air purifiers in work as intended. I am not going to specifically assess the merits of the different types of air purifiers that are available to buy.
The question that I am interested in is simply this … do air purifiers do what they are supposed to do, or are they just an expensive waste of money?
As a father of 4 young children, and as a cat owner with mild cat allergies, I have a personal interest in finding out whether or not air purifiers really work.
I am not a scientist, but I have previous experience of reading, understanding, and summarising scientific research papers.
I have looked in detail at what I believe to be the most important scientific studies in relation to the efficacy of air purifiers. I want to share my conclusions on the issue of whether or not those studies show conclusively that air purifiers really work, and I hope to do so in a manner that non-scientists can understand.
You can’t make an informed decision about whether or not it is worth investing money in an air purifier for your home unless you can first understand what they are designed to do and what that have been shown to be capable of actually doing.
Now, I won’t be reciting huge chunks of the research papers or referring to complicated scientific concepts, but I have provided links to the most important research papers in this area towards the bottom of this page so that you can read them for yourself if you wish to do so.
So, what exactly is the purpose an air purifier?
The Purpose of Home Air Purifiers
Home air purifiers are designed to remove unwanted and potentially harmful particles from your home environment.
The types of particles that the manufacturers of air purifiers commonly refer to within their sales pitches include dust, pet dander, pet odors, cigarette smoke, other smoke, mold spores, bacteria, and viruses.
In addition, you may have heard people talking about PM2.5 and wondered what on earth they were talking about.
In short, PM2.5 is the technical term to describe “fine particulate matter”. PM2.5 is matter that is so small that it is able to travel deeply into the respiratory tract of humans. This can cause serious short-term and long-term health problems, especially to the young and old.
Outdoors, common sources of PM2.5 include motor vehicles, industrial manufacturing plants and any operation that involves burning fossil fuels. Indoors, common sources include tobacco smoke, cooking gases, fireplaces and kerosene heaters.
You can read more about PM2.5 here, but the simple fact is that they are potentially very harmful to humans and it is hardly surprising that people are keen to reduced their exposure to these particles as much as possible.
What you have to understand, however, is that there are 2 separate hurdles that those promoting air purifiers have to overcome if they are to prove that air purifiers work in the full sense of the word; namely:
- that they remove significant amounts of the targeted particles; and
- that removing those particles actually improves human health or relieves symptoms.
#1 Do Air Purifiers Remove significant quantities of targeted particles?
This is by far the easiest question to answer because it is quite easy to test.
Air purifiers have been tested many times and there is little doubt that the best quality ones do indeed remove significant quantities of the targeted particles from your home environment.
Some air purifiers work much better than others but, in general terms, it is widely accepted that the evidence shows that air purifiers are capable of removing the targeted particles from your home.
In fact, air purifiers are officially rated according to the extent of their particle removal abilities.
The smaller portable air purifiers are given a Clean Air Delivery Rating (CADR).
The larger “whole building” air purifiers are given a Minimum Efficiency Reporting Value (MERV).
I’m not going to explain the complexities of these rating systems within this post, but they exits because it there is no doubt that air purifiers do infant purify the air.
So, high quality air purifiers are effective in removing significant quantities of air particles but that fact, of itself, does not prove that an air purifier will actually protect the health and comfort of you and your family.
#2 Does removal of those particles improve health?
Those who buy air purifiers do so for a variety of different reasons.
Some have allergies and hope that an air purifier will remove enough of the offending allergens from the home environment that the their symptoms will cease, or at least lessen in severity.
Others want to remove certain air particles in order to improve their asthma or simply because they want to protect themselves against the longer term effects of excessive PM2.5 contaminants.
Accepting, as we must, that air purifiers are capable of removing these particles from the home environment, does the available scientific research prove that this particle removal can achieve the health outcomes that people are looking for?
The Scientific Studies
There have been a number of studies into the effects of removing particles from the home upon the those suffering from asthma and allergies.
Those studies have proved inconclusive when viewed as a whole.
Some studies have shown significant benefits whilst others have shown no benefits at all.
You can read about those studies here:
- Reduced symptoms in those with asthma and/or allergies
- HEPA air cleaners led to significant reductions in unscheduled hospital visits by asthma sufferers, but not subjective symptoms
- HEPA air cleaners led to no improved lung function amongst asthmatics and pet allergy sufferers
- HEPA air filers can reduce allergic respiratory symptoms amongst rhinitis and asthma sufferers
- Air filters may offer substantial reductions in particulate matter, leading to improved lung function
- Air filtration associated with improved endothelial function and decreased concentrations of inflammatory biomarkers but not markers of oxidative stress
Should I Buy an Air Purifier?
I would not even consider any air purifier that emitted ozone into my home since there is pretty clear evidence that ozone is hazardous to human health and so this would probably outweigh any positive effects of air filtration.
But, what about the others?
Although the scientific evidence does not conclusively show that air purifiers work, I can quite readily understand why people remain willing to spend significant sums of money on these machines.
Aside from the ozone-emitting ones, no-one really suggests that air purifiers themselves can cause harm to humans. So, if the scientific evidence suggests that they have been found to work in certain situations, and if you or one of your family members suffers from one of the medical conditions that studies have shown might alleviate by an air purifier, buying one becomes a perfectly logical decision.
Having made the decision to buy an air purifier, the next big challenge is to decide which of the many different model to choose.
Get in Touch
If you have any views or personal experiences to share in relation to the question of whether or not air purifiers really work, I would love to hear from you. Just leave a comment in the box below. I would also love to know which air purifiers you have used and what, if any, benefits you gained.