Why is Indoor Air Quality such a big concern today?
One of the most frequently quoted statements in the air purification industry is that indoor air quality (IAQ) can be 2 to 5 times more polluted than outdoor air, a statement made by the EPA. A major contributing factor to this is that modern construction techniques have created houses and other buildings that are more airtight. Better sealed homes may reduce our heating and A/C bills, but they also trap in pollutants by reducing ventilation.
Another major reason that IAQ is such a big concern is that many common products release dangerous chemicals into our homes. This was less of an issue in the past because research had not yet been done showing the dangers of these chemicals. Now that we know that the dangers exist, a major modern concern is how reduce them.
What is an Air Purifier?
An air purifier is a device that is used to remove pollutants from the air. They come in all sizes and shapes for hundreds of different applications. There are several technologies used in air purification .When discussing air pollutants, the topic is generally broken down into two broad categories: chemicals (also referred to as gases) and airborne particles.
A third category sometimes mentioned is odors, though in truth, when we smell something what we are doing is inhaling a gas; thus odors are caused by chemicals and are removed the same way.
Airborne Particles
These come in a variety of shapes and forms from many sources, and encompass dust, pollens, mold, hair, pet dander, bacteria and viruses.
Chemicals/Gases
Gases constantly surround us and are essential to life on Earth. Our air is a mixture of gases including oxygen which we must breathe to live. However, there are gases that can be dangerous, even lethal to breathe, and these are the gases that an air purifier can be used to negate. Gases come from many man-made sources, both industrial and residential. Some common examples
include formaldehyde in new carpeting and the many chemicals in cleaning products. Some gases that exist naturally can also pose serious health risks, such as radon gas. Gases are also the source of odor
Who needs an Air Purifier?
That question is difficult to answer; it’s a bit like asking “Who needs to exercise more?” Everyone breathes dangerous chemicals and particles every day, and thus everyone could use an air purifier. However, some people are far more at risk than others, and these people will feel more of the positive effects of breathing cleaner air.
This group includes, but is certainly not limited to, the following people:
· People with asthma or other respiratory diseases and/or allergies to mold, dust, pollens or pet dander
· People who suffer from chemical allergies, chemical sensitivities, are irritated by odors, or have MCS (multiple chemical sensitivities)
· People who are immuno-compromised and are more susceptible to bacterial or viral infections (such as HIV patients)
· Anyone who works with dangerous airborne substances. Many professions fit under this umbrella including manicurists, welders, artists and laboratory workers.
· Those whose homes or offices have a radon contamination problem
However, the dangers presented by many common household chemicals are not fully known. Research has shown chronic exposure of very low doses of certain common household chemicals may be harmful to infants. Yet research in this field is relatively new (much of it has been done in the last 10 years) and there is still much to learn. What is known is that there are thousands of chemicals in varying amounts in every home. Because we simply do not know what dangers are posed by every chemical, it is difficult to answer the question of who needs an air purifier. Overall, though, breathing cleaner air is the healthiest choice for everyone, and that is what an air purifier provides
Air purifier is a good thing to have for when baby (or you) gets sick or stuffy.
I would suggest you get one if there is a history of asthma or allergies in your family, if you have pets, if anyone in the household smokes (even if they go outside to do it), if you’re not planning on breastfeeding and if you don’t have an air purifier.
My son and I lived with my parents until my husband and I got married, when baby was 15 months. I had an air purifier in our basement bedroom, in a house with 4 pets, and a history of allergies and asthma. We ran the air purifier all the time to help clear the air .
-Maria K. Toronto
Technology
Ozone-emitting purifiers are dangerous.
There are several different air purification technologies available on the market today. One of these, purification with ozone, is actually dangerous to human health but many regulatory agencies are incapable of doing anything about it even though they know of the dangers.
Here is a brief description of the most widely used technologies in air purification today. Included is a discussion of their safety and their effectiveness.
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· Activated Carbon
· HEPA Filter
· Ion Generators
· Electrostatic
· UV Light
· Ozone-emitting technology
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Activated Carbon
Activated carbon is the most effective chemical filtration technology. It is an extremely porous substance; the surface area of one gram of activated carbon can be thousands of square meters. As chemicals pass over the activated carbon, they are “adsorbed”, a process in which chemicals bond to the surface of the carbon. Once the chemicals are bonded to the carbon, they have been filtered and removed from the air. Carbon is part of every living organism on earth, and the carbon used in air purifiers can be derived from many different sources such as peat moss, anthracite coal or coconut shells. Different carbon sources have slightly different chemical properties, making specific blends of carbon more effective for individual chemicals. Carbon doesn’t filter out every gas in the air (for example it leaves it the oxygen) but it is the most tried-and-true chemical filtration technology. Respirators (gas masks) used by the military use activated carbon.
