It is becoming increasingly known that airborne particles harm human health and that indoor air is often 1.5 times more polluted than outdoor air, but can be 4 times more polluted. So more people are asking how can I reduce air pollution in my home?
One of the things that most people do not yet realize is that is not just “pollution” which damages human health. It is becoming increasingly apparent that very low levels of airborne particles within the normal range damage human health. Three recent 3 scientific studies showed that mortality increases consistently with PM 2.5 (fine airborne particle) levels without any lower limit to this effect. So even at very very low levels, any increase in particle count increased mortality.
The United States Environmental Protection Agency (EPA) specifies a limit of 12.5 mcg/m³ as the upper limit of the safe level. As the 3 scientific studies mentioned above were published, this limit looked far too high. In September 2021 WHO published guidance saying that the safe upper limit for pollution levels should be considered to be 5 mcg/m³. So levels that had been less than half those considered safe in the United States are now considered unsafe. Even these levels may prove to be too high in time.
So really, we need to stop thinking of “pollution” as the problem, it is now clear that normal particle levels in the air are a health problem. This is borne out by County level data concerning particle pollution from the United States. There is data available for approximately 200 million Americans. For these Americans, in 98% were living in areas where PM 2.5 air pollution is above WHO safe standards. As air pollution in homes is 1.5 times that of air pollution outside the home, we can be fairly sure that to a good approximation 100% of Americans are breathing in the air that is deleterious to health at home.
So it really is an enormous problem, what can we do about it in our own homes? Fortunately a tremendous amount can be done.
On the whole, air purifiers can reduce airborne particle pollution by 80 to 90% if used properly. Ventilation also reduces the concentration of pollution. We should also lower our production of pollution in the home. Most important is to check with an air quality meter that we are being effective.
There are 22 ways to reduce air pollution in your home but first here is a list on illnesses you and your family can get form indoor air pollutants-
What Are the Health Effects of Indoor Air Pollution?-why should we bother reducing it?
Airborne particles have been shown in clinical or epidemiological studies, often multiple studies, to cause-
- Coronary heart disease-heart attacks
- Premature aging of the lungs
- Chronic obstructive pulmonary disease
- Skin problems including skin aging
- Kidney disease
- Cognitive decline-decrease in thinking ability
- Parkinson’s disease
- Vision impairment-age related macular degeneration and glaucoma
- Impairment of sense of smell
- Sleep disturbance
- Increased risk of psychiatric problems
- Decrease in fertility
- Increased miscarriage
- Exposure during pregnancy linked to neurological problems, asthma, lower IQ in child
- Children-lower intelligence and delayed psychomotor development, faster decline in cognitive function in adulthood
- Children-chest infection, asthma
- Children-increased obesity
- Children-increased psychiatric problems
- Children-death rate increased
- Premature aging?-ultrafine particles speed up several processes involve in aging
- Premature death
There are now studies showing that these affects occur even at airborne particle levels currently considered “normal”. So even if you do not live in a famously polluted area there is likely a greater than 90% chance that airborne particles are interfering with your health. Please see this article for further information.
So, if we choose not to do anything about the airborne particle count in our home, there are quite a few significant health problems that may run into. Children are not surprisingly especially vulnerable as their bodies are changing rapidly as they grow. The effects on the brain are worrying for both children and adults. Also increased incidence of heart attacks, dementia and premature death are a particular concern for older adults.
The possibility that an increased particle count leads to premature aging is a concern for everybody. However, although this is not proven, It has been shown in experimental situations that airborne particle counts can influence some of the mechanisms known to be associated with increased aging.
There are 2 main strategies for reducing airborne particle count/chemical pollutants –
- reduce the production of particles/chemical pollution
- remove the airborne particles/chemical pollution
1) Reduce the Production of Airborne Particles/Chemical Pollutants
1) Do Not Burn Wood or Other Fuels in the Home
A wood burner triples the fine particulate in the indoor air, opening the door of the wood burner to put more fuel into it causes this. It also pollutes the air of the surrounding neighbourhood.
