Many biological contaminants are present in our homes and work spaces. Indoor pollution occurs in different forms whichinclude bacteria, viruses, animal dander and cat saliva, house dust, mites, cockroaches and pollen. By controlling the relative humidity level in a home, the growth of some sources of biologicals can be minimized. A relative humidity of 30-50 percent is generally recommended for homes. However, in our country the prevailing temperature and humidity conditions promote the amplification of a lot of these antigens.
Standing water, water-damaged materials or wet surfaces also serve as a breeding ground for molds, mildews, bacteria and insects. House dust mites, the source of one of the most powerful biological allergens, grow in damp, warm environments.Contaminated central air handling systems can become breeding grounds for mold, mildew and other sources of biological contaminants and can then distribute these contaminants through the home. Many of these biological contaminants are small enough to be inhaled and subsequently lead to a number of health related problems.
Some biological contaminants trigger allergic reactions, primarily -hypersensitivity pneumonitis, allergic rhinitis, some types of asthma.Infectious illnesses, such as influenza, measles and chicken pox are transmitted through the air. Molds and mildews release disease-causing toxins. Symptoms of health problems caused by biological pollutants include:sneezing, watery eyes, coughing, shortness of breath, dizziness,lethargy and fever.
Children, elderly people and people with breathing problems, allergies, and lung diseases are particularly susceptible to these ill biological agents in the indoor air.
Reducing Exposure to Indoor Biological Contaminants
General good housekeeping, and maintenance of heating and air conditioning equipment are very important. Adequate ventilation and good air distribution also help. The key to mold control is moisture control. If mold is a problem, clean up the mold and get rid of excess water or moisture. Maintaining the relative humidity between 30% – 60% will help control mold, dust mites and cockroaches.
- Install and use exhaust fans in kitchens and bathrooms and vent clothes dryers outdoors
These actions can eliminate much of the moisture that builds up from everyday activities. There are exhaust fans in the market that produce little noise which is an important consideration for some people. Another benefit to using kitchen and bathroom exhaust fans is that they can reduce levels of organic pollutants that vaporize from hot water used in showers and dishwashers.
- Ventilate the attic and crawl spaces to prevent moisture build-up
Keeping humidity levels in these areas below 50 percent can prevent water condensation.
- If using cool mist or ultrasonic humidifiers, clean appliances according to manufacturer’s instructions and refill with fresh water daily.
The humidifiers can become breeding grounds for biological contaminants as they have the potential for causing diseases such as hypersensitivity pneumonitis and humidifier fever. Evaporation trays in air conditioners, dehumidifiers and refrigerators should also be cleaned frequently.
- Thoroughly clean and dry water-damaged carpets and building materials (within 24 hours if possible) or consider removal and replacement
Water-damaged carpets and building materials can harbour mold and bacteria. It is very difficult to completely rid such materials of biological contaminants.
- Keep the house clean
House dust mites, pollens, animal dander and other allergy-causing agents can be reduced, although not eliminated, through regular cleaning.People who are allergic to these pollutants should use allergen-proof mattress encasements, wash bedding in boiling hot water and avoid room furnishings that accumulate dust, especially if they cannot be washed in hot water. Allergic individuals should also leave the house while it is being vacuumed because vacuuming can actually increase airborne levels of mite allergens and other biological contaminants. Using central vacuum systems that are vented to the outdoors or vacuums with high efficiency filters may also be of help.
ARJUN KHANNA, MD, DM
SENIOR CONSULTANT PULMONOLOGIST
YASHODA SUPERSPECIALITY HOSPITAL, KAUSHAMBI
On behalf of Philips