Deficient Indoor Air Quality: A Serious Threat to all Campus Buildings, Especially Hospitals and Schools

Cleaner and healthier indoor air achieved via energy recovery ventilation improves the health, cognitive function, productivity and wellbeing of all building occupants

By Nick Agopian
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Deficient IAQ threatens all campus buildings, especially hospitals and schools. Image courtesy of Cleaning Management Institute

Buildings in campus settings, in particular hospitals and K-12 schools, are extremely vulnerable to deficient indoor air quality (IAQ). This is especially true with improved air-sealing methodologies on the rise that not only trap in air but also numerous internally generated contaminants from structures and occupants via off-gassing and activities. Deficient IAQ has many adverse effects on the occupants of these campus buildings, such as increased infection rates in hospitals and impaired academic performance for students in schools, to name just a few.

The best way to enhance IAQ is with increased ventilation, but conventional systems waste energy and therefore lead to additional costs. So how can IAQ be enhanced energy-efficiently, cost-effectively and sustainably in order to support both the physical and mental health of hospital and school occupants? The answer is through balanced energy recovery ventilation, a process that reuses otherwise-wasted heat and humidity from the exhaust air going out to precondition the outdoor air coming in, resulting in cleaner and healthier indoor air and HVAC energy costs reduced by up to 40 percent.

The Situation: Deficient IAQ Threatens all Buildings—Especially Hospitals & Schools
With buildings becoming increasingly air-sealed, a consequence is a rise in deficient IAQ, which is a serious—yet often unnoticed—threat to occupant health, cognitive function, productivity and general wellbeing. Deficient IAQ is especially concerning since people are indoors about 90 percent of the time (the elderly 95 percent) and the Environmental Protection Agency (EPA) found that indoor air may be two to five times, and occasionally greater than 100 times, more polluted than outdoor air. Hence the EPA ranks indoor air pollution among the top-five environmental risks to public health.1

If that’s not enough to instill concern over deficient IAQ, the World Health Organization (WHO) determined that in 2012, 4.3 million deaths globally were attributable to indoor air pollution.2 The WHO also found that 30 percent of all new or renovated buildings suffer from deficient IAQ, that 24 percent of U.S. workers perceived indoor air quality problems and that 20 percent of these workers believed their performance was hampered as a result.3 Further, the average person uses 33 pounds of air a day compared to only about two pounds of food and about four pounds of water, thus underlining the importance of high-quality indoor air.4

What causes deficient IAQ? A complex array of internally generated contaminants, such as toxins, vapors, gases, chemicals, odors and other Volatile Organic Compounds (VOCs), can build up and diminish IAQ in hospitals, schools and all homes and buildings. Contaminants are introduced in many ways, but the primary means is by being off-gassed from sources such as construction materials, furniture, fabrics, carpets, paints, sealants, finishes, cleaning supplies, human activity and even the human metabolic process that emits bioeffluents.

Hospitals and schools are at particular risk of experiencing deficient IAQ due to their high-occupant densities, constant maintenance needs and budget constraints. Regarding hospitals, there are so many indoor air contaminants being introduced constantly that the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) stated in its HVAC Design Manual for Hospitals and Clinics that, “Healthcare facilities are environments of controlled hazards.”5

Schools also suffer considerably from deficient IAQ. The EPA determined that schools can have up to four times the number of occupants as an office building of similar size, meaning that more carbon dioxide (CO2)—which is considered an indoor air contaminant—is exhaled into the air.6 What’s more, the EPA listed deficient IAQ as a serious problem faced by the U.S.’s schools since it found that about 50 percent of school buildings have problems linked to poor indoor air quality.7

Specifically for hospitals and schools, the primary indoor air contaminants found inside each building type are listed below:

Indoor Air Contaminants in Hospitals & Schools8

Contaminants

Sources

Adverse Effects

Humidity

Exhaled breath, water sources (faucets, showers, leaks)

Aggravated allergies and asthma

Carbon dioxide

Exhaled breath

Headaches, fatigue, drowsiness, eye and throat irritations, cognitive impairment, decision-making difficulty

Formaldehyde

Off-gassed from adhesives, fabric treatments, stains, varnishes

Irritations to respiratory system, eyes, nose and throat, known carcinogen potentially causing cancer