Cooking is a Potent Source of Particle Pollution-by altering technique you can reduce pollution in your home
This is well illustrated by Professor Vance in the following YouTube video – 16 minutes 30 seconds and 25 minutes are particularly interesting-
2) Electric Induction Hobs Create Fewer Airborne Particles Than Gas Stoves/Ovens
Ideally switch from a gas hob to an induction hob. Burning gas in the home leads to an increase in both particulate and chemical pollution. As you will see, this makes only a small difference to the overall particle mass in the air. However it does make a very significant difference to the number of fine and ultrafine particles.
This is seen in the video (at 18.03 minutes) if you look at the smallest particles on the left of the graph there are many fewer particles for the electric hot plate than a propane gas burner. It is the fine particles that are mainly responsible for adverse health effects.
3) Boiling and Steaming Leads to Fewer Airborne Particles Than High Temperature Dry Cooking
So the less oven cooking or grilling that you do the better. Boiling or steam cooking will produce far fewer particles. This is because particles are particularly produced when organic matter such as meat or vegetables are heated to temperatures in ovens, frying pans or grills to well above 100°C (the boiling point of water). Also, any particles produced during boiling or steaming will tend to be trapped in the water and not enter the air.
4) Have an Extractor Hood Over the Stove With an Exhaust Fan That Ejects The Air to the Outside-particle pollution
5) Do Not Overheat Non-Stick Pans-chemical pollution
Once heated to above 300 degrees Fahrenheit non-stick pans may give off chemicals which can be toxic. In general you are better from a health point of view using stainless steel cooking equipment. There is the added health benefit of the difficulty cleaning a steel frying pan putting you off frying food and exposing yourself to advanced glycation end products which may cause premature aging.
6) Do Not Use Candles or Burn Incense Sticks-particle and chemical pollution
Candles and incense sticks produce high quantities of fine and ultrafine particulate pollution, some of which will enter your bloodstream. They will also cause a degree of chemical pollution. An alternative to using them in the home would be to use them on a veranda or balcony.
7) Do Not Smoke Cigarettes/Cigars or Vape in the Home-particle and chemical pollution
Burning any organic material such as tobacco creates particularly harmful ultrafine particles. The ultrafine particles in smoke tend to be at the smaller end of the size range and can easily enter our bloodstreams. From here they can irritate our arteries, causing heart attacks and even access our brains. So anything that causes smoke within the home, such as cigarettes or candles, is potentially damaging the health of the occupants.
This also applies to vaping, which increases PM2.5 concentrations and chemicals in the air.
Also the chemicals in cigarette smoke are famous for causing cancer, so this chemical pollution in the home is best avoided by not smoking inside or ideally at all.
8) Do not idle the Car in the Garage
Particles from internal combustion engines are particularly toxic. If you idle the car in the garage it is likely that some particles will enter your house. Even if they do not there will be a layer of them on everything in the garage and when you walk on them they will be agitated into the air and may enter your home.
9) Pets-particle pollution
Most pets produce animal dander from their skin. However saliva, urine and feces can also be allergenic. In general, pet owners are happy to accept the trade-off of increased particle pollution in return for the joy of having the pet. Of course with air purifiers and a robotic HEPA vacuum cleaner, the owner’s exposure to pet dander particles can be reduced tremendously. For further information please see this article “Best Air Purifier for Pets”.
10) Choose Different Home Office Equipment-particle pollution
Both laser printers and photocopiers can emit ultrafine particles which easily enter our bloodstreams. They have been linked to heart attacks and premature death. By buying inkjet printers, you can avoid this particle pollution.
11) Have Artificial Rather Than Real Flowers-Particle Pollution
Real flowers will inevitably release pollen into the home, which can then be breathed in by the occupants. An alternative would be to have artificial flowers.
12) Prevent Your HVAC System From Becoming a Source of Particle Pollution-regular maintenance
13) Personal Care Products-soaps, shampoos etc-chemical pollution-buy nonscented products
An average personal hygiene product will contain 15 to 20 different volatile organic compounds. These are particularly prevalent in scented products. So using unscented products is best.
