It is a common statistic when talking about the quality of indoor air, that we spend approximately 90% of our time indoors.
The origin of that statistic was a study by the US Environmental Protection Agency back in 19891! Since 1989, the following things have happened2:
- 1989: World Wide Web invented
- 1993: e-mail starts to take off
- 1997: Broadband starts to make an appearance paving the way for the development of remote working
- 1998: Google launched
- 1999: Wifi developed
- 2007: Facebook launched
Gaming and at home working has been transformed since this time, with massive technological progression associated with connectivity and communication capabilities. It is therefore quite likely that people are actually spending well in excess of 90% of their time indoors.
The importance of this is the nature of the contained environment of the home; in the move towards greater environmental sustainability, homes have become more energy efficient and more tightly sealed. While this provides a better environmental impact, it also means that the air in the home does not become renewed through passage of fresh air.
Another statistic that is often used is that the concentrations of some pollutants can be 2-5 times higher in indoor air; this statistic is sourced from a 1987 EPA report3. Products that can contribute to this load in the air include paints, cleaning products, synthetic building materials, furnishings and personal care products. Other sources of compounds that may affect a person’s health include mold, pet dander and other allergens such as house dust mite, cockroach, etc.
It is essential that we take steps to ensure that our indoor air environment is as healthy as possible.
Sources of indoor air contaminants
Products that can contribute to a poor indoor air environment can be broadly divided into:
- Chemical products
- Biological products
A/ Chemical Products
This includes all synthetic products that will generally contribute to chemical load in the indoor environment.
- Paint – The main indoor air impact from paint is in the form of VOCs. Volatile Organic Compounds are chemicals that are emitted from liquid and solid materials, and in particular are associated with oil based paints. VOCs can cause “Eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system”4. These side effects can cause a substantially greater problem for those suffering from asthma as it can prompt an asthma attack5. In the past decade significant steps have been taken to reduce and remove the amount of organic solvents used in paint. Unfortunately whether it be in dyes for clothing, anti-microbial compounds or solvents in paint, often the more undesirable compounds are the most effective.
- Flooring – Flooring covers a wide range of products, and your selection can have a significant impact on your indoor air quality. Positive effects of flooring include trapping dust and dirt, as well as having easy cleaning surfaces. Negative effects are predominantly based on the chemicals used in the manufacture of the flooring (phthalates, formaldehyde, biocides6,7,8,9), or of the adhesive used to secure the flooring (through emission of VOCs10). Linoleum or laminate wood flooring have been recommended for a long time for those suffering from asthma and allergies, due mainly to their low ability to retain allergens through their ease of cleaning. While this may be beneficial for some people, it is not the whole story. While carpet can retain allergen, it can therefore act as a sink for allergens. Where laminate floors may allow dust and allergen to float around, the carpet traps the allergen within the pile of the carpet11,12. Effective cleaning for both these types of surfaces is the key.
Cleaning Products – Cleaning products are a necessary part of life, and are important to maintain a healthy indoor environment through the removal of dirt and dust. Even the most eco-friendly, inert cleaning product contains chemicals. What is important is the type of chemical and how much of it is in the product. Chemicals that may contribute to a poor indoor air environment include:
In discussing cleaning products, it is important not to confuse environmentally friendly with human friendly. Environmentally friendly cleaners will often use natural essential oils as an active ingredient however these oils can elicit an allergic response in sensitive individuals13,14.
- Tobacco smoke – Environmental tobacco smoke has been clearly defined as contributing to ill health and the 2006 US Surgeon General’s report on this subject states that environmental tobacco smoke is a cause of premature death. Those living with a smoker have a 20-30% increased of risk of lung cancer and a 25-35% increased risk of coronary artery disease15.
- Asbestos – Asbestos has been identified as a cause of lung cancer. It was used as an insulation product, and while it has been tightly regulated since the 1970s it is still used in a variety of products in the United States including roofing products, fireproof clothing and brake pads16.
B/ Biological Products
There are a range of biological compounds that can contribute to a poor indoor air environment. These are predominantly allergens and include:
- Animal Dander
- House Dust Mite
Mold is ubiquitous in the environment and can grow quickly in moist humid conditions. It can cause particular problems in kitchens and bathrooms and any mold growth should be addressed quickly as it can affect both the integrity of the surface it is on, as well as potentially causing health problems.
Allergens from animal dander, house dust mites, cockroaches and pollen are generally only a problem for those who suffer from asthma and allergies and generally won’t cause health issues for anyone else.
Health Impacts of Poor Indoor Air Quality
Indoor air quality can sometimes be quite an intangible thing to measure as a consumer and while poor air quality can be difficult to detect in the home, its impacts can be quite severe. Symptoms of poor indoor air quality can include17:
- Trouble breathing
- Runny/stuffy nose
- Dry/itchy eyes
- Skin rash
Addressing the health impacts of poor indoor air quality is important. In addition to the physical effects outlined above, there is a significant financial cost. A study in France in 2014 attempted to illustrate the cost of poor indoor air quality. While not a purely quantitative study, the authors of this study estimated that the cost to France of poor indoor air quality was €19 billion per year18. The United States is 18 times bigger than France with a population four times its size19.