Other Volatile Organic Compounds (VOCs), toxic gases, vapors

Off-gassed from furniture, carpets, paints, cleaners, solvents, glues, other building materials

Headaches, fatigue; irritations to eyes, nose, throat and skin

Odors

Bathrooms, kitchens, pets, occupants

Headaches, dizziness, nausea

Bioeffluents

Human metabolic process

Headaches, fatigue, drowsiness; irritations to eyes, nose, throat and skin

Molds, microbial contaminants, fungi

Stagnant water, drains, condensate pans, damp areas

Aggravated allergies and asthma

Bacteria, viruses

Skin microbiota, coughing

Sicknesses, diseases, infections (such as Methicillin-resistant Staphylococcus aureus or MRSA)

Radon

Uranium decaying in the soil

Cell damage, carcinogen potentially causing cancer

Dust mites

Carpets, fabric, foam cushions

Aggravated allergies and asthma

Phthalates

Off-gassed from adhesives, vinyl flooring, wood finishes, plastic plumbing pipes, other building materials

Obesity, reproductive problems, carcinogen potentially causing cancer

Carbon monoxide

Gas heating systems, gas stoves, gas hot-water heaters, cigarette smoke, cars inside parking garages

Headaches, fatigue, dizziness

Tobacco smoke

People smoking inside or near a home or building (first-hand, second-hand, third-hand)

Headaches, dizziness, carcinogen potentially causing cancer

Ozone

Off-gassed from office equipment, electric motors, electrostatic air cleaners

Chest pain, asthma, respiratory irritations

Lead

Pipes, paint

Problems with central nervous system, kidney and blood cells; impairment of mental and physical development; convulsions, comas and death at high levels

Asbestos

Insulation

Long-term risk of chest and abdominal cancers and lung diseases


In addition to the indoor air contaminants listed above that are found in both hospitals and schools, the below chart outlines the indoor air contaminants particular to hospitals:

Indoor Air Contaminants Particular to Hospitals9

Contaminants

Sources

Adverse Effects

Formaldehyde, acetaldehyde

Off-gassed from medical disinfectants, fixatives, preservatives

Irritations to respiratory system, eyes, nose and throat; carcinogens potentially causing cancer

Glutaraldehyde

Off-gassed during sterilization process

Bodily irritation, asthma, difficulty breathing

Ethylene oxide

Off-gassed during sterilization process

Gastric irritation, liver injury, respiratory irritation, lung injury, headache, nausea, vomiting, diarrhea, shortness of breath, cyanosis, carcinogen potentially causing cancer

Aromatic hydrocarbons, such as benzene

Hand sanitizer

Carcinogen potentially causing cancer

Respirable suspended particulates, such as tiny airborne particles or aerosols (PM2.5)

Combustion, industrial processes, power generation, use of lasers and electrosurgical dissection devices

Permanent DNA mutations, heart attacks, premature death

Latex allergens

Off-gassed from latex gloves

Allergic reactions, skin irritations


The Challenge: Deficient IAQ has Many Adverse Effects on Occupants of Hospitals & Schools
Deficient IAQ has numerous adverse effects on the on the health, cognitive function, productivity and general wellbeing of all indoor occupants. Below are the adverse effects of deficient IAQ that are specific to hospitals and schools:

Adverse Effects of Deficient IAQ on Occupants of Hospitals

Increased infections

Hospital-acquired infections are a serious problem in U.S. hospitals, and the issue is aggravated by deficient IAQ, especially since many infection threats in hospitals are airborne.10 According to the Centers for Disease Control and Prevention (CDC), more than two million patients a year acquire a variety of infections in U.S. hospitals while they are hospitalized for other health problems, and that 88,000 of these patients die as a direct or indirect result. Out of these deaths, it’s estimated that about 5,000 are related to poor construction and maintenance practices, which can increase indoor air pollution.11 Furthermore, up to one-third of all hospital-acquired infections are caused by airborne contaminants—such as inorganic particles, mold and bacteria—which means that poorly ventilated hospitals suffer from greater instances of airborne infections due to their poor-quality indoor air.12

Transmitted diseases and viruses

When patients are sick, they can easily spread their diseases and viruses through the air via skin microbiota and coughing, thus contributing to deficient IAQ. In fact, patients are the source of some of the most potent contaminants in hospitals, such as MRSA.13 Therefore, it’s essential for a ventilation system to remove these diseases and viruses from the indoor air to prevent their transmission.

