Indoor air quality is compromised by both biological and non-biological pollutants. Sources of biological pollutants include microorganisms, animal, insects and related organisms.

The most common biological pollutants include molds and their byproducts, dust mites, pet dander (scales from hair, feathers, or skin), droppings and body parts from cockroaches, rodents and other pests or insects, viruses, and bacteria. Due to their small size, many of these biological pollutants are airborne and easily inhaled deep into the lungs.


Health Effects From Biological Pollutants
Some biological pollutants may cause serious health problems including hypersensitivity pneumonitis, allergic rhinitis, and some types of asthma. Other health problems attributed to biological pollutants are sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fever, and digestive problems.

It is believed allergic reactions occur only after repeated exposure to a specific biological allergen. The reaction may occur immediately upon re-exposure or after multiple exposures over time.