Indoor climate and well-being
Health and safety

Indoor Air Quality for Health and Well-being

1 January 1

With most of our time — around 20 hours per day — spent indoors, building air quality has a significant impact on our well-being.

indoor-quality-for-wellbeing

Pandemic Shines Spotlight on Indoor Air Quality 

The argument and controversy surrounding air quality have never been more spoken, and the pandemic has pushed building ventilation and air cleaning into the spotlight. People want to know that buildings are well-ventilated and that the air is free from toxins and viruses. We are more aware than ever of the air we breathe and the health consequences of polluted air. This includes both indoor and outdoor air.  

Furthermore, the advent of COVID-19 resulted in a shift in working patterns for many employees, who now work from home remotely. However, when compared to traditional office settings with better air conditioning and ventilation systems, residences may not be an ideal working environment. Furthermore, activities carried out by individuals at home may contribute to increased indoor air pollution, hence contributing to additional unfavourable health consequences. 

The study found that the air quality in homes was worse than in the workplace before the pandemic for all participants. People also experienced a higher frequency of sick building syndrome (SBS) symptoms while working from home. Home Indoor Air Quality (IAQ) was specifically worse than outdoor air quality, and PM2.5 levels in all households while working from home exceeded the health-based threshold of 12 µg/m3 [1]. 

Do you know that: when at rest, the normal human inhales, and exhales around 13kg of air every day? This contrasts with the approximately 2kg of food and 3kg of fluids we consume. The amount of health advice on breathing is much less than the amount of information on what we should eat and drink. 

In this article, we highlight some of the key factors affecting indoor air quality, and what you can do to improve it.  

Close the Door on Air Pollution? Don’t Think So…   

We might think that by closing our doors and windows we leave all the adverse effects of pollution out of our house, but the reality is quite different. Indoor air quality can often be worse than outdoors. 

Indoor Air Quality

Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, particularly as it relates to building occupants' health and comfort. Understanding and eliminating common indoor contaminants can help you lower your risk of indoor health issues.

Bar chart number of cities for mean concentration of PM

Importance of Indoor Air Quality 

The potential impact of indoor air quality on human health on an international scale is notable for several reasons: 

  • We spend most of our time inside, where the concentrations of some pollutants are often 2 to 5 times greater than usual outdoor amounts [2]
  • Persons who are more vulnerable to the negative effects of pollution (e.g., the noticeably young, older adults, people with cardiovascular or respiratory problems) tend to spend even more time indoors. 
  • In recent decades, the use of energy-efficient building construction techniques and synthetic materials in homes has led to an increase in indoor concentrations of some pollutants. These pollutants can cause health problems if they are present at prominent levels. 

How Does Outdoor Air Pollution Enter a Building? 

There are three ways for outdoor air to enter and exit a building: infiltration, natural ventilation, and mechanical ventilation.  

What If You Live in an Apartment? 

Because many of the pollution sources, such as interior building materials, furnishings, and household goods, are comparable, apartments can have the same indoor air concerns as single-family homes. Indoor air quality issues, like those seen in workplaces, are produced by causes such as contaminated ventilation systems, incorrectly located outdoor air intakes, or maintenance activities.  

Know your Enemies and Know yourself 

As Sun Tzu wrote in the book “Art of war,” ‘if you know your enemy and you know yourself you shall win a hundred battles without loss.’ In other words, we need to understand the root causes to solve the problem. 

Table 1: Common indoor pollutants and their effects on human health[3] 

Pollutants 

Sources 

Health Risks 

PM 

Outdoor environment, cooking, combustion activities (burning of candles, use of fireplaces, heaters, stoves, fireplaces and chimneys, cigarette smoking), cleaning activities 

Premature death in people with heart or lung disease, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function, increased respiratory symptoms.

 

VOCs 

Paints, stains, varnishes, solvents, pesticides, adhesives, wood preservatives, waxes, polishes, cleansers, lubricants, sealants, dyes, air fresheners, fuels, plastics, copy machines, printers, tobacco products, perfumes, dry-cleaned clothing, building materials and furnishings 

Eye, nose, and throat irritation. 

Headaches, loss of coordination and nausea. 

Damage to liver, kidney, and central nervous system.