Prevention is cheaper than treatment
While established structural and contamination issues can be difficult and expensive to address, there are steps you can take to either prevent them from happening or to mitigate their impact. It is the synergy of these steps that can have the most positive impact on indoor air quality.
- Paint – In the past decade significant advances have been made with paint products to establish low- or no– VOC paints that have comparable functionality and efficacy to ‘standard’ paints. These paints that have a more positive impact on indoor air quality, through their lower VOC levels, are predominantly water based20. Some ranges of paints may also include anti-bacterial and anti-fungal compounds, helping to prevent biological contamination in the indoor environment.
- Flooring – VOCs can be emitted from the adhesive used to secure flooring and so in a similar way to paint, low or no VOC alternatives should be used wherever possible. Linoleum floors can be easier to clean, however carpeting can ‘trap’ dust and some allergens and therefore prevent their aerosolization. Selection of the right type of flooring can help to reduce allergen and dust load in the air, as well as reducing VOC levels.
- Cleaning Products – Cleaning is an essential part of maintaining a healthy indoor air environment. However it can be a double edged sword. If too much cleaning product is used, an increased chemical load can be introduced into the environment, if not enough is used cleaning can be ineffective. In order to help to balance this, products should be selected that are less impactful on the indoor air environment.
- Air Cleaners – Air cleaners or purifiers play an essential role in maintaining a healthy indoor air environment. Selection of the right air cleaner can have a significant impact on the load of the indoor air environment. Bacteria, mold spores, pollen and other allergens can all be removed with an effective air cleaner system; carbon filters can remove tobacco smoke, odors and some chemical compounds. Choosing the appropriate effective filtration technology is essential – filter efficiency, size of room, outdoor environment and alternative technologies are all things that need to be considered21.
- Vacuum Cleaners – A vacuum cleaner is also a key part of maintaining a healthy indoor environment whether you have laminate or carpeted flooring. Using a brush on laminate flooring can aerosolise dust and particulate matter, and should be avoided. Not all vacuum cleaners are created equal and there a number of characteristics that should be assessed when purchasing or using a vacuum cleaner. As outlined above, carpet can be a good choice for a healthy indoor environment, however it must be cleaned effectively; a vacuum cleaner should be selected based on its ability to do this.
- Dehumidifier/Humidifier – Humidity plays an established role in indoor air quality; if humidity is too high, mold and dust mite growth will be encouraged, if it is too low the mucous membranes can become irritated. In order to maintain a healthy indoor air quality, relative humidity should be controlled between 40-50%22; an effective humidifier or dehumidifier can be helpful in this maintenance.
Ensuring a cohesive and effective approach to indoor air quality requires a multifaceted approach, and one that those suffering from asthma and allergies can be very familiar with. Where people are sensitive to particular triggers, which can either be biological or chemical, they often have to take extra precautions to try to control this exposure. This approach can be daunting for a consumer to address as there are many sources of contamination to consider, and many potential solutions. Many of the products aimed at establishing an effective allergy control plan, are by definition also improving your indoor air quality.
Certification marks can be a good signpost for a consumer to follow, to identify products and services that may assist in maintaining an asthma and allergy friendly home, and therefore a healthy indoor environment. Consumers should still educate themselves fully on what their individual requirements are, however third party direction can be helpful in this.
There are a number of Certification Marks that are established to deal with the chemical element of healthy indoor air, such as:
- California Air Resources Board23
- Scientific Certification Systems – SCS Indoor Advantage Gold25
asthma & allergy friendly®– The asthma and allergy friendly® Certification Program is operated by Allergy Standards in collaboration with the Asthma and Allergy Foundation of America (AAFA), Asthma Canada (AC) and is also operated internationally through a global certification mark. The program certifies a range of consumer products that they are more suitable for those suffering from asthma and allergies, based on their impact on indoor air quality. Their certification addresses both chemical and biological contaminants, as well functionality of the products.
All food and drink that enters your body is tested to ensure that it is safe for consumption. A human could last up to 3-4 days without water27, and just 3-4 minutes without air28. This is how important air is to us, and yet the food and drink we consume is tested to a much higher level than the air we breathe at home.
Taking some proactive steps to improve your indoor air quality is a way to ensure that you keep this fundamental life support as clean as possible. You should always educate yourself as fully as possible as to your own needs in terms of maintaining a healthy indoor air environment. Selection of products to support your indoor air quality can be difficult, however selection of products that are certified asthma & allergy friendly® is certainly a step in the right direction.
About the author
Thanks to Dr. Tim Yeomans for this insightful article.
Dr. Tim Yeomans is the Centre Manager for Shannon Applied Biotechnology Centre, a collaboration between two third level colleges in Ireland. Tim holds a PhD in Microbiology and postgraduate qualifications in Technology Commercialisation and Innovation Management. Tim has worked in research and development for 20 years, both in industry and academia. In his role in Shannon ABC, Tim is responsible for the scientific direction of the Centre, intellectual property management and business and technology development.
asthma & allergy friendly®, indoor environment, allergy, asthma, certification, allergy insights, healthier home, indoor air quality.
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