Biological Contaminants

What Are Biological Contaminants?
Biological contaminants are or were living organisms, such as animal dander, dust mites, cockroach parts, fungi (molds), pollen, bacteria, and viruses. They are usually invisible to the naked eye and can travel easily through the air. Biological contaminants in the home come from many sources. Some, like pollen, enter the home through open doors and windows. Others are generated inside the home. Mold and mildew are products of excess moisture in the home. Pet dander is a common allergen produced by household pets. Viruses and bacteria can be passed through the air or person to person

Where Are They Found?
Biological contaminants are in every home and it is impossible to get rid of all of them. Even a spotless home may permit the growth of biological contaminants. Two conditions are essential to support biological growth: nutrients and moisture. These conditions can be found in many locations, such as bathrooms, damp or flooded basements, wet appliances (such as humidifiers or air conditioners), and even some carpets and furniture. Some biological contaminants (especially infectious diseases) thrive and spread easily through ventilation and heating ducts.  Any place that growth conditions exist, biological contaminants can and will thrive. 

Health Effects Of Biological Contaminants
Everyone is exposed daily to biological contaminants. There is no way to escape these contaminants, even in the cleanest of homes. Contaminants can be spread by daily activities, air circulation, or through ventilation and heating ducts (like infectious disease).
Reactions to various contaminant exposure will vary from person to person.  Some people will experience no health reactions while more sensitive people may have severe symptoms. Those who are sensitive to biological contaminants may have allergic, infectious, or even toxic reactions. More common symptoms to biological contaminant exposure are watery eyes, runny nose, sneezing, nasal congestion, itching, coughing, wheezing, difficulty in breathing, headache, fatigue, and other allergic or asthmatic symptoms.  In fact, many common asthma triggers are related to biological contaminants in the home.
People who spend a great deal of time indoors; infants, children, the elderly, and those who are sensitive to biological contaminants, are especially prone to health symptoms related to the exposure of biological contaminants.

Reducing Exposure
There are many things that can be done to reduce your exposure. Make sure that clothes dryers, kitchen range hoods and bathroom fans are vented to the outside. Use these fans regularly. Replace your carpet with hardwood or vinyl flooring. Lower your humidity levels, and keep surfaces clean and dry, disinfecting if small amounts of mold are present.  If pets are creating an IAQ problem, keep them clean and out of sleeping quarters.  Raise the temperature of surfaces where moisture condenses by improving indoor circulation to that surface  and use insulated windows to prevent condensation. Finally, clean surfaces often to prevent dust build up, and wash clothing and bedding often, preferably in water at least 130 degrees Fahrenheit to kill dust mites. 

Will An Air Cleaner Help?
Air cleaning is only one of three methods of reducing pollutants in IAQ.  Removal of the source, or control of its emissions and ventilation should be addressed before air cleaning.  Then air cleaning can be used in conjunction with source control and ventilation to control IAQ.  Some air cleaners may reduce the health effects from some particles.  Under the right conditions some air cleaners will remove certain respirable-sized particle, however, there is controversy over whether air cleaners can reduce allergenic particles such as mold spores, animal dander, dust mites, and other such biological contaminates.