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Improving Indoor Air Quality: The term “air quality” tends to conjure up the image of smog-filled cities and often makes people think of pollution in populated or industrial regions. Measures such as the Air Quality Index exist to provide information relative to the levels of airborne pollutants in towns and cities and communicate when these levels may cause a risk to, or exacerbate, health issues.1 For instance, when humidity during the summer heightens the risk for asthma sufferers or when hazardous smog amasses in cities, the message is clear: protect your health, stay indoors.2
However, the air we breathe indoors can sometimes be the most polluted air we encounter. Unseen elements and particulate matter inside our homes and offices, from dust to formaldehyde to radon, can lead to health issues in both the short- and long-term.3 Considering that Americans spend about 90% of their time indoors, measuring, controlling, and improving air quality indoors should be a key priority.4
With an ever-expanding body of research connecting COVID-19 cases to low humidity and/or high-levels of air pollution, adequate control and monitoring of these variables in today’s climate is vital.5,6 Throughout, this article examines the factors causing indoor air pollution, the required measures to improve indoor air quality, and, crucially, the possibilities for improving indoor air quality in every home future.
The Causes and Effects of Indoor Air Pollution
Indoor air pollution can originate in and derive from several sources. Fuel-burning appliances and smoking indoors are relatively obvious factors.7 However, other sources are not so apparent, including materials found in furnishing and fittings found in most modern homes. This includes materials such as plywood, adhesives, and insulation, which may contain formaldehyde, benzene, and plenty of other Volatile Organic Compounds (VOCs).8 Many hygiene and cleaning products, such as shampoos and detergents, may include formaldehyde in their elements.
Enclosed spaces can be dangerous when it comes to air pollution, especially if ventilation is inadequate. Hazardous gases and a plethora of airborne pollutants can easily accumulate and linger for long periods of time inside homes and other indoor spaces. Poor ventilation in combination with badly sealed foundations, in particular, can result in a buildup of radon, a dangerous radioactive gas, indoors – the amount can differ dramatically depending on where you live.
The health impact where such substances are concerned can be very real and severe. Early effects of exposure include irritation of the eyes, nose, and throat, together with headaches, fatigue, and dizziness. Combinations of various pollutants can have extra cumulative or synergistic effects, and the long-term effects of exposure to particular common pollutants can be debilitating or even fatal: potentially leading to respiratory diseases, heart disease, and cancer.
How to Improve Air Quality in Your Home
Fortunately, taking certain measures can significantly improve the air quality and safety within the home.
Prevention is better than the cure: the easiest and most effective way to limit the many harmful pollutants present in the home is to eliminate their sources. Restraining from the use of certain materials or products in the home and selecting hypoallergenic (or ‘green’) solutions are powerful ways of improving indoor air quality.
Certain sources can be sealed, such as those containing asbestos, while various fuel-burning appliances can be amended to reduce the number of emissions.9 Yet, it is not always a practical solution to simply remove the sources of pollution, especially when so many everyday household items and materials are known sources of pollutants.
Ventilate Your Home
Increasing ventilation can have drastic effects and can often be the easiest way to mitigate against poor air quality within the home. Opening a window, or a door, or activating a window air conditioner are all effective solutions when it comes to increasing the outdoor air ventilation rate inside your home and avoiding the buildup of hazardous pollutants. Extractor fans, often located in kitchens or bathrooms, that funnel the air outside are also useful when it comes to removing indoor pollution circulating fresh air into the house.
Air Cleaning and Filtration
Air cleaners and filters can be efficient and useful when it comes to eliminating particulate matter from the air indoors. While they’re typically not designed to remove gaseous pollutants, decreasing the number of particulates is key for people suffering from asthma and can also improve pulmonary function.10 When selecting a suitable air filter, take into account that the efficiency and performance of various air filters can greatly vary – when choosing one it is vital to select a model that has both excellent collector efficiency and a high air-circulation rate. Furthermore, changing the filters regularly is an important factor.
The Future of Indoor Air Quality Control
All over the world, there is a significant rise in the use of networkable sensors and controllers to automate the home, these include intelligent thermostats, automated lighting, and keyless locking systems. This growth in home automation, known as the “smart home revolution” provides an opportunity to assume control of indoor air quality.
Advancements in environmental sensing technology make it possible to measure levels of indoor air pollutants such as particulate matter, CO2, and VOCs with increasingly accurate, efficient, compact sensors.11 Therefore, in the future, smart home systems may utilize sensors like these to constantly monitor indoor air quality and trigger ventilation systems before pollutants reach hazardous levels.
Furthermore, such systems have the capacity to monitor humidity levels as well as measuring concentrations of pollutants. The petition 40to60RH refers to the expansion in the body of evidence connecting relative humidity levels outside the ‘optimal’ 40-60% range to increased occurrences of respiratory disease. Therefore, the integration of smart indoor air quality control systems into newly built homes and offices in the near future could have significant benefits for our collective wellbeing.
Indoor air quality is a serious matter where public health is concerned.12 There are transparent guidelines for indoor air quality as set by the World Health Organization and Environmental Protection Agency, and organizations such as ASHRAE are paving the way to ensuring these considerations are integrated into building practices.
Therefore, indoor air quality needs to be taken as seriously as outdoor air quality, with a legislature that details the levels of pollutants acceptable in our homes, offices, and schools. Once environmental regulations are firmly in place, sensing solutions and smart control systems will be key to ensuring clean, safe air for all.
References and Further Reading
- AQI Basics | AirNow.gov. Available at: https://www.airnow.gov/aqi/aqi-basics/. (Accessed: 11th August 2020)
- Hayes, D., Collins, P. B., Khosravi, M., Lin, R.-L. & Lee, L.-Y. Bronchoconstriction Triggered by Breathing Hot Humid Air in Patients with Asthma. Am. J. Respir. Crit. Care Med. 185, 1190–1196 (2012).
- Introduction to Indoor Air Quality | Indoor Air Quality (IAQ) | US EPA. Available at: https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality. (Accessed: 11th August 2020)
- KLEPEIS, N. E. et al. The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. J. Expo. Sci. Environ. Epidemiol. 11, 231–252 (2001).
- ‘Compelling’ evidence air pollution worsens coronavirus – study | World news | The Guardian. Available at: https://www.theguardian.com/world/2020/jul/13/compelling-evidence-air-pollution-worsens-coronavirus-study. (Accessed: 27th August 2020)
- How humidity may affect COVID-19 outcome. Available at: https://www.medicalnewstoday.com/articles/how-humidity-may-affect-covid-19-outcome. (Accessed: 27th August 2020)
- California wants to see how cooking with gas affects indoor air – Health – The Jakarta Post. Available at: https://www.thejakartapost.com/life/2020/05/09/california-wants-to-see-how-cooking-with-gas-affects-indoor-air.html. (Accessed: 11th August 2020)
- World Health Organization Guidelines for Indoor Air Quality. (2010).
- Improving Indoor Air Quality | Indoor Air Quality (IAQ) | US EPA. Available at: https://www.epa.gov/indoor-air-quality-iaq/improving-indoor-air-quality. (Accessed: 11th August 2020)
- Anderson, H. R., Favarato, G. & Atkinson, R. W. Long-term exposure to air pollution and the incidence of asthma: meta-analysis of cohort studies. Air Qual. Atmos. Heal. 6, 47–56 (2013).
- Environmental Sensors | Sensirion. Available at: https://www.sensirion.com/en/environmental-sensors/. (Accessed: 11th August 2020)
- Dales, R., Liu, L., Wheeler, A. J. & Gilbert, N. L. Public health: Quality of indoor residential air and health. CMAJ 179, 147–152 (2008).