Semi volatile organic compounds are found in nail polish, soaps, shampoos and hair sprays. So using them in moderation is best.
14) Chemicals From New Carpets and New Furniture-allow to “off-gas”
Due to chemicals used in the manufacture of carpets and furniture they are a considerable source of chemical pollution in the home. Pressed wood furniture releases formaldehyde into the air.
If possible, leave your carpets and furniture outside for 3 or 4 weeks in a garage or warehouse. If this is not possible, you could put them into a room with the windows open and avoid going into the room for the first 3 weeks. This will let volatile organic compounds evaporate from the carpets or furniture. It will not completely get rid of the volatile organic compounds but more evaporate off at the start, and so you will avoid the worst period of chemical pollution from them.
The EPA recommends a minimum of 3 days of heavy ventilation, that is with windows open and a fan on. This is an absolute minimum.
An air purifier with a good activated carbon filter to adsorb the chemicals will be very helpful, for the best air purifiers for this please see this article-“Best air purifiers for smoke“.
15) Chemicals From Dry Cleaning-allow to “off-gas”
Let dry cleaning chemicals evaporate off either by leaving the clothes at the dry cleaners for a day or two before collecting. Or bring the clothes home and air them outside or in the garage.
16) Chemicals From Building and Decorating Materials-chose carefully what you buy and use ventilation
Paints and varnishes can release high concentrations of volatile organic compounds (VOCs) into the air. It is now possible to use paints and varnishes with a low VOC content so you are best buying these. Lead paint is still present in an occasional old building, it should be treated with care to avoid high levels of lead in your body.
Semi-volatile organic compounds also enter the indoor air. The main way of limiting these is to buy wisely. Plasticisers (phthalates) are found in for instance vinyl flooring, and adhesives. Furnishings and some building materials are often treated with flame retardant chemicals. Also if you buy an older home many of the semivolatile organic compounds will have evaporated into the atmosphere long ago so that you are breathing in less than when the house was new.
17) Do Not Spray Chemicals Into Your Indoor Air-air “fresheners”, cleaning products, and insect repellants.
Ideally you would avoid using air “freshners” which is really introducing more chemicals to mask the smell of the volatile organic chemicals in your home causing odors. It is much better to throw the source of the odor out if possible. If this is not possible then an air purifier with a good carbon filter will make a tremendous difference and may virtually get rid of any odor.
Rather than use cleaning chemicals, use more natural cleaning products made of things such as lemon juice, apple cider vinegar, and baking powder.
Napthalene is used in insect repellents and can be at very high concentration in homes where insect repellent is used. This can irritate the eyes and respiratory system as well as there being some concerns regarding its long term toxicity, even being associated with cancer.
18) Excess Moisture Will Let House Dust Mite and Mold Grow-check humidity periodically and if high use a dehumidifier
Although moisture is not a pollutant in itself if excessive it will allow the growth of house dust mite and mold. If the relative humidity is kept below 55% then house just might will not grow and if it is kept below 80% neither will mold. So especially in winter it would be good to check some humidity readings.
19) Mend Leaks if Present Especially if Leading to High Humidity in the Home
20) Outdoor Pollutants Entering the Home-make sure doors and windows fit and gaps around service pipes entering your home are sealed
Outdoor pollutants can be particle pollution e.g. car combustion fumes, chemicals e.g. pesticides or even radioactive e.g. radon. The best way of preventing these entering your house is to make sure all the doors and windows fit well, and close the gaps in the building envelope whether service pipes come in. Cracks in the ceiling and floors may need sealing. Even so particles of 0.3 micrometre are extremely efficient at penetrating into buildings but you may be able to reduce the indoor pollution to half of that outside.
However, sealing your house well is a double-edged sword it also does not let pollution you have created within the house out. So the more you seal your house the more you will have to have a schedule for opening the windows and ventilating the house periodically.
