Opinion: There are some serious health implications from breathing in the air of a home that has been sealed up to be more energy-efficient.

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Nowadays, people are spending longer than ever indoors, around 22 hours a day in fact. The majority of this time is likely to be in your workplace and home. We have heard for many years that we must make our homes more energy-efficient by sealing them up to cut carbon emissions and save money. These are clearly important issues to address, particularly because lower indoor temperatures have been found to be more linked to adverse health effects such as increased blood pressure

But what if staying warm isn't our only health consideration? No-one wants to spend their time in a sealed box, yet that is what we are doing with our homes and the implications of this can be stifling. I don’t just mean stuffy, smelly and uncomfortable - although this may at times be the case - because there are some serious health implications from breathing in the air of a home that has been sealed up.  

Air fresheners, scented candles, cleaning products and cosmetics such as nail polish remover and hairspray can seriously affect our indoor air and therefore our health. Even new furniture and the very insulation we wrap our houses with can contain indoor air pollutants such as formaldehyde, which studies have found present skin/eye irritations at low levels and may lead to the development of cancer of the respiratory tract at higher levels over time.

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We also find flame retardants (PBDEs in carpets and upholstery) and a whole host of circulatory system disrupting chemicals (EDCs) such as Phthalates in building materials, PCBs in paints and Bisphenol A in building components inside our homes. These can wreak havoc on our health by affecting our hormones, causing fertility problems, thyroid and liver issues, obesity and even affect learning and memory.

We can help prevent this by outgassing new furniture (leaving in out in a garage or shed to air out the chemicals before bringing it into your home), buying second hand or shop demonstration models and choosing your personal care and cleaning products carefully to make sure they don’t contain any nasties. We should also be researching any materials we choose to insulate and renovate with. For example, sheep's wool insulation has amazing thermal performance, can handle moisture well, absorbs and locks away indoor air pollutants and is naturally flame retardant. The downside is that products like this can cost a bit more, though you have to think about health considerations in the long run.

To create and maintain a healthy home, we must consider the main and most important activity we do there: breathing! With the exception of houses which are purpose built to be "airtight" and have a suitable ventilation/ air filtration system for return supply air, we need to actively take steps to ensure our homes are kept well ventilated.

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If you cannot afford ventilation systems as part of renovation projects, there are still things you can do to help protect yourself from poor air quality. In Denmark, the government advise people to air out their homes three times per day. This is best done at opportune times when it is not more humid outdoors than inside, before you switch on the heating or before you go out (obviously taking care to close and lock the windows afterwards!) and by choosing windows away from road traffic or nearby chimney fumes.

Thinking about the moisture balance and the house as a whole system helps. Heat and humidity are critical factors, because if we warm up air, it will be able to hold onto excess moisture generated inside the home rather than being left to cause problems. It is important to have a kitchen and bathroom extractor fan installed, and to run it when in use, for adequate time to clear any residual moisture. This is because excess moisture will travel all around your home and condense at "cold spots" such as on or around single glazed or poorly fitted windows, inside the walls or around rusted or dirty wall ties within wall cavities. It is another reason why we should think twice about drying clothes indoors as a single load can contribute around 20 litres of excess moisture looking for a new home in your building fabric!

But surely water is not going to do me any harm? Unfortunately, moisture can not only do damage to the building itself, but it also provides a key condition for mould to grow. Inhaling mould spores has been linked with a wide range of health conditions, from COPD and asthma in children to being a trigger for chronic illness or impeding recovery.

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As well as taking care about the products you bring into your home, you should also pay attention to how the combination of different materials will react together. Be careful when adding extensions or new concrete floors, for example, beside a wooden floor which is designed to be vented underneath. If you are unsure, it is best to consult a professional who will advise you about any home improvements, and how to ensure air and moisture can move freely.

While many things you can do are free - taking care how you dry your washing, airing out the house and new furniture - purchasing safer products may cost a little more. Of course, increasing anxiety around these issues in itself can adversely affect health, so it is important to not get overwhelmed and just make small changes as you go along. Ultimately, even if it costs extra to choose better products, it is better to pay with your wallet than your health.

The views expressed here are those of the author and do not represent or reflect the views of RTÉ