| As notorious as the most commonly known | | | | Which type of air purifier really works best? |
| airborne irritants are, they are not the most | | | | There are four basic types of air purifier |
| damaging threat to your health. Neither pollen, | | | | dominating today's market; HEPA filters, |
| dust mites, nor pet dander pose the same risk as | | | | electrostatic precipitators commonly called ionic air |
| ultra-fine lung penetrating particles. | | | | purifiers, negative ion generators and ozone air |
| Most of the irritants and allergens you may be | | | | purifiers. How does each one rate against |
| familiar fall into the category of coarse airborne | | | | ultra-fine particulates? |
| particulates. That is , they are in the 2.5 to 10 | | | | First, let's reject ozone generators entirely. |
| micron size range. | | | | Studies have shown reactions with pollutants in |
| Coarse particulates usually become trapped in the | | | | the air actually produces even more ultra-fine |
| nose and throat causing sinus irritation and | | | | particulates. Add the widely recognized respiratory |
| allergies. That's certainly reason enough to want | | | | irritation and lung damage ozone can cause and |
| rid of them and many an air purifier can serve | | | | you have every reason to reject them. |
| that purpose. | | | | Negative ion air purifiers also pose risks. Both the |
| But more than 90% of all particulates are 0.3 | | | | EPA and the American Lung Association believes |
| micron or smaller in size. These can enter deep | | | | particulates that have been ionized have an |
| into the lungs, depositing in the alveoli. Particles | | | | increased chance sticking to your respiratory |
| smaller than 0.1 micron can traverse the lung | | | | system. This makes matters worse. |
| membranes and enter the bloodstream. These | | | | Ionic air purifiers produce ozone, bringing up the |
| are the most toxic of all and not every air purifier | | | | problems mentioned earlier with ozone generators. |
| will combat them effectively. | | | | They can remove ultra-fine particles and are |
| What are the health risks of lung penetrating | | | | often advertised as effective on particles as small |
| particles? | | | | as 0.1 micron. This results in marketing claims of |
| Lung penetrating, ultra-fine particle pollution | | | | "better than HEPA." Unfortunately, they are only |
| diminishes lung function, causes greater use of | | | | about 80% efficient at best, have dismal air flow |
| asthma medications, emergency room visits and | | | | rates and can lose more than 80% of their |
| hospital admissions. | | | | cleaning capacity in as few as three days due to |
| The latest studies link them to health effects like: | | | | buildup on their collector plates. They are not your |
| - Death from respiratory and cardiovascular | | | | best choice. |
| causes, including strokes | | | | That leaves HEPA filter air purifiers. As you're |
| - Increased heart attacks | | | | likely aware, they are prominently advertised as |
| - Inflammation of lung tissue | | | | 99.97% effective on particles as small as 0.3 |
| - Increased hospitalization for cardiovascular | | | | micron. But we need something effective on even |
| disease | | | | smaller particles. Is this a problem? |
| - Increased emergency room visits | | | | A misunderstood point about HEPA is it is not |
| - Increased hospitalization for asthma attacks | | | | limited to 0.3 micron particles. The 99.97% |
| - Increased severity of asthma attacks | | | | efficiency rating at that size is intended to indicate |
| - Premature births | | | | HEPA's worst case performance, not it's best |
| - Slowed lung function growth in children and | | | | performance. It just so happens that 0.3 micron |
| teenagers | | | | particles are small enough and yet still of sufficient |
| - Significant damage to the small airways of the | | | | mass to negotiate their way through the filter's |
| lungs | | | | mat of fibers. All other particles, even down to |
| - Increased risk of lung cancer | | | | 0.01 micron are trapped at even higher efficiency |
| Considering the serious nature of these health | | | | rates. |
| effects it is very important when buying an air | | | | Therefore, our need to filter out particulates in |
| purifier to make sure it will filter ultra-fine | | | | the 0.01 to 0.3 micron size leaves us with HEPA |
| particulates smaller than 0.3 micron in size. This is | | | | as our only real choice. |
| why the HEPA filters have become so important. | | | | |