21) Construction Materials May Cause Pollution in the home
Depending on the construction of your house there may be particular pollution from construction materials. Asbestos is the most famous example of this, causing asbestosis and mesothelioma. If you think you could have asbestos in your house you should not disturb it and seek specialist advice concerning its removal.
Many other construction materials release volatile organic compounds into the indoor air. You can buy air quality meters to check for these and if you find them you will need specialist advice and air purifiers with good carbon filters, the best ones can be found here -“Best air purifiers for smoke“.
22) Radon From Rock Under the Home-if levels significant specialist barrier and under home ventilation installation needed
Unfortunately, air purifiers cannot remove radon, it does not stick to the chemical filter. Radon seeps into buildings from the earth below the building. High levels have been implicated in cancers particularly lung cancer. So ideally you would check your radon level. Then to lessen exposure you need to have professional help to build an efficient barrier between the ground and the house as well as installing a ventilation system in the basement areas. The ventilation system is to remove the radon to the outside before it can enter your home.
23) Carbon Monoxide-alarms needed near devices burning gas
We cannot smell or otherwise detect carbon monoxide and yet it binds to hemoglobin to interfere with oxygen transport in our bodies. Carbon monoxide poisoning can be fatal. It is usually produced by gas burning appliances which are not working well or have been set up incorrectly. Again an air purifier will not remove carbon monoxide and so the best strategy is to have a carbon monoxide alarm in any room where gas burns. This will then alert you to the rising carbon monoxide level, giving you a chance to escape from the area before you come to harm. You or someone else can then turn the appliance off, open the windows to let fresh air in and the carbon monoxide out.
2)Remove Airborne Particles/Chemical Pollutants
So having looked at ways to decrease the entrance of pollution into your home and the production of pollution in your home let us now turn to how to purify the air and so reduce air pollution that way.
24) Ventilate Your Home Periodically
Ventilation is a crucial part of reducing home pollution, this is because a few pollutants cannot be removed even by air purifiers. Only ventilation will remove them from the home to the outdoor air. Ventilation is especially useful during and after cooking and cleaning.
In trying to increase the energy efficiency of our homes, they are becoming more sealed with less ventilation. There are mechanical ventilation systems and building regulations regarding ventilation. However in a study only 3 out of 80 homes in the UK met ventilation guidelines.
25) Use Extractor Fans +/- an Air Purifier in the Kitchen When Cooking
The kitchen is probably the major source of pollution in most houses due to cooking. In addition cooking causes both particle pollution and chemical pollution. So it is one room that would particularly benefit from an air purifier. It is also sensible to have a powerful extractor fan they can be switched on when cooking is underway.
26) Cook on the Back Burners of the Stove to Reduce Air Pollution
If you have an extractor hood over the hob, then cooking where possible over the 2 back burners water induction coils makes extraction of the fumes from cooking much more efficient. The fumes from the front to burners reduction coils can escape into the room far too easily before they get sucked into the extractor hood.
27) Vacuuming-a robotic vacuum with a HEPA filter is best
Obviously an air purifier cannot remove particles that fall to the floor before the air gets to the purifier. These particles on the floor need to be vacuumed up. Otherwise when people walk across the floor they will simply be ejected into your indoor air again. The vacuum cleaner needs to have a true HEPA filter otherwise there is the risk that it will pick up the particle and they will simply be ejected from the vacuum cleaner through the weaker filter back onto the floor.
From personal experience this is best done with a robotic vacuum cleaner as cleaning cycles can be much more frequent.
When the vacuum is emptied the particles are removed from the house forever.
28) Use Air Purifiers to Reduce Particle Count/Chemicals
The use of air purifiers is the most effective way of improving indoor air quality.
Air Purifiers Can Be 80-90% Effective at Reducing Airborne Particle Count if Use Properly
The only way to reduce the particle count in your home very significantly is to use an air purifier. Here is an example of one of my air purifiers reducing the particle count of 0.5 µm diameter particles–
The above experiment used a Trotec PC 200 particle counter.