Aggravated patient harm

Patients are already in a vulnerable state due to their weakened condition and therefore are apt to suffer aggravated harm due to deficient IAQ. This is especially true for patients with compromised immune systems who aren’t allowed to move around a hospital due to infection risks, yet are just as exposed in their own bed to contaminants if a hospital is poorly ventilated. Moreover, according to the EPA, 50 percent of all illnesses are either caused by, or aggravated by, polluted indoor air.14

Compromised surgeries

Patients undergoing surgeries are particularly vulnerable to deficient IAQ since sensitive tissues and organs are often exposed to the air and therefore can be negatively impacted by airborne bacteria, viruses and other microbes, which can increase infections.15

Cognitive impairment of staff

Deficient IAQ causes cognitive impairment, as shown in studies by NASA, the Harvard School of Public Health and the Lawrence Berkeley National Laboratory in which CO2 negatively impacted thinking and decision-making at levels commonly found inside most buildings, including hospitals. NASA even found instances of cognitive impairment in astronauts at much lower CO2 levels than expected.16 Therefore, this means that nurses, doctors and all hospital staff are at risk of their cognitive function being seriously impaired, which can severely impact patient care.

Productivity decline for staff

Deficient IAQ causes serious losses in productivity for businesses of every type, including hospitals, due to worker sickness and absenteeism. In fact, worker absenteeism due to deficient IAQ is estimated to cost the U.S. economy $168 billion annually, according to the Building Ecology Research Group.17

Increased financial costs

According to the CDC, the overall annual direct medical costs of hospital-acquired infections to U.S. hospitals can be up to $45 billion after adjusting to 2007 dollars using the Consumer Price Index (CPI) for inpatient hospital services.18 A large amount of these financial costs can be attributed to increased instances of infections due to deficient IAQ.


Adverse Effects of Deficient IAQ on Occupants of Schools

Health problems

Deficient IAQ in schools has many adverse health effects on students, teachers and staff, including acute allergies, headaches, coughs, asthma, skin irritations and breathing difficulties, as well as chronic illnesses such as cancer, liver disease, kidney damage, nervous-system failure and even premature death. In fact, the EPA found that the presence of dampness and mold increases the risk of asthma and related adverse respiratory health effects by 30-50 percent.19

Further, the EPA determined that schools are at particular risk of deficient IAQ due to insufficient maintenance of facilities and HVAC systems. And the problem is even worse in older buildings that need constant upkeep, which characterizes the majority of the U.S.’s schools since more than 75 percent were built before 1970.20

All of these facts are particularly alarming considering so many people spend so much time inside schools. More than 55 million school children and about three million adults in the U.S.—equaling 20 percent of the country’s population—enter the nation's schools everyday.21 And the average child spends about 1,300 hours inside a school each year, while teachers and other employees spend even longer.22

Problems magnified in children

Children are disproportionately vulnerable to the adverse effects of inhaling indoor air contaminants, according to the WHO. Compared to adults, children breathe in more pollutants per pound of body weight, plus children’s airways are narrower, thus leading to greater obstruction caused by contaminants.23 What’s more, children’s immune systems are less developed and therefore provide a weaker defense when challenged.

Cognitive impairment

As noted previously, NASA, Harvard and the Lawrence Berkeley National Laboratory determined that deficient IAQ can cause cognitive impairment due to CO2 exposure. This means that anyone inside a school building, including students, teachers and staff alike, is especially at risk because of the higher-than-average occupant density of schools, and hence the greater amount of CO2.
In fact, Harvard found that, on average, a typical participant’s cognitive scores dropped 21 percent with a 400 parts per million (ppm) increase in CO2.24 And such a rise isn’t hard to reach since even though the design standard for CO2 levels in most buildings is 1000 ppm, the Lawrence Berkeley National Laboratory found average CO2 concentrations in elementary schools in California and Texas to be above 1,000 ppm, with a substantial proportion exceeding 2,000 ppm and 21 percent of Texas classrooms exceeding 3,000 ppm.25

