Biological Pollutants

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What are biological pollutants?

Common indoor biological pollutants are: bacteria, molds, viruses, animal dander and saliva, dust mites, cockroach parts, and pollens.  Biological pollutants can travel through the air and are not always easy to see.  There are many sources for these pollutants.  For example, pollens and fungi come from plants and outdoor air.  Viruses and bacteria are spread by people and animals.  Household pets are sources of saliva and animal dander.  Dust mites can grow in any damp, warm place.  Central air handling systems and humidifiers that are not cleaned well can spread fungi, bacteria, and other biologicals.

Where are biological pollutants found?

Biological pollutants are everywhere; however; nutrients and moisture are needed for biological pollutants to grow.  These conditions are found in rooms such as bathrooms or damp or flooded basements.  You can also find them in wet appliances (humidifiers or air conditioners), and even some carpets and furniture.

How do biological pollutants affect health?

The effects on our health depend upon the type and amount of biological pollution and the individual person.  Some people do not get health problems from certain biological pollutants, while others may have allergic, infectious, or toxic reactions. 

Allergic reactions triggered by some biological pollutants range from uncomfortable to life threatening, as in an asthma attack.   Some common symptoms of allergic reactions are: watery eyes, runny nose, coughing, trouble breathing or itching.  Infectious illnesses, such as flu, measles and chickenpox are also caused by some biological agents.  And some biologicals (such as certain fungi) release toxins that can hurt many organs and tissues in the body.

How to reduce health risks:

Steps to Reduce Exposure

Moisture Control

  • Fix leaks and water seepage.
  • Put a plastic cover over dirt in crawlspaces.
  • Use exhaust fans in bathrooms and kitchens.  Vent clothes dryers outside.
  • Use dehumidifiers and air conditioners.
  • Raise the temperature of cold surfaces where moisture collects.  Open doors between rooms.  Use fans and move furniture from wall corners to increase air and heat circulation.
  • Pay special attention to carpet, particularly on concrete floors.  Carpet can absorb moisture and aid biological pollutant growth. Clean moist surfaces, such as showers and kitchen counters.
  • Remove mold from walls, ceilings, floors and paneling.
  • Replace moldy shower curtains, or remove them and scrub well.

Take care of and clean all appliances that come in contact with water.

  • Have major appliances, such as furnaces, heat pumps, central air conditioners, window or wall air conditioning units, and furnace-attached humidifiers, inspected and cleaned regularly by a professional, especially before seasonal use.
  • Empty room humidifiers and dehumidifiers daily and clean often.
  • Clean refrigerator drip pans often.

Dust Control

  • Always wash bedding in hot water (at least 130˚F) to kill dust mites.  Launder all bedding at least every 7 - 10 days.
  • Use synthetic or foam rubber mattress pads and pillows.  (Use plastic mattress covers if you are allergic.)
  • Clean rooms and closets well.  Dust and vacuum often to remove surface dust.