Wherever we live, there may be harmful substances in the air. Poisons in your own living room? The very idea is enough to make you feel queasy! But here’s the good news: with proper ventilation and a few behavioural tips, significant improvements are possible.

Children are especially sensitive to toxins within the home. So be sure to be critical when buying furniture or other materials. (Image: fotolia)

Healthy living and breathing clean air is a big topic. For example, babies or toddlers who only infrequently venture outdoors may spend 8,000 or even 9,000 hours inside their home each year. But even other members of the household who go to school or work during the day also spend countless hours indoors.

Healthy living: time for action!

So how healthy (or unhealthy) is the air that we breathe every day? “Certain problems have been accentuated,” says Zurich-based environmental chemist and building ecologist Reto Coutalides, who specialises in indoor air and ecological building. He is also the author of the book “Indoor climate — creating healthy buildings”.

In the case of building renovations, building envelopes have greatly improved in terms of insulation over the years. Combined with better windows, many buildings today have a high degree of airtightness. The result is that toxins within the home have fewer opportunities to escape outside. If the interior spaces are insufficiently ventilated, the CO2 concentration increases. In addition, there are often moisture problems and a build-up of mildew. Some toxins, which are found in certain materials or furniture, occur in higher concentrations if there is insufficient ventilation.

More fresh air!

Proper ventilation is not difficult to achieve, however it requires a certain amount of discipline:

  • It is best to let in a proper draft four to five times a day for about five minutes (so-called intense ventilation). This is much more efficient than just opening one or two windows halfway, or even just tilting the windows.
  • It becomes more difficult if you are either not at home during the day or only at home for a short time. Unless you ventilate the bathroom after showering in the morning, you will have to deal with moisture and mildew. Many management companies and homeowners therefore equip their buildings with automatic, controlled ventilation systems.

The temperature and humidity also play a major role in ensuring a pleasant indoor climate. What is perceived as comfortable differs from person to person and depends on how the room is used. In bedrooms, you can set the thermostats lower without a problem. But in the living room, which is often used for sitting and reading, most people will set the temperature a little higher. When it comes to humidity, around 40 to 60 per cent is usually ideal.

Healthy living: A harmonious interior design and the fragrance of fresh flowers are wellness for the soul. (Image: fotolia)

Most people find humidity levels that are either very high or very low unpleasant. High humidity carries the risk that moisture will condense in cool places — this moisture is conducive to the formation of unhealthy mildew.

Healthy living: Dos and Don’ts

Purely from a building physics point of view, the relationships in the indoor climate are complex. In some buildings, there may be several unfavourable factors, as expert Reto Coutalides explains: “The use of humidifiers can sometimes be tricky.” For example, in an older residential building, whose shell and windows are not too dense, a relatively large amount of humidity escapes with the warm room air in the winter. The room air may then become unpleasantly dry. However, even if the occupants run a humidifier day and night, it will probably not improve very much. Coutalides warns that “because the surfaces of the walls in houses with poor insulation are rather cool, there is a risk of mould growth.” It is therefore crucial to measure the important parameters such as temperature and humidity. Often, retrofitting is the only choice and it may be necessary to commission an architect or other specialist to develop a ventilation concept.

Fresh paint? Pay attention to eco-labels and tolerance. Organic solvents in paints and varnishes pollute the indoor air. (Image: fotolia)

Do you want to live healthily and be able to take a deep breath at home? As a tenant or resident, you generally have some latitude when it comes to creating a good indoor climate yourself. Apart from ensuring proper ventilation, the following points are important:

  • Avoid fine dust inside dwellings. Measurements have shown that the concentration of harmful particulate matter indoors is sometimes higher than outdoors. For example, smoking indoors is a real no-no. Also, candles (including scented ones) are more harmful than many people realise. Most scented candles contain quite a cocktail of synthetic fragrances that many people cannot tolerate. Candles also generate CO2 and soot (fine dust).
  • Ensure healthy living by choosing the right products. When purchasing furnishings, furniture, textiles, carpets, etc. pay attention to the labels and eco-labels. Just because something has a strong and unpleasant odour, this is not a scientific basis for discarding it. But prioritise products that do not contain plasticizers, solvents and preservatives. In traditional architecture, there are many materials that are ecologically beneficial.
  • Live healthily — when building or remodelling, pay attention to building ecology. For example, clay and gypsum can absorb and release a lot of moisture. “As a rule, mineral building materials have very low emissions,” explains Reto Coutalides. Yet another example: furniture made from solid wood is not only sturdy and looks beautiful, it also does not emit toxins into the environment.

Always try to use natural and safe substances. Do you really need to “perfume” the entire apartment with a scented candle after a day at work or when enjoying a bath? Is it really necessary to burn candles for hours each day at Christmas time? The pollutants emitted by burning candles also depend on the length of the wick and the draft. The shorter the wick and the calmer the air, the less harmful the substances escaping the flame will be.

Open fires and candles, scented candles in particular, pollute the indoor air. (Image: fotolia)

There are many completely natural, alternative ways to create fragrances that promote well-being — try a bunch of flowers, fir branches, mandarins or oranges dressed with carnations.

Radon: silent danger

Radon is a radioactive pollutant whose health risks are still often underestimated. It is a decomposition product that occurs everywhere in the ground and emits radiation, and is particularly insidious because you can neither see nor smell it. According to the Swiss federal office for public health (Bundesamt für Gesundheit (BAG)), radon increases the risk of lung cancer. According to official figures, around 200 to 300 deaths per year are attributable to radon.

Anyone wanting to know the level of radon exposure within their own four walls should take some readings with a so-called “dosimeter”. Specialists and points of contact can be found via the respective cantonal authorities or the Swiss federal office for public health: www.ch-radon.ch

Because the authorities and health experts consider the risk of radon to be serious, a new, stricter benchmark for radon levels will be introduced in Switzerland on 1 January 2018. It is important to identify potentially harmful exposure by taking measurements or, if necessary, involving qualified specialists. Ultimately, this hazard can be eliminated in residential buildings via specific, structural measures or a “radon renovation” (if necessary).



Reto Coutalides: “Interior climate”, Werd Verlag, Zurich, approx. 49 Swiss francs.