The effectiveness of carbon filters are based on two main factors. First, the amount of carbon used is important. Many purifiers truthfully claim to use activated carbon, but they only use it in a very small amount which will quickly lose its effectiveness. Also, dwell time, the time that the air spends passing through the carbon, influence the effectiveness of the filtration process. The depth of the carbon filter (deeper filters add dwell time) and the speed of the motor (slower speeds add dwell time) are the main factors that affect the dwell time.
Carbon filters must be replaced occasionally; for the average home it is about once every two years, though in highly chemical industrial environments it may be more frequently. Overall, carbon filtration is the only mainstream and safe method for gas removal, and it is highly effective. It is an inert substance and is safe. A carbon filter does not remove particles, though it is generally coupled with a HEPA or other particle filter in most air purifiers.
HEPA Filter
Short for high efficiency particle arresting filter, HEPA is the most common particle filtration technology used in the air purification industry. Developed in the 1970s by the US Department of Energy, today it is the standard filter used in clean rooms, hospitals and laboratories. A HEPA filter, by definition, is 99.97% effective at removing particles of 0.3 microns in size. However, the true effectiveness of the HEPA filter is dependent on how it is installed.
This is the reason that some air purifiers claim different effectiveness ratings despite the fact that they are using the exact same filtration material. The biggest factor influencing the effectiveness of a HEPA filter is the seal around it. If air can bypass the filter by seeping around it, it is not going to get filtered properly and the “99.97% effective” rating can decrease considerably. Also, the way the HEPA is rolled and pleated influences its effectiveness. HEPA should be rolled when it is warm to eliminate cracks (it is a glass-based material) and should be evenly pleated to make sure that the air does not go through a single part of the filter more than any others.
In an average home environment, a HEPA filter must be replaced approximately every 5 years. Overall, a HEPA filter is extremely effective at removing all airborne particles including mold, dust, pollen, bacteria and viruses (a properly installed HEPA filter is still extremely effective at filtering particles smaller than 0.3 microns, which most viruses are). A HEPA filter is not designed for filtering gases. In some air purifiers it is used along with a carbon filter so that the total air purifier filters gases and particles. It is a safe technology.
Ion Generators
Ion generation technology releases positive or negative ions into the air that charge airborne particles and make them cling to nearby surfaces like walls and chairs which removes them from the air. This is a viable method for particle removal, though the process is not standardized. This makes it very difficult to judge the true effectiveness of the many products that are on the market. Also, many ion generators release a small amount of ozone which is toxic. Ion generators do not remove gases (or odors) at all. Because of this, some ion generators are coupled with ozone-emitters and these are dangerous. Overall, ion generators do have some effectiveness for airborne particle removal, but their effectiveness varies and they don’t remove chemicals/gases.
Electrostatic
These air purifiers use charged plates to attract and trap particles that pass by them. Generally, a fan pulls the air into the purifier. By giving the particles a static charge, the charged particles will stick to the plates in the electrostatic purifier. For particle removal, an electrostatic purifier is quite effective. The two major downsides of this type of purifier are the lack of chemical filtration and the regular maintenance; an electrostatic filter does nothing to eliminate gases or odors, and the charged plates must be cleaned frequently. Overall, an electrostatic purifier is effective for particle removal and ineffective for gas removal. It is a safe technology.
UV Light
Short for ultraviolet light, UV can be used as an anti-microbial filtration technique. UV light breaks down the DNA of microbes (such as bacteria, viruses and mold) and makes it so they cannot replicate. This neutralizes them, rendering them harmless. In most air purifiers that are equipped with this technology, the UV bulb is inside of the housing. If it is properly housed inside the purifier, UV technology is safe. People should not stare at a UV bulb for an extended period of time.
Ozone-emitting technology
Ozone (O3) is a chemical made of three oxygen atoms. It is an unstable molecule and it is due to this property that it is used in air purification. The ozone will react with other chemicals, changing their molecular structure.
However, according to the EPA, “Available scientific evidence shows that at concentrations that do not exceed public health standards, ozone has little potential to remove indoor air contaminants.” This means that to be effective at removing chemicals or preventing bacterial or mold growth (two uses of ozone) the amount of ozone that would need to be used would be dangerous to humans. Thus, ozone purification is either dangerous or ineffective. Also, ozone does not remove airborne particles such as dust or pollen. To read more on what the EPA has to say about Ozone-emitting air purifiers.