Biologicals*

Sources: Wet or moist walls, ceilings, carpets, and furniture; poorly maintained humidifiers, dehumidifiers, and air conditioners; bedding; household pets.

Health Effects: Eye, nose, and throat irritation; shortness of breath; dizziness; lethargy; fever; digestive problems. Can cause asthma; humidifier fever; influenza and other infectious diseases.

Levels in Homes: Indoor levels of pollen and fungi are lower than outdoor levels (except where indoor sources of fungi are present). Indoor levels of dust mites are higher than outdoor levels.

Steps to Reduce Exposure:

• Install and use fans vented to outdoors in kitchens and bathrooms.
  
  
• Vent clothes dryers to outdoors.
  
  
• Clean cool mist and ultrasonic humidifiers in accordance with manufacturer's instructions and refill with clean water daily.
  
  
• Empty water trays in air conditioners, dehumidifiers, and refrigerators frequently.
  
  
• Clean and dry or remove water-damaged carpets.
  
  
• Use basements as living areas only if they are leak-proof and have adequate ventilation. Use dehumidifiers, if necessary, to maintain humidity between 30-50 percent.

* From www.epa.gov