In your effort to combat indoor allergens, keep two other factors in mind: air filtration and indoor air humidity. With a growing number of cases of asthma in recent years occurring among children who spend much of their time inside, attention has been given to indoor air in preventing asthma symptoms.
Just finding better ways to condition the air will not serve as a sole solution to eradicating asthma triggers in your home. Probably many sources of asthma symptoms — such as dust mites — are found in heavier concentrations, for example, in and on furniture, floors, carpets, and other furnishings.
In your quest to find the best way to condition air in your home, though, you will find that there is no one-size-fits-all answer. Depending where you live, many variables need to be taken into consideration: presence of pets, pollen counts, outdoor climates, household renovations, or even wood or cigarette smoke.
Cleaning the Air
Many products on the market — such as central air furnace filters and portable filtration systems — are geared at cleaning your home's air. But keep in mind that no federal standards exist spelling out the relationship between air filtration products and improvement of health symptoms. However, standards from manufacturers and manufacturing groups are available to guide you in determining if various products could help in your quest to have cleaner indoor air (see Chapter 16).
To maintain good air quality inside your home — and help your child breathe better — many low-cost or no-cost solutions are available for you. They are:
Prohibit of any kind of smoking inside your home.
Use air conditioning — in your home and even your car — on days when the pollen or mold counts are high or when ozone or pollution warnings are issued.
When pollen counts are high, consider going outside — only if necessary — later in the morning because the counts are usually highest between 5 A.M. and 10 A.M.
When air quality is poor for the day, consider opening doors and windows — if it is necessary — in the early morning hours before pollution has had a chance to build up.
Avoid the presence of nitrogen dioxide (NO2) — an odorless gas byproduct of fuel-burning appliances such as gas stoves, gas or oil fireplaces, wood stoves, and space heaters — by making sure they are all properly vented to the outside.
Avoid using spray pesticides around the house.
Use unscented or nonaerosol household cleaning products, while avoiding scented candles, powdered carpet cleaners, or room fresheners.
Remember to change your central air and portable air filters regularly, following the manufacturers' directions.
Humidifying the Air
Data from the National Survey of Lead and Allergens in Housing indicates that the strongest independent predictor of dust mite allergen levels is indoor humidity. It found that homes with relative humidity above 60 percent have three to four times higher mean bed dust mite allergens than homes with relative humidity below 60 percent. This increased relative humidity also was associated with higher levels of cockroach and mold allergens in the home.
For personal comfort and a healthier environment, the ideal relative humidity in your home should fall between 35 percent and 50 percent. Consider using a digital hygrometer, a simple device that can be purchased in hardware or other retail stores that measures indoor relative humidity, to determine the level throughout your home.
Generally, only use a humidifier in your home only when conditions require it — such as when the relative humidity drops below 35 percent and the air is very dry — such as during cold weather or in certain parts of the country such as the Southwest. This dry air could irritate your child's throat and airway linings. Remember to use the correct moisture setting for existing conditions and to clean any unit thoroughly