Generation and Behavior of Airborne Particles (Aerosols), Division of Applied Technology National Institute for Occupational Safety and Health Centers for Disease Control and Prevention
The life cycle and behavior of organisms from several environmental locations including floors and elevated surfaces can become airborne and be toxic to the human body. The respiratory system is the organ in the human body most sensitive to particle exposure. Our respiratory system is efficient at removing aerosols, but if they fall within particular size ranges, are highly concentrated, or toxic, they may cause adverse health effects. They may also deposit on skin or eyes, generally only causing irritation, though more toxic effects may occur. Very small particles may pass through the skin and enter the body that way.