HEPA filtration can easily remove these particles from the air-
- House dust mite
- Pet dander
- Mold Spores
- Dust-household and atmospheric
- Brake dust
- Tire dust
- Vehicle exhaust particles
- Smoke particles both cigarette and wildfire
Air Purifiers Can Also Remove Chemicals From the Air
Almost all air purifiers have an activated carbon filter which adsorbs most chemicals. The fibrous filter which traps particles has pores in it that are too large to trap molecules of gaseous chemicals. So the chemicals pass straight through the filter. Fortunately when these chemicals come into contact with activated carbon they stick to the carbon as there is a weak intermolecular bond formed between the carbon and the chemical. This is an extremely effective way of removing chemicals from the air and a small amount of carbon can reduce the large amount of gaseous chemical.
How to Choose and Use an Air Purifier
In one review of studies where air purifiers were used, fine particulate matter was reduced between 23-92%. Bear in mind the EPA recommends a minimum reduction of 80%. So even in experimental studies with training in how to use the air purifiers, most air purifier users failed to hit this target. On the other hand, it shows that air purifiers, when used well, can decrease particle count by 90%. This just emphasizes the importance of how you use the air purifier.
- Buying an air purifier-the air purifier should have a true HEPA filter, adequate air flow (CADR) at a noise that you can tolerate for long periods. The air purifier should be “smart” that is programmable or capable of being made smart. The most difficult part is buying one with an adequate air flow at a noise that you can tolerate for long periods as most air purifiers are too loud on their maximum fan speed and manufacturers usually do not give data on air flow and noise at lower fan speeds. There is helpful advice about buying an air purifier here-“Buying an air purifier”. Alternatively, just buy the recommendations on this site. If you want the quietest air purifier you may wish to read this article-“Best Quiet Air Purifiers“, if you need one that will remove particles very well but is particularly good at removing chemicals from the air, for example from forest fires, please see this article-“Best Air Purifier for Smoke“.
- Position the air purifier at least 12 inches from any wall-so that the air coming out of the air purifier joins in with the circulation of air in the room. There is advice about using an air purifier in this article-“How to Use an Air Purifier“.
- Run the air purifier for at least 30 minutes before entering the room. This is because it takes an air purifier this long to reduce the particle count in the room. So the air purifier that you buy needs to be smart or capable of being made smart by plugging it into a smart plug.
- Run the air purifier continuously when you are in the room at the highest setting that you can tolerate long term. This is because the higher the setting that you run the air purifier on the lower the particle count in the air will be. There is no lower threshold known below which human health does not improve, so the lower the particle count/PM2.5 the better. Health aspects of particle count/PM2.5 are outlined in this article-“Airborne Particles and Chemicals Affect Us All Now“.
- Never run the air purifier using its inbuilt sensor-there are 7 reasons that you should not do this as outlined in this article-“How to Use an Air Purifier“.
- Always test the air with an air quality meter where you are going to sit at the height in the room where your mouth and nose are. Comparing the measurements before and 45 minutes after switching the air purifier on there should be at least an 80% reduction in particle count as the EPA recommends. Testing that the particle count/PM2.5 is adequately reduced by your air purifier is the most important thing that you need to do. Air quality meters can be brought really quite cheaply eg $35, there is a helpful article about them here-“How to Test Air Quality in Your Home“.
- How many air purifiers do I need?-at least 2 but maybe 5 or more. Please see this article “How many air purifiers“.
29) Convert Your HVAC System Into a Whole Home Air Purifier
Most HVAC systems would be more efficient at removing particles with a filter change. HVAC filters are graded on the MERV (minimum efficiency reporting value) scale. As can be seen from the diagram below a Merv 6 filter will only remove about 10% particles 0.2 um in diameter whereas a MERV 16 filter will remove about 95% of these particles. So a change in the MERV specification of your HVAC filter can make a very big difference. The problem is as the efficiency of the filter, MERV rating, increases so does the resistance to airflow.
