Best Way to Improve Indoor Air Quality

The interior environment is the main place where people are exposed to the allergens that result in such common allergic conditions as asthma, rhinitis, and eczema. Many of these allergens, including animal dander and mould spores, are found in the air while others, such as mite droppings, are in carpets and bedding, but become airborne if disturbed.

In addition, the air in buildings contains other pollutants, such as the sulphur dioxide given off by burning fuel, that do not cause allergies in themselves but may make the symptoms of allergic diseases worse.

Research has shown that air inside is often more polluted than that outside. Indeed, the levels of some pollutants can be as much as 20-30 times higher indoors. These findings are even more important when you realize that most people spend between 75 and 90 percent of their time indoors.

Studies of air pollution in buildings have found the following:

• House-dust mite allergen
• Cockroach allergen
• Mould spores
• Pet dander
• Pollen
• Combustion by-products, such as carbon monoxide, nitrogen oxides, and sulphur dioxide
• Tobacco smoke
• Chemicals given off by home improvement and household products
• Bacteria and viruses
• Trace metals
• Pesticides

Pollutants – allergen or irritant?

Some interior air pollutants, such as cat dander are allergens and it is these that cause allergic symptoms. Cat dander can be very persistent and may still be found in a home several years after a cat has lived there. Other inside pollutants, such as solvents from paints, are irritants, and these may provoke or worsen allergic symptoms in some individuals who already have a lowered tolerance threshold for airborne substances as a result of their allergic condition.

High humidity is another factor affecting air quality. We all feel lethargic and uncomfortable when humidity levels are high. But more than this, if high humidity is allowed to persist for long periods, it will cause damp and rot that may affect your furniture and fittings. High humidity will also encourage the growth of mould and the spread of dust mites.

Improving interior air quality

Ventilation is the key to improving the quality of the air we breathe inside. This may mean opening windows or installing an extractor (exhaust) fan in the kitchen and bathroom, or upgrading the filter in our air-conditioning. More comprehensive action may include installing a full or half-house ventilation system. Even the choices we make when decorating and cleaning our homes have an effect on air quality.

Better air quality, which can in many cases be provided naturally simply by opening doors or windows, benefits everybody, not just those with allergies or other breathing difficulties.