Doctoral Research by Liz McCormick, AIA, LEED AP, CPHC
North Carolina State University
Americans spend upwards of 90% of their lives indoors and one-third of their time at work (US EPA). However, the quality of indoor air can actually be two to five times worse than outdoor environments, especially in regard to airborne chemicals, though most Americans still perceive the risks of outdoor air pollution as being substantially higher than indoor air. Even though threats posed by long-term exposure to unhealthy indoor air have become more apparent in recent years, the architectural response is limited, particularly when constrained by urban contexts. The intent of this research is to dispel the notion that healthy, high-performance buildings must implement sealed enclosures that separate the occupant from the outdoors. Instead, we believe that truly healthy architecture will blur the edge between inside and out.
This research project will monitor built and occupied urban office buildings across the US Southeast that utilize both indoor and outdoor space as part of the workplace strategy. By understanding occupant behavior in the context of the quantitative metrics of indoor air quality, we hope to combine the healthful benefits of the outdoors with the functionality of indoor workplaces.
When one thinks about air pollution, they may picture dark, billowing clouds of smoke or murky urban sunsets. However, given the amount of time we spend indoors, it is actually substandard indoor air that is causing the greatest impact on human health in the United States. Allergies, for example, have increased dramatically across the developed world due to chemical exposures in low-quality indoor air (Rios et al. 2009; Sundell 2004).
The Clean Air Act is the federal law that regulates air pollution outdoors and has dramatically improved ambient pollution levels across the country. Initially enacted in 1963 and amended many times since, it sets safe standards for ground-level ozone, particle pollution (particulate matter), carbon monoxide, sulfur dioxide and nitrogen dioxide. However indoor air remains largely unregulated, despite growing evidence of potentially harmful impacts. The pollutants most studied indoors include: ozone (O3), carbon monoxide (CO), particulate matter (PM2.5 and PM10), volatile organic compounds (VOC or TVOC), and formaldehyde (HCHO). Additionally, carbon dioxide (CO2) can be a good indicator of the general freshness of the air, though it is not particularly harmful in itself. Other common concerns are respiratory disease, radon, chemical buildup, second hand smoke, legionella bacteria as well as more benign contaminants including mold, dust, pet dander, and insect allergens.
Current international guidelines, including from the American Society of Heating and Refrigerating Engineers (ASHRAE), require a minimum of 15 cubic feet per minute (CFM) per person of fresh air ventilation. However, recent studies, including the Cognitive Function (COGfx) study call for ‘enhanced’ ventilation of at least 40 CFM per person to maintain minimum standards of indoor environmental health. The team found that cognitive function scores of the studied professional-grade employees were 61% higher in the simulated green building (20 CFM/person, low VOC) and 101% higher in the Green+ building (40 CFM/person, low TVOC), low VOC), compared with the base (conventional) condition (20 CFM/person, high VOC) (Allen et al. 2016). Follow-up studies found that providing enhanced ventilation at a rate of 40 CFM/person would cost less than $40/person/year but improve employee performance by 8%, or $6,500/year (MacNaughton et al. 2015).
Allen, Joseph G., Piers MacNaughton, Usha Satish, Suresh Santanam, Jose Vallarino, and John D. Spengler. 2016. “Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments.” Environmental Health Perspectives 124 (6): 805–12. https://doi.org/10.1289/ehp.1510037.
MacNaughton, Piers, James Pegues, Usha Satish, Suresh Santanam, John Spengler, and Joseph Allen. 2015. “Economic, Environmental and Health Implications of Enhanced Ventilation in Office Buildings.” International Journal of Environmental Research and Public Health 12 (11): 14709–22. https://doi.org/10.3390/ijerph121114709.
Rios, José Luiz de Magalhães, José Laerte Boechat, Adriana Gioda, Celeste Yara dos Santos, Francisco Radler de Aquino Neto, and José Roberto Lapa e Silva. 2009. “Symptoms Prevalence among Office Workers of a Sealed versus a Non-Sealed Building: Associations to Indoor Air Quality.” Environment International 35 (8): 1136–41. https://doi.org/10.1016/j.envint.2009.07.005.
Sundell, J. 2004. “On the History of Indoor Air Quality and Health.” Indoor Air 14 (s7): 51–58. https://doi.org/10.1111/j.1600-0668.2004.00273.x.
This project requires significant equipment and travel costs. Contributions made to NCSU Research Fund to support this work will be tax-deductible. No goods or services will be provided in exchange for your donation to support this research. All gifts to NCSU are considered tax-deductible to the extent allowed by law.
Liz McCormick is a doctoral candidate at NCSU as well as an Assistant Professor of Architecture and Building Technology at the University of North Carolina at Charlotte. She is a licensed architect, LEED AP, and CPHC.
Dr. Traci Rider, PhD is an Assistant Professor at NCSU and is supervising McCormick’s PhD research. Rider’s research focuses on health in the built environment, specifically in how design can support public health outcomes. She is the author of several books, including her most recent publication, Building for Well-Being.
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