Indoor environment and health

During the 1970s, many houses were made air tight to save energy, and houses built after the 1970s are generally extremely air tight. A common consequence of this is poor ventilation, which is assumed to be behind everything from allergies and other illnesses to so-called sick building syndrome, which can result in expensive mould damage, for example.

Today, modern humans spend about 90% of their time indoors. This is why it is especially important that we have access to good ventilation. Reports have shown that one in every ten children suffers from asthma while four in every ten have some form of allergy. Indoor air is not always the cause – but it plays a significant role.

Pollutants in the home
Air pollutants include on the one hand particulate matter such as tobacco smoke, mineral fibres and dust mites. And on the other hand gaseous pollutants such as carbon dioxide, formaldehyde and sulphur dioxide. The particulate pollutants can be kept under control with ventilation filters. It would, however, require extremely complicated equipment to cleanse the air of gaseous pollutants. The easiest way to reduce the levels of all air pollutants indoors is to quite simply regularly replace the indoor air.

Where do the pollutants come from?

The most common sources of indoor pollutants are:

• materials in the building, décor and furniture.
• tobacco smoking.
• radon from the ground or building materials.
• microbiological growth such as mould and dust mites.
• open combustion (such as from gas cookers).
• cleaning agents and the like.
• cooking.
• people and animals.
• pollutants from outside such as traffic fumes or smoke from nearby factories.

Preventing sick building syndrome
There are two easy ways to prevent problems: ensure that the ventilation functions optimally and keep the air humidity level low. High air humidity increases the risk of dust mite allergy because dust mites thrive in warm, moist environments. If the indoor air has more than 50% relative humidity, it comprises a hotbed for mould, bacteria and dust mites. They all produce substances that can be found unpleasant or that are harmful to health. Humidity is avoided by preventing evaporation. The air humidity in most houses can be kept at a reasonable level by putting lids on cooking pots, avoiding steamy showers and baths and not having too many potted plants.

If despite regulated ventilation and airing you suspect that your home has high air humidity, or you can see clear indications of this such as damp spots, rot, mould or condensation on window panes, or if you would like to arrange a “health check” for your house, contact your local chimney sweeping company or talk to the health and environment office at your municipality.

Avoid air that is too dry
Air that is too dry is not good either – especially for our health. Signs of air humidity that is too low include irritated eyes, a dry throat and a persistent cough.

When the air is too dry, we become more susceptible to infections. The small hairs in our airways, known as cilium, cannot function the way they are supposed to and our “self-cleansing process” suffers. Our immune system, which is based on antibodies and antigens, also suffers.

It can be difficult to keep track of the air humidity level, but a good place to start is to ensure that the ventilation system is clean and functioning.

Regular inspections reduce the risks
It is important that the ventilation system is regularly checked, regardless of which type of home you live in. Ventilation ducts get dirty over time and, in the worst case, can become completely blocked. Let the chimney sweep inspect and clean the system, which will reduce the risk of illness and allergy. Moreover, you will most likely sleep better at night – and feel better during the day.

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