Some organics can cause cancer. 

 

NO2 

Gas-fuelled cooking and heating appliances 

Enhanced asthmatic reactions. 

Respiratory damage leading to respiratory symptoms. 

 

O3 

Outdoor sources, photocopying, air purifying, disinfecting devices 

DNA damage, lung damage, asthma, decreased respiratory functions. 

 

SO2 

Cooking stoves; fireplaces; outdoor air 

Impairment of respiratory function. 

Asthma, chronic obstructive pulmonary disease (COPD), and cardiovascular diseases.

 

COx 

Cooking stoves; tobacco smoking; fireplaces; generators and other gasoline powered equipment; outdoor air 

Fatigue, chest pain, impaired vision, reduced brain function.

 

Heavy metals 

Pb, Cd, Zn, Cu, Cr, As, Ni, Hg, Mn, Fe 

Outdoor sources, fuel-consumption products, incense burning, smoking and building materials 

Cancers, brain damage. 

Mutagenic and carcinogenic effects: respiratory illnesses, cardiovascular deaths.

 

Aerosols 

Tobacco smoke, building materials, consumer products, incense burning, cleaning and cooking 

Cardiovascular diseases, respiratory diseases, allergies, lung cancer, irritation and discomfort.

 

Radon (Rn) 

Soil gas, building materials, and tap water 

Outdoor air 

Lung cancer.

 

Pesticides 

Termiticides, insecticides, rodenticides, fungicides, disinfectants, and herbicides 

Building materials: carpet, textiles, and cushioned furniture 

Outdoor environment 

Irritation to eye, nose and throat; 

Damage to central nervous system and kidney; 

Increased risk of cancer.

 

Biological allergens 

House dust, pets, cockroaches, mould/dampness, pollens originating from animals, insects, mites, and plants 

Asthma and allergies 

Respiratory infections, sensitization, respiratory allergic diseases and wheezing.

Microorganism 

Bacteria, viruses, and fungi are carried by people, animals, and soil and plants 

Fever, digestive problems, infectious diseases, chronic respiratory illness.

 

Other Factors Affecting Indoor Air Quality 

In addition, the air exchange rate, external climate, weather conditions, and tenant behaviour all have an impact on indoor air quality. 

As discussed earlier, the speed of air exchange with the outside environment is a key component in determining indoor air pollution concentrations. The air exchange rate of a building is influenced by its design, construction, and operating parameters, and it is a function of infiltration, natural ventilation, and mechanical ventilation. 

Outdoor climate and weather conditions, as well as a human activity, can all have an impact on indoor air quality. Weather influences whether building occupants keep windows open or closed, as well as whether they use air conditioners, humidifiers, or heaters, all of which can have an impact on indoor air quality.  

Certain climatic conditions, if not controlled by sufficient ventilation or air conditioning, might enhance the possibility of indoor moisture and mould formation. 

Still not convinced? 

The health effects of poor indoor air quality can vary from low levels of concentration and fatigue to premature death. According to the Global Burden of Disease, 4.1% of global deaths are attributed to indoor air pollution[4].

It can influence our cognitive functioning and lead to reduced productivity. The impact of VOCs (Volatile Organic Compounds) can lead to air and throat irritation, nausea, and headaches.  

 

Definitions

  • Infiltration refers to the process of air that flows into structures through openings, joints, and cracks in walls, floors, and ceilings, as well as around windows and doors.
  • Natural ventilation means air that flows through opened windows and doors.
  • Mechanical ventilation refers to air that is forced indoors or vented outdoors by ventilation devices, such as fans or air handling systems.
Bar chart number of death reasons

Studies have shown that cognitive scores can be 101% higher in buildings that have invested in good indoor air quality and enhanced ventilation[5].

The investment will not only lead to healthier and happier people but can have a direct economic impact. Highly engaged employees can lead to improved business performance by up to 30% and 3 out of 4 building owners report that healthy buildings can be more easily leased. 

Improving the Air Quality Indoor 

Source Control 

Typically, the most effective strategy to enhance indoor air quality is to eliminate or reduce sources of pollution. Some sources, such as those containing asbestos, can be sealed or enclosed; others, such as gas stoves, can be adjusted to reduce emissions.

