Biological Contaminants

The indoor environment can be contaminated with a variety of microorganisms such as viruses, bacteria and molds.

Major sources

• Domestic pets
• Bathroom and other damp places
• Air conditioners, humidifiers and dehumidifiers

Health effects

Both infection and allergic diseases can result:

Infection

• Virus — “flu”, common cold
• Bacteria — Legionnaires' disease, tuberculosis
• Molds — Aspergillus infection

Allergic diseases

• Molds — allergy to Aspergillus can cause asthma
• Thermophilic bacteria — can contaminate air-conditioning system or humidifiers in offices, homes and automobiles and cause hypersensitivity reaction in the lungs

How to reduce biological contaminants

• Provide plenty of ventilation in the home and office
• Maintain and disinfect the ventilation system, air conditioners, humidifiers and dehumidifiers
• Remove and discard contaminated materials such as mouldy carpets and ceiling tiles
• Wash contaminated surfaces with dilute bleach
• Install and use exhaust fans in kitchens and bathrooms that are vented outdoors to reduce humidity
• Check and correct any water leaks in the building