By.  Richard L. Corsi, Ph.D., P.E., Chair and ECH Bantel Professor for Professional Practice, Department of Civil, Architectural, and Environmental Engineering, The University of Texas at Austin

My colleagues, students, and I were selected as one of seven university teams to complete a multi-year study of indoor air quality in U.S. schools as part of the United States Environmental Protection Agency’s (EPA) initiative Healthy Schools: Environmental Factors, Children’s Health and Performance, and Sustainable Building Practices. As the name of our study indicates, we are focusing on indoor air quality in high schools, and we have developed partnerships with forward-thinking school districts in Texas that not only want to make their high schools healthier, but also want to use the opportunity to help educate and inspire their students on this important topic that addresses all aspects of STEM (Science, Technology, Engineering, and Mathematics).  More information about our study is provided below, but first I wish to underscore the importance of indoor air quality in schools and the need for continued research on this topic.

Schools have a unique place in the fabric of America. Primary and secondary education is the largest public enterprise in the U.S., and educational service is our second largest industry.[1][2]  More than 55 million children attend over 130,000 K-12 schools in the U.S.[3]  Combined with three million teachers and staff, nearly one in five Americans spends time in school buildings each school day.  Children spend 1.6 total years inside school buildings by the time they graduate from high school.[4]   Given these facts, one might conclude that we have done all we can to make school environments as healthy as possible for our children and teachers.  Have we?

There is growing evidence that poor indoor air quality leads to increases in student illnesses and absenteeism, and decreases in academic performance.[5][6][7][8] Teachers are also affected, with higher rates of work-related upper-respiratory problems compared to the rest of the working population.[9]  Combined, these effects come with considerable costs related to children’s health, inferior learning conditions, absenteeism, reduced funding to school districts, crisis remediation of school facilities, and negative stigmatization of affected schools.  Research is needed to identify common indoor air quality problems faced by our nation’s schools and to derive low-cost solutions for those problems to make schools healthier environments.

Numerous research teams have studied indoor air quality in schools.  Our team at the University of Texas at Austin has identified nearly 600 peer-reviewed journal papers on this subject in the past decade alone.  However, these studies have been deficient in many ways.  For one, they have been dominated by K-8 classrooms.  Our team has identified only four papers involving indoor air quality measurements in only three high schools in North America. Biological sampling in schools has been dominated by culture-based methods, which detect only a small fraction of the biological agents actually present in air and dust.  Measurements of volatile organic compounds (VOCs) in schools have focused on species that are acutely toxic at high concentrations or chronically toxic at low concentrations, and not on less toxic oxygenated VOCs (OVOCs) that may be more relevant to short-term respiratory, eye, nose, or neurological effects that influence learning experiences for children. A large majority of past studies have been completed in temperate climates in the United States and Europe; schools in hot and humid climates consistent with the rapidly growing southeastern United States have been woefully under-represented.  Finally, past research has focused on identifying problems and not low-cost solutions that would reduce the potentially harmful effects of indoor air quality in schools.  Our team is addressing each of these issues and more over a four-year period.

The goal of our study is to address these research gaps by conducting an intensive field campaign to delineate the relationship between environmental factors and student and teacher health and perceptions, and then to investigate the efficacy of low-cost solutions to help schools become healthier.  We are (1) identifying systematic problems with school HVAC systems that cause poor ventilation rates, increased pollutant concentrations, and  adverse health symptoms for school occupants;   (2) utilizing molecular techniques to investigate relationships between composition and diversity of the microbial community present in high school classrooms, environmental conditions, and health symptoms; (3) delineating the sources of and role of OVOCs on student and teacher health outcomes; (4) developing and testing low-cost solutions for improving the indoor air quality of high schools; and (5) engaging high school student and teacher “stewards” in the design, data collection, and outreach components of the study.

During our field campaign we do intensive walk-throughs of every high school, which informs our school-specific field sampling plans.  At each high school, we are collecting large numbers of indoor air and environmental samples in four to five locations each semester.  In addition to indoor samples, we collect samples from HVAC systems (filter cakes), and outdoors (rooftops) for specific air quality parameters. Sampling at each location is completed for four consecutive days and includes measurements of comfort parameters such as temperature and relative humidity, carbon dioxide, air exchange rates, HVAC cycling, noise, illuminance, size-fractionated particulate matter, bioaerosols, surface microbes, microbes on HVAC filter cakes, formaldehyde, terpenes and terpene alcohols (largely from scenting agents), other VOCs (e.g., OVOCs), and ozone.  To the extent possible, we are also identifying other important metadata, including major sources of indoor and outdoor pollutants at each school, the nature of cleaning products and practices, number of health-related absences before, during, and after cold and flu season, and more.  Teachers and students are also providing anonymous and voluntary health and perception data via surveys.

Our team will be spending summer months analyzing mountains of data and testing several key hypotheses.  But we are also working with our school partners to access unoccupied classrooms and other school spaces to evaluate low-cost solutions to improve indoor air quality.  Examples include removal of specific sources, low-cost measures for improved pressure balancing to reduce pollutant entry through interstitial spaces, and testing and economic analyses of improved filter technologies.

A central objective of our effort is to excite 9th and 10th grade students about STEM fields, in our case building science.  As such, our collective high school partners have identified over 60 bright young participants who serve as our student “stewards,” as well as their teacher stewards.  Our team has completed can u buy ambien online detailed and hands-on workshops with every school to introduce student stewards and teacher stewards to the field of indoor air quality.  As but one exercise, student stewards are challenged to collect surface swab samples, which are then analyzed by our team before returning to schools to explain how microbes in their samples vary across locations in their own high schools.  The student stewards also shadow our team when we set up our test equipment, and are included in meetings and debriefings to schools on our research findings.  This summer we will have several week-long indoor air quality boot camps at the University of Texas at Austin, during which high school student teams will do experiments on a different indoor air quality topic each day.