In many circumstances, source management is also a more cost-effective method of safeguarding indoor air quality than boosting ventilation, because increasing ventilation can raise energy expenses.  

Ventilation Improvements 

Another method for reducing the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air that enters your home. Most home heating and cooling systems, including forced air heating systems, do not bring in fresh air manually.  

When the weather permits, opening windows and doors, running window or attic fans, or running a window air conditioner with the vent control open all improve the rate of outside ventilation. Local bathroom or kitchen fans that exhaust outside eliminate impurities from the room where the fan is positioned while simultaneously increasing the pace of external air circulation. 

Follow Indoor Air Quality Guidelines 

Table 2: Indoor air quality guidelines for major indoor air pollutants [3] 

Pollutants 

Concentration Levels (mg/m3) 

Exposure Time 

Organization 

CO 

100 

15 min 

WHO 

60 

30 min 

30 

1 h 

10 

8 h 

CO2 

1800 

1 h 

WHO 

NO2 

0.4 

1 h 

WHO 

0.15 

24 h 

PM 

0.15 

24 h 

USEPA 

0.05 

1 year 

O3 

0.15–0.2 

1 h 

WHO 

0.1–0.12 

8 h 

SO2 

0.5 

10 min 

WHO 

0.35 

1 h 

Pb 

0.0005–0.001 

1 year 

WHO 

Xylene 

8 

24 h 

WHO 

Formaldehyde 

0.1 

30 min 

WHO 

Radon 

100 Bq/m3 

1 year 

WHO 

Building Materials Selection 

Improving air purification and selecting materials that are naturally mould and mildew resistant can lead to significant improvements in indoor air quality.

A focus on good building fabric that provides effective insulation and good air filtration can also help. 

VOC emissions from construction products are regulated in many parts of the world such as California and Europe. However, there are more products that go one step further, imposing stricter limits to indoor air emissions, and encouraging an even better indoor air environment. These are reflected in the labels supplied in support of sustainability certification of a building such as LEED, BREEAM, WELL, HQE and DGNB. They are also an important indicator of the sustainability assessment of the building.   

The WELL certification system, which comprises 29 air quality metrics and requirements, focuses on variables that affect human health and well-being rather than solely environmental assessment. 

Over 2000 building projects in 52 countries have employed the WELL certification, demonstrating the influence that good building design and indoor air quality can have on employee health, well-being, and productivity. 

Rockfon products hold the best-in-class indoor climate labels so you can be sure of the level of indoor air quality when selecting a Rockfon product.  

Our products, depending on the market and type, can have the following labels:   

  1. French VOC A+   
  2. Cradle to Cradle Silver/Bronze   
  3. Finnish M1   
  4. Blue Angel   
  5. Danish Indoor Climate Label   
  6. Singapore Green Building Product Certificate   

Making sure that you select products that hold such labels is essential to achieve a good environment for the building occupants and a real investment for the future.

Sources: 

  1. Roh, Taehyun, Alejandro Moreno-Rangel, Juha Baek, Alexander Obeng, Nishat Tasnim Hasan, and Genny Carrillo. 2021. “Indoor Air Quality and Health Outcomes in Employees Working from Home during the COVID-19 Pandemic: A Pilot Study.” Atmosphere 12 (12): 1665. https://doi.org/10.3390/atmos12121665. 
  2. US EPA,ORD. 2018. “Indoor Air Quality | US EPA.” US EPA. July 16, 2018. https://www.epa.gov/report-environment/indoor-air-quality. 
  3. Tran, Vinh Van, Duckshin Park, and Young-Chul Lee. 2020. “Indoor Air Pollution, Related Human Diseases, and Recent Trends in the Control and Improvement of Indoor Air Quality.” International Journal of Environmental Research and Public Health 17 (8): 2927. https://doi.org/10.3390/ijerph17082927. 
  4. Roser, Max, and Hannah Ritchie. 2014. “Indoor Air Pollution.” Our World in Data. 2014. https://ourworldindata.org/indoor-air-pollution 
  5. “Good IAQ Improves Workers’ Response.” 2015. Cooling Post. November 4, 2015. https://www.coolingpost.com/features/good-iaq-improves-workers-response/.