An increase in resistance to airflow can damage the HVAC system. Almost all HVAC systems will not be able to take a HEPA filter, but many will be able to take a MERV13 filter. With some remodeling it may be possible for your HVAC system to take a MERV 16 filter. For further details please see this article – “The best HVAC filter“.
To use your HVAC system as a whole home air purifier you will need to run the HVAC fan all the time you are in the home. Fortunately this is possible for most HVAC systems.
As an increase in filter specification can cause damage to your HVAC system, you should consult an HVAC engineer before upgrading to check that your system will be able to cope with the filter you want to use.
For further information on converting your HVAC system into whole home air purifier please see this article –”Make a dream “whole home air purifier” from your HVAC system.
Also change your HVAC filter regularly according to the manufacturer’s specifications.
On the whole, to purify the air, an air purifier is by far the most effective method. However, there are some things that cannot be removed even by an air purifier e.g. radon and so periodic ventilation is essential.
Protect Your Children With an Air Purifier When Doing Activities Likely to Expose Them to Chemicals
When children do arts and craft activities with glues or paints, depending on the type of glue or paint, you may wish to consider having an air purifier with the carbon filter to remove chemicals from the air.
30)Protect Yourself With an Elastomeric Mask With Particle/Chemical Filters When Doing DIY
Whenever you are doing DIY or cleaning with chemicals, your first thought should be “does this job need me to wear a mask to stop my breathing in either particles or chemicals?”. An elastomeric mask with particle or combined particle and chemical filters will give you tremendous protection–please see this article “what is the best air purifier mask?“.
Especially Vulnerable People
Children and Pregnant Women
Children are especially vulnerable to both particulate and chemical air pollution. Their central nervous systems are developing and can be quite adversely affected by pollution- please see this article “The 13 health problems from air pollution“. This also applies to the unborn child, so pregnant women may wish to consider having an air purifier.
Deterioration in arteries is almost universal as we age. So that by the age of 75 years old almost all people have some evidence of arterial degeneration. Air pollution particularly ultrafine particles enter the bloodstream and make the areas of degeneration in the arteries unstable. This degeneration can then crack, causing a clot to form in the the artery leading to a heart attack. One way to counter this would be to breathe purified air from an air purifier.
There is a study from the Cleveland clinic showing that arterial degeneration was present in a 85% of people older than 50 years. So you may wish to start purifying your air at a younger age.
Always Check With an Air Quality Meter
Whatever you do to improve the air quality, always measure the change. This is because our senses are not good at detecting the level of airborne particles, radon, carbon monoxide or chemicals. The measures that we take may seem to be obviously effective, but for some reason there may be a problem. Unless we measure the effect of the air purifier or other intervention, we will not know for sure that it is effective and could be breathing in polluted air for years.
This applies particularly to airborne particles and radon. Checking chemicals in the air is more difficult. There are meters that will measure volatile organic compound and formaldehyde in the air but other chemicals can go undetected. Also air purifiers are good at removing most but not all chemicals.
When using an air purifier, always test the air where you are going to sit at the height in the room where your mouth and nose are. Compare the measurements before and 45 minutes after switching the air purifier, on there should be at least an 80% reduction in particle count as the EPA recommends. Testing that the particle count/PM2.5 is adequately reduced by your air purifier is the most important thing that you need to do. Air quality meters can be brought really quite cheaply eg $25, there is a helpful article about them here-“How to Test Air Quality in Your Home“.
So there are at least 26 ways by which you can lower air pollution at home. The most effective of these is to use an air purifier. There are now air purifiers that lower particle count by 80 to 90% provided –
- The air purifier that is brought is able to supply enough air flow at a noise tolerate to deal with the room.
- That you run it constantly at an air flow that will adequately process the air in the room.
- It has a true HEPA and activated carbon filter.
- You test the particle count reduction that it produces–this is most important of all.
If you manage to reduce the airborne particle count in your home it is likely that your health outcomes will be significantly better long-term.
Best Air Purifier For a Kitchen
Best Air Purifier For a Small Room