While our team has only been in the field for one semester and our findings are preliminary, some interesting trends are emerging.  A few examples are summarized below:


Students are important sources of some indoor air pollution. Student entry into classrooms generally leads to elevated particulate matter associated with resuspension of dust and shedding from clothing and skin.  Furthermore, a major source of terpenes and terpene alcohols in classrooms are popular body sprays.  Through product analyses in our laboratory we have even identified the fingerprint of the specific body spray that appears to be the most popular with students in our high schools.


 “No fragrance” policies can be effective. One high school in our study has a rigorous “no fragrance” campaign and policy out of concern for students and teachers who have allergic responses to chemicals used in fragrances.  Their efforts seem to be highly effective, as we find very low concentrations of chemicals used as scenting agents in that high school.


Floor finishes and whiteboard cleaners are important sources of OVOCs. We have determined that the major sources of OVOCs in our partner schools are associated with a floor finish that is popular across school districts, as well as products used to clean white boards.


Energy conservation measures can lead to elevated carbon dioxide (CO2) levels.  There are significant differences in the degree of outdoor air ventilation of classrooms between high schools, and even between different wings in the same high school.  The majority of classrooms exceed accepted standards for CO2. Occupied-day CO2 concentrations are significantly higher in schools with the most robust energy conservation policies.  This might lead to significant differences in cold- and flu-related absences between schools or even for students who spend differing amounts of time in different wings of the same school during winter months, associations that we will evaluate as our study proceeds.


Indoor ozone levels are generally inversely related to carbon dioxide. Indoor ozone concentration profiles track outdoor concentrations over the course of a day but, as expected, are much lower.  The indoor-to-outdoor ratio of ozone concentration is, in general, inversely related to CO2 concentrations.  This reflects either more time for ozone removal by reactions in classrooms (i.e., at lower air exchange rates), greater surface area of skin and clothing for ozone to react with in densely occupied classrooms, or both.  Our team will explore low-cost methods for lowering ozone concentrations in both well- and poorly-ventilated classrooms.


Formaldehyde is the primary concern regarding building materials. Formaldehyde concentrations in our partner high schools are rarely above the acute but never below the 8-hour California OEHHA (Office of Environmental Health Hazard Assessment) Exposure Reference Levels.  They are highly variable, even during the same day, and depend primarily on variations in classroom ventilation. This latter finding indicates the need for consideration of both acute and time-integrated analysis in future studies of formaldehyde in schools.


I emphasize that these are just several examples of preliminary results from our study.


It is satisfying to do research that may one day lead to improvements in environments so important to the health and education of our nation’s children, and exciting to introduce a wonderful cohort of high school students to the topic of indoor air quality. The EPA deserves significant kudos for taking the lead on this very important initiative, and for funding a network of university teams that are addressing and advancing knowledge on how to improve the health of our nation’s schools.


About Richard Corsi:

Richard CorsiDr. Richard L. Corsi is the Chair of the Department of Civil, Architectural, and Environmental Engineering, ECH Bantel Professor for Professional Practice, and the William David Blunk Memorial Professor at the University of Texas at Austin (UT).  His research focuses on interactions of pollutants with indoor materials and innovative strategies for improving indoor air quality.  He is past President of the major international conference Indoor Air 2011 and a member of the International Society of Indoor Air Quality and Climate Academy of Fellows.  Dr. Corsi has been honored as a Distinguished Alumnus of Humboldt State University and Distinguished Alumnus of the College of Engineering at the University of California, Davis.  He teaches undergraduate and graduate courses related to indoor air quality, and has received numerous teaching awards, including induction into the prestigious UT Academy of Distinguished Teachers.



[1] Godwin, C., and Batterman, S., “Indoor Air Quality in Michigan Schools,” Indoor Air, 17: 109-121 (2007)

[2] Tak, S., et al. “Excess Risk of Head and Chest Colds among Teachers and Other School Workers,” Journal of School Health, 81(9): 560-565 (2011).

[3] United States Department of Education, Digest of Education Statistics, National Center for Education Statistics (NCES 2009-020), (2009).

[4] Juster, F.T., Ono, H., and Stafford, F.P., “Changing Times of American Youth: 1981-2003,” Institute for Social Research, University of Michigan (2004).

[5] Jones, S.E., Smith, A.M., Wheeler, L.S., and McManus, T., “School Policies and Practices that Improve Indoor Air Quality,” Journal of School Health, 80(6): 280-286 (2010).

[6] Almeida, S.M., et al., “Children Exposure to Atmospheric Particles in Indoor of Lisbon Primary Schools,” Atmospheric Environment, 45: 7594-7599 (2011).

[7] Jones, S.E., Axelrad, R., and Wattigney, W.A., “Healthy and Safe School Environment, Part II, Physical School Environment: Results from the School Health Policies and Programs Study 2006,” Journal of School Health, 77(8): 544-556 (2007).

[8] Lin, S., et al., “Comparison of Indoor Air Quality Management Strategies between the School and District Levels in New York State,” Journal of School Health, 82(3): 139 146 (2012).

[9] Tak, S., et al. “Excess Risk of Head and Chest Colds among Teachers and Other School Workers,” Journal of School Health, 81(9): 560-565 (2011).