Indoor air quality is a major health concern. According to the Environmental Protection Agency (EPA), pollutant levels are two to five times higher inside the home than out. These pollutants include airborne particles and particulate matter such as allergens, lung irritants, gases, toxic chemicals, and volatile organic compounds (VOCs).
Indoor air pollution contaminates the air we breathe every day. Since you draw about 9 out of 10 breaths indoors, it’s easy to see why indoor air quality is a top health concern. You typically inhale about two tablespoons of airborne particles a day.
These pollutants put stress on your immune system, which can lead to other health problems. The effects of poor indoor air quality on an individual can vary greatly based on age and relative health. However, in general, poor indoor air quality leads to allergy symptoms, respiratory problems, and weakened immune systems. Children are especially susceptible to the health risks of polluted indoor air since their lungs are smaller and they have to take more breaths throughout the day. If you experience allergy symptoms or asthma attacks in your home, you may have poor indoor air quality. Other sources of IAQ problems may include poor ventilation, lingering odors, environmental changes like recent construction, new furniture, water damage, or a new pet.
Solutions to Indoor Air Pollution
The EPA suggests three basic methods for improving indoor air quality:
1. Control the source of air pollution.
2. Improve ventilation.
3. Purchase an air purifier.
Your first step should be an attempt to control the source of air pollution. If the pollution stems from something like mold, smoke, or chemical off-gassing, it may be possible to remove it from your home; this is most effective and lasting method of improving indoor air quality. However, some indoor air pollutants, such as dust and pollen, are too pervasive, and you can’t always get rid of the sources.
Better ventilation will improve your indoor air quality if the offending pollutant is a chemical or gas. In this case, bringing fresh air into the home can be very helpful. However, many indoor air pollutants originate outdoors, so opening a window on a high pollen-count day or in a smoggy city may not be the best idea.
The third step suggested by the EPA is to purchase an air purifier. With so many types and brands of air purifiers on the market, it’s pretty easy to find one that is well-suited to your home’s particular situation. Quality air purifiers can work wonders on IAQ. However, some popular air cleaners on the market are not very effective, and many air cleaners actually exacerbate some of the very problems they are meant to cure.
Common Indoor Air Pollutants
Thousands of different chemicals and proteins may be polluting your air. The most common complaints for allergy sufferers involve airborne particles like pet allergens, pollen, dust, mold, etc. These common allergens range in size from 0.3 to 100 microns, and they are small enough to be inhaled, but they’re too large to be easily exhaled. HEPA air purifiers represent the best method of removing common allergens.
Many other common indoor pollutants are simply household odors and gases. These pollutants include things like cooking smells, tobacco smoke, pet litter, and indoor pesticides. Such chemicals and odors can aggravate allergies and asthma.
Chemically reactive gases and VOCs are also responsible for poor indoor air quality. They are found in common household products like paints, cleaning supplies, disinfectants, and new carpets. They are especially harmful for the young, the elderly, and the chemically sensitive, and they can be hazardous to your health if they are present at high enough levels, or if your home is poorly ventilated. VOCs can cause symptoms like headaches, nausea, and throat irritation, and many VOCs are known carcinogens.
How Air Purifiers Improve Your Health
A good air purifier will rid your air of allergens, odors, chemicals, and many airborne disease-causing agents. Even if you’re not sick now, if you continue to breathe polluted air, you will experience detrimental health effects in the future. Many VOCs, for example, are known carcinogens that are likely to cause cancer after continuous exposure. When you purchase a quality air purifier, you will notice the difference. The air will smell fresher, and you will breathe better and sleep better.
Air Purification Technologies
HEPA Air Filters
HEPA stands for High Efficiency Particulate Air. A HEPA filter removes airborne particles like pet dander, mold spores, and dust, capturing 99.97% of all particles 0.3 microns and larger. Out of every 10,000 particles that pass through the HEPA filter, only 3 can escape if the filter is certified HEPA. The U.S. Department of Homeland Security recommends HEPA air purifiers because they’re highest current standard in air filtration. If you suffer from allergies, a HEPA filter is a necessary requirement for an air purifier. When looking at a HEPA filter, consider aspects like the size and quality of the filter medium. Top HEPA filter brands include Austin Air, Allerair, Blueair, Honeywell, IQAir, NQ Clarifier and Amaircare.
Activated Carbon Filters
Activated carbon removes gases, odors, and toxic chemicals. Carbon is “activated” by treating it with oxygen, which opens up millions of tiny pores, creating a surprisingly large surface area. (One pound of activated carbon can have a surface area of 60-150 acres!) Chemicals, gases, and odors stick to the carbon and are adsorbed by its huge surface area, bonding to the surface through chemical attraction. The more carbon there is, the more gases and chemicals it can adsorb. Impregnated carbon has been treated with an additional chemical, typically potassium iodide or potassium permanganate. These chemicals are known as chemisorbents, and they improve the carbon’s ability to handle VOCs and chemically reactive gases.
Electrostatic filters use some kind of electrostatic charge to attract pollutants. Electrostatic precipitators are air cleaners which charge particles as they pass over an electronic cell and trap the particles on oppositely charged collector plates. The advantage of electrostatic filters is that there are no filters to replace; the disadvantage is that the effectiveness of the air cleaner decreases very rapidly as the collector plates fill up with particles. Unless you are willing to wash them frequently, electrostatic filters may quickly become ineffective. Also, some electrostatic filters may generate unsafe levels of ozone, a powerful lung irritant. The Friedrich air purifier, previously ranked as the top air purifier by Consumer Reports, uses an extremely efficient electrostatic filter.
Charged Media Filters
Another type of filter which relies on electrostatic charge is the charged media filter. Charged media filters charge particles before collecting them in a traditional filter. They can trap very small particles, since they combine a filter and a charge. They can also run more quietly and economically, since the fan does not have to work as hard to draw the particles through the filter. However, like the example above, the charged-media filters lose their efficiency pretty rapidly, and some require frequent and expensive filter changes. These types of units can emit ozone, but the better ones on the market do not. If you are going to purchase this type of air purifier, make sure that it does not emit ozone. The best air purifier in this category is the ultra-quiet Blueair air purifier – and Blueair air purifiers do not emit ozone.
Ionic Air Cleaners and Ozone Generators
Ionic air cleaners operate by drawing in particles and ionizing them (giving them a negative charge). Then the particles are released into the room, where they are attracted to positively charged surfaces like walls and furniture. Since the particles are never really collected by a filter, they stick to surfaces and make your house dirty; moreover, the particles can be dislodged and re-enter the air by simple movements like walking or sitting. Most ionizing air cleaners generate ozone, which is a documented health hazard and lung irritant.
Another type of machine sold as an air cleaner is an ozone generator. Obviously, these types of machines are not recommended. The EPA has published several documents discouraging the use of ozone generators as air cleaners. Not only do they create a health hazard by emitting high levels of ozone, but they are also ineffective at cleaning the air.
Most homes contain a variety of indoor air pollutants, including airborne particulates, allergens, household chemicals, and odors. At achooallergy.com we recommend air purifiers that combine a HEPA filter with some type of activated carbon filter; this combination will remove the widest variety of indoor air pollutants.