Diminished academic performance

The EPA determined that a school’s physical environment also can play a major role in academic performance, and that negative environmental factors, such as deficient IAQ, can harm students’ ability to perform academically. Specifically the EPA found that:

  • When the school environment is unhealthy, which occurs with poor ventilation, children can be exposed to allergens, pollutants, chemicals and adverse classroom conditions that can cause their academic performance to suffer.26
  • Children in poorly ventilated classrooms tend to score lower on standardized tests in math and reading than children in classrooms with higher outdoor-air ventilation rates.27
  • Modest increases in room temperature negatively affect student's abilities to perform tasks requiring mental concentration. Supporting this notion is a study done by the Science Research Club from Westview High School in Beaverton, Oregon, which found that at the ideal indoor temperature of 72°F, students scored an average of 90 percent (out of 100) on a test, yet when the indoor temperature was increased to 81°F, average test scores dropped dramatically to 72 percent (out of 100).28

Increased absenteeism

Many students, teachers and staff alike suffer from Sick Building Syndrome (SBS), which occurs when a person experiences severe health issues and discomfort that have no other cause except for time spent in a building with deficient IAQ. In fact, the WHO found that up to 64 million U.S. workers are at risk of suffering from SBS.29 What’s more, the EPA found that schools with a major maintenance backlog have a lower average daily student attendance rate.30

The Solution: Energy Recovery Ventilation is the Best Choice for Enhancing IAQ
What’s the best way to provide cleaner and healthier air inside campus buildings, such as hospitals and schools? The answer is increased and balanced ventilation. As long as enough controlled and filtered fresh outdoor air is coming in and stale indoor air is exhausted out, indoor spaces will enjoy high-quality air. In fact, the American Lung Association states that proper ventilation is essential for keeping the air fresh and healthy indoors.31

So how can IAQ be enhanced while also minimizing costs and even generating savings? The best way is via energy recovery ventilation (ERV), which enhances IAQ while maximizing sustainability and safeguarding the environment. The ERV process optimizes energy efficiency by preconditioning the outdoor air coming in with the exhaust air’s heat and humidity that’s otherwise wasted by conventional systems. This leads to substantial reductions in energy and equipment costs, thus spurring the EPA to state that, “ERV systems provide excellent opportunities for saving energy, controlling humidity and providing sufficient outside air to promote IAQ.”32

Below are the specific benefits realized through energy recovery ventilation:

Benefits of Energy Recovery Ventilation

Cleaner and healthier indoor air

IAQ is enhanced since internally generated contaminants are removed by exhausting stale indoor air, while outdoor contaminants are prevented from entering through filtration.

HVAC energy costs are decreased by up to 40 percent

This is possible by optimizing energy efficiency, reducing HVAC loads, decreasing capital and operating costs and cutting peak demand.

Significant annual long-term energy savings

Due to optimized energy efficiency and reduced HVAC loads every year for the life of the system—which can be over 25 years—significant annual energy savings are generated over the long-term.

Increased structural asset value and longevity

When buildings suffer from deficient IAQ, not only are indoor occupants feeling the adverse effects, but a poor indoor environment also produces a diverse assortment of potentially negative impacts on the asset value and longevity of the structure. For example, the growth of microbiological organisms might be encouraged, mold might be more apt to propagate, upkeep and maintenance demands could increase and premature construction-material failure could be more common, just to name a few damaging scenarios. Enhanced IAQ assists in preserving the overall health and integrity of the actual structure, thus increasing its asset value and longevity.

Lowered capital and operating costs

By downsizing HVAC equipment and streamlining operations, capital and operating costs are lowered.

Strengthened sustainability

Less HVAC energy used means a reduced environmental footprint, which strengthens sustainability efforts.

The Results: Enhanced IAQ Improves the Health, Cognitive Function, Productivity & Wellbeing of Hospital & School Occupants
Enhancing IAQ energy-efficiently, cost-effectively and sustainably through energy recovery ventilation results in numerous benefits for the occupants of hospitals and schools. Below are the specific benefits achieved for each building type as a