We are concerned about air pollution with all the trucks, cars, airplanes, and industrial plants pouring pollutants into the atmosphere.

Rightfully so.

But what about indoor pollution?

Although outdoor air pollution is a serious issue, you would be surprised to learn that indoor air pollution causes a lot more problems that outdoor pollution.

The quality of the air in your own home can be worse than the air outside. Surprising but true.

The basic principle of a healthy home is having a clean, dry, well ventilated place, free from pollutants and pests, where the risk of poisoning and respiratory illnesses is minimized.

Levels of Pollution in Homes

Experts like to cite the results of various studies that have determined the levels of some organic compounds being 2 to 5 times higher on average indoors than outdoors.

What is even more troubling is the fact that certain household activities, like pain stripping, can increase these levels more than thousand times than the outdoor levels.

Indoor Air Pollution Causes

What causes indoor air pollution?

There are countless things that can have a negative effect on the quality of the air in your home.

A lot of people have serious reactions to common allergens such as pollen, pet dander, dust, and/or mold.

Another serious source of indoor air pollution is known as VOCs or volatile organic compounds. There are literally several thousands potential sources of VOCs.

Paint as VOC source
Paint is one of the common VOC source

The concentration of VOCs indoors can be up to 10 times the outdoor concentration.

Volatile organic compounds are gases that are emitted from common household items from building materials such as paints, paint strippers and other solvents. We can also count in various adhesives, household cleaners, nail polish removers and cleaning supplies, aerosol prays, building materials, furnishings, glues, adhesives, disinfectants, wood preservatives, air fresheners, moth repellents, automotive products, stored fuels,… the list goes on.

Symptoms of Exposure to Indoor Air Pollution

Various organic compounds can cause various health effects. The severity of the symptoms varies greatly from extremely severe in case of very toxic chemicals to no known effects in other less dangerous compounds.

When it comes to allergens the most common symptoms are things like watery and itchy eyes, congestion, sneezing, itching and respiratory problems.

Exposure to volatile organic compounds can lead to acute short term and chronic long term problems.

VOCs can cause headaches, skin rashes, difficulty breathing, loss of coordination, fatigue, nausea, dizziness, difficulty breathing, or vomiting. Visual disorders are also possible as immediate symptoms. Other symptoms include memory problems, liver and kidney damage, increased risks of cancer, and central nervous system damage.

There can be many more symptoms.

Of course, as with any other pollutant, the symptoms to VOCs pollution will vary, depending on the level and duration of exposure.

Right now, we know very little about the health effects of many organic compounds found in our homes.

What Can You Do to Fight Indoor Air Pollution?

The first thing you can do is to limit your exposure to the things that are causing the problem.

When it comes to allergens you can try to remove dust, pet dander, and mold from your home.

With volatile organic compounds there’s no way to get rid of all of them but there are things you can do to limit your exposure.

  • To limit your exposure to VOCs you may have to change your buying habits. Try to avoid products that have a strong smell or a lot of fragrances added.
  • Use biodegradable cleaning products.
  • Use house products according to the directions of the manufacturer.
  • If you are painting or changing carpeting in your home there are low VOC options available today.
  • Purchase only the quantities you are going to use immediately.
  • Get rid of the little-used or unused containers.
  • If you have to use pesticides or paint thinners try to do so in a well ventilated area, open up the doors and windows of your home to get fresh air from outside.
  • Don’t mix household products unless clearly directed on the label.
  • Keep any containers of these products away from reach of children or pets.

Trying to remove the source of indoor air pollution is very important but it’s simply not possible to remove all of the potential sources so the next thing we can do is to try to eliminate whatever pollution is left over after we have made an effort to reduce our exposure in the first place.

hepa filter in purifiers and cleaners
Using HEPA to eliminate airborn pollution

A great way to reduce indoor air pollution is to use air purifiers. An air purifier with a HEPA filter will effectively eliminate 99.97% of the common allergens from the air in our homes.

Volatile organic compounds require an additional step. A HEPA filter can remove airborne particulates down to 0.3 microns in size but even this is not small enough to filter out VOCs.

In order to remove VOCs from the air in our homes we need an air purifier with an activated charcoal filter. The activated charcoal will chemically bond with VOCs, eliminating them from the air we breathe.

Indoor air pollution is a huge problem but there are steps we can take to greatly improve the quality of the air in our homes. An air purifier that has both a HEPA filter and an activated charcoal filter is a great way to make sure the air you are breathing a safe.

Other Causes of Indoor Pollution


Mold can be a serious problem. It usually occurs in bathrooms, wet basements, close to leaky sinks and leaky roofs. It may develop under wallpaper, or around air conditioners.

It is important to deal with mold because there is a serious health risk involved, like respiratory irritation, asthma symptoms, increased sensitivity, brain fog, performance problems, and overall health deterioration (especially after long-time exposure).

Don’t take this lightly. If not convinced how serious the problem can be, watch the excellent Moldy movie.

Dealing with mold includes addressing the origin, which in most cases means getting rid of the moisture. You can do that on your own by scrubbing the mold and throwing away the carpets or furniture. That is if mold occupies no more than 10 sq. feet, but for larger areas you should hire a professional.

Another factor that you should keep an eye on is the indoor humidity. Keep it low, preferably under 50%.

A lot of houses with poor foundation may develop mold problems over time. Make sure that you address this problem, otherwise you will constantly be at risk of mold pollution.

Dust Mites

These tiny creatures are natural inhabitants of your home, living in fabric, dust, bedding, carpets, and furniture. They find their nutrition in dead skin cells, and need warmth and moisture to survive. Their waste products may trigger allergies, rashes, and asthma attacks.

Regular washing bed linens and allergen blocking bedding may help deal with dust mites. Using HEPA filters in air purifiers and vacuum cleaners also help a great deal.


asbestos material
Asbestos as building material

Asbestos is basically a type of mineral fiber. It has been used in some building materials, especially in the past for its excellent strength and high temperature resistance. Asbestos is proven to be a hazardous material for human health. Despite its bad reputation, it is not entirely banned in the United States, so you should be careful if you are buying a new home.

Most HEPA filters are capable of trapping asbestos airborne particles, which measure around 0.3 microns. For your living space to be completely asbestos-free it is advisable to keep your air cleaner running a longer period of time.


Lead is a very persistent pollutant. It has been present in our soil for decades.

Lead based paint was used before 1978. If your house or apartment is old, there is a chance that it has lead paint. It is important to eliminate (not just repaint the old paint with new lead free paint) this type of paint entirely from your house.


Children are susceptible to lead poisoning above all other age groups of population. In houses positioned in the vicinity of highways, airborn lead is also a huge problem.

Besides highways, other sources of lead can be industrial emission, aviation fuel, and batteries. The lead levels in the air may fluctuate with seasonal and industrial activity.

For young children, the U.S. CDC is lowering the threshold for lead poisoning.

As most lead particles range from 0.4 to 10 microns in size, HEPA filters are excellent at reducing indoor levels of lead.


Radon is an invisible radioactive gas. It has no color, no odor, and can be detected only with radioactive testing. It occurs as a byproduct of radioactive decay in almost all soils.

Air purifiers won’t help much in the case of radon contamination. The best way to deal with this gas is to prevent radon from entering your home in the first place.