The Importance of Indoor Air Quality

The Importance of Indoor Air Quality

Pure air, because we care 

The International Day of Clean Air for blue skies | United Nations draws attention to the importance of air quality, both outdoors and indoors. 

The central theme for this year, ‘Together for Clean Air,’ underscores the urgent need for enhanced collaborations, increased funding, and a shared sense of duty to combat air pollution and improve indoor air quality. Given the widespread impact of air pollution across borders, all involved parties bear a responsibility to safeguard the planet's atmosphere and ensure the well-being of all through clean air. By uniting efforts across geographical and sectoral boundaries, breaking down barriers, and transcending isolated approaches, the International Day for Clean Air states we can effectively diminish air pollution, channel financial resources and investments into measures and remedies for air quality, and reap numerous advantages. 

Why indoor air quality matters

Air is essential to our existence. Did you know that everyone breathes 15 kilos of air and inhales and exhales 30,000 times daily?

Clean air is an essential, yet limited commodity on earth. Just like we drink liters of water during the day. Most people tend to associate air quality with outdoor air pollution, but air quality indoors is just as important, if not more. 

During our lifetime, we spend 90% of our time working and living indoors, be it within our homes, at the office, or other enclosed environments, so indoor air tends to be much more impactful in our lives and for our health and wellbeing.

Poor indoor air quality can lead to a wide range of health issues, from mild discomfort to respiratory diseases. The number of pollutants is elevated indoors. You might not notice it because air quality is invisible. You can’t always see, smell, or feel it, except for dust or smoke.

Some sources of indoor pollution are:

Human and animal presence and activity release dead skin cells, hair, CO2, viruses…

  • Bacteria
  • Dust
  • Cigarette smoke
  • Mold: damp homes double the risk of developing asthma
  • Volatile Organic Compounds [1]: carbon-based compounds emitted by paints and lacquers, cleaning supplies, pesticides, building materials and furnishings, office equipment …
  • Pollen and other allergens and outdoor traffic combustion from outside

All these invisible pollution particles penetrate deep into our lungs and bloodstream. 

Indoor Air Quality management, not a recent phenomenon

Indoor air pollutants are not just a recent phenomenon. Historically, sources of poor indoor air quality have included heat, combustion, people and their activities, and the buildings themselves. As soon as humans began building shelters about 20,000 years ago and started to live indoors, they actively sought solutions to enhance indoor air quality due to the existence of pollutants. The earliest indoor air quality issues may have been caused by the discovery of fire and its use inside dwellings.

The way humans have lived indoors changed throughout the ages, and over time has led to the development of various strategies for managing indoor environments. Over various eras and geographic areas, diverse systems have emerged to facilitate air circulation and uphold indoor air quality.

For instance, in ancient Egypt, homes were constructed with small windows and openings that allowed cross-ventilation to occur. In temples and palaces, they used upper-level or so-called ‘clerestory’ windows, which were positioned high on the walls to let hot air escape while cooler air entered through lower openings.

In ancient Rome, a system known as a ‘hypocaust’ was used to heat and ventilate buildings. This involved raising the floor on pillars and creating a space below it where hot air from a furnace would circulate, warming the floors and providing some degree of ventilation.

In ancient China, traditional Chinese architecture often incorporated natural ventilation principles. The design of buildings, such as the courtyard houses, emphasized cross-ventilation and natural airflow. Windcatchers, known as "bai wind towers," were also used in some homes to capture and direct air into living spaces. 

Air pollution, a health risk that can be mitigated

Air pollution poses a significant environmental threat to human health. Indoor and outdoor air pollution combined led to approximately 6.5 million premature deaths worldwide in 2016 [2]. Within developing countries, particularly in low-income communities, indoor air pollution disproportionately affects women, children, and the elderly. This is because they face higher exposure to heightened outdoor air pollution and indoor air pollution caused by the use of wood fuel and kerosene for cooking and heating. 

Air quality in general becomes even more critical when considering that more recently, in 2020, the EU-27 experienced 238,000 premature fatalities due to exposure to fine particulate matter concentrations surpassing the World Health Organization's guidelines. That same year, 96% of the urban population was exposed to levels of fine particulate matter above the health-based guideline level set by the World Health Organization [3].

Other than the wide range of health issues that it can cause, poor indoor air quality is equally linked to reduced productivity and cognitive function problems, such as decreased concentration and impaired decision-making. In workplaces, schools, and other indoor environments, elevated levels of carbon dioxide (CO2) and other pollutants can contribute to ‘sick building syndrome’ [4], characterized by symptoms like headaches, fatigue, and irritability. Improving indoor air quality in these settings can result in higher productivity, improved learning outcomes, and better overall well-being. 

Pairing Indoor Air Quality and Sustainability

Energy-efficient buildings, while beneficial for reducing carbon emissions, can sometimes compromise indoor air quality if they limit natural ventilation to a great extent. As buildings become more airtight to save energy, pollutants can become trapped indoors, leading to a decline in indoor air quality. Striking a balance between energy efficiency and indoor air quality is essential for achieving both environmental sustainability and preserving occupant health.

There are many health risks associated with poor air quality, yet indoor air quality is a preventable contributor to global mortality and illness.

Recognizing the significance of indoor air quality and implementing measures to ensure clean and fresh indoor air is not only a matter of individual well-being but a collective responsibility towards creating healthier and more sustainable indoor environments for generations to come. 

How to improve Indoor Air Quality

Several strategies can be employed to enhance indoor air quality and reap its associated benefits.

Adequate ventilation is crucial, as it helps dilute indoor pollutants and maintains a constant supply of fresh air. Opening windows is an effective measure, but the comfort of doing so varies on the outdoor climate and temperature.

Mechanical ventilation systems, such as air exchange and air purification systems, ensure consistent airflow and pollutant removal.

Proper filtration, regular maintenance of HVAC systems, and the use of low-emission building materials can also contribute to improved indoor air quality.