Significance and Importance of the Indoor Environment

Indoor air is important because it is directly related to human health.

“The United States Environmental Protection Agency (EPA) and its Science Advisory Board (SAB) have ranked indoor air pollution among the top environmental risks to public health” (U.S. EPA, 1987a; U.S. EPA-SAB, 1990).

Because air is invisible and particles are impossible to detect with the human eye, the threat of poor air is often undermined. Energy savings can be calculated in kilowatts and dollars, but it is difficult to estimate healthcare costs and even more challenging to assign a monetary value to quality of life.

Architecture is both protecting and hurting us at the same time. The risk of poor indoor air is high because the amount of time we spend indoors. Humans have gradually transitioned from being an outdoor species to an indoor species. The National Human Activity Pattern Survey (NHAPS) shows where humans spend their time. The data from this study was collected between 1992–1994 and the study was sponsored by the EPA. According to the NHAPS, participants spent about 87% of their time indoors (Klepeis et al, 2001, pg. 15). We may spend even more time indoors now than we did in the early 1990s.

According to the NHAPS, more time is spent in a residence than any other place. Because of the amount of time humans spend in a residence, this thesis will focus on residential architecture in the United States. The home is an important space because in addition to being a place of protection and respite,

“more than half the body’s intake during a lifetime is air inhaled in the home. Thus, most illnesses related to environmental exposures stem from indoor air exposure” (Sundell, 2004, pg. 51).

Some of the challenges of this thesis deal with the lack of research on residential architecture. “Studies on the association between health effects and ventilation rates in homes are rare” (Sundell, 2004, pg. 55). While they exist in commercial environments, the home is not studied as frequently. It is also difficult to establish either correlation or causation because it is unethical to test a potentially harmful substance on humans.

Dr. Jeffrey Siegel wrote an article called Engineering the Indoor Environment. Siegel states,

“The average person breathes, by comparison, approximately ten times more indoor air than they consume in water (in both food and drink)” (Siegel, 2011, pg. 349).

If we care about standards for food and water, then we should certainly pay attention to indoor air. Outdoor air, food, and water are heavily regulated, but there are no national regulations for indoor air. Outdoor air does play a role in indoor air because the air that enters the indoor comes from the outdoors. The significance of this thesis is underscored by the fact that we spend a majority of our lives indoors and this environment is the only place of exposure for some of these toxins. Unhealthy indoor environments affect all people, but not equally. People who live in low-income areas are more likely to experience poor indoor air quality.

“Indoor concentrations of multiple pollutants are elevated in low-socioeconomic status households” (Adamkeiwicz, 2011, pg. S238).

Children, elderly, and people who have sickness or compromised immune systems are more likely to spend time indoors and can be impacted by the indoor environment more than a healthy middle-aged person. Because there is little to no regulation for the indoor environment, it is a designer’s responsibility to choose materials that promote indoor environmental quality.

Bibliography

Adamkiewicz, G., Zota, A. R., Fabian, M. P., Chahine, T., Julien, R., Spengler, J. D., & Levy, J. I. (2011). Moving Environmental Justice Indoors: Understanding Structural Influences on Residential Exposure Patterns in Low-Income Communities. American Journal of Public Health, 101(S1), S238–S245. https://doi.org/10.2105/AJPH.2011.300119

Klepeis, N., Nelson, W., Ott, W., Robinson, J., Tsang, A., Switzer, P., … Englemann, W.H. (2001). The National Human Activity Pattern Survey (NHAPS): A resource for assessing exposure to environmental pollutants. Journal of Exposure Science & Environmental Epidemiology, 11(3), 231–252. https://doi.org/10.1038/sj.jea.7500165

United States Environmental Protection Agency. (1987a). Unfinished Business: A Comparative Assessment of Environmental Problems. Retrieved from https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=2001635G.TXT

United States Environmental Protection Agency. (1990). U.S. EPA Science Advisory Board (SAB). 1990. “Reducing Risk: Setting Priorities and Strategies for Environmental Protection https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=2000PNG1.TXT.

Siegal, J. (2011). Engineering the Indoor Environment. In L. Weinthal (Ed.), Toward a New Interior: An Anthology of Interior Design Theory. New York: Princeton Architectural Press.

Sundell, J. (2004). On the history of indoor air quality and health. International Center for Indoor Environment and Energy, Technical University of Denmark, Lyngby, Denmark, 14(s7), 51–58. https://doi.org/10.1111/j.1600-0668.2004.00273.x