Portable air cleaners may employ a combination of filter types discussed above and are usually small units that can be moved from room to room. The effectiveness of portable air cleaners is measured by the clean air delivery rate (CADR) which was developed by the Association of Home Appliance Manufacturers (AHAM) and measures the volume, in cubic feet, of filtered air that the filter delivers per minute. The CADR rating lists three numbers -- one for tobacco smoke, one for pollen and one for dust. The higher the tobacco smoke, pollen and dust numbers, the faster the unit filters the air. AHAM www.cadr.org recommends that consumers apply a 2/3 rule: look for a unit with a tobacco smoke CADR at least 2/3 of the size of your room’s area (cubic square footage), and if the ceilings are higher than 8 feet (typical in brownstones) choose a unit rated for a larger room. The EPA notes that most portable air cleaners currently on the market do not have high enough CADR values to effectively remove large particles such as pollen, dust mite, and cockroach allergens. Some portable air cleaners using electronic air cleaners might produce ozone, which is a lung irritant as described above.

Cleaning air the natural way: PLANTS In the book How to Grow Fresh Air  the NASA scientist B.C. Wolverton described his research into creating a healthy, breathable environment for a space station and his resultant discoveries that house plants, including those as humble and easy to grow as the tulip and Boston fern, are excellent air filters and remove some of the most ubiquitous offenders found in households today, including ammonia, formaldehyde, and benzene. He also rates each plant for its effectiveness in removing various pollutants, and its ease of growth and maintenance.

Stop germs and chemicals at the front door. Adopting the simple custom of removing street shoes upon entering the home in fact eliminates the introduction of hundreds of chemicals and biological pollutants into your home environment. It follows that wiping down Rover’s paws after a jaunt around the block (not to mention other body parts if your pooch shares the furniture with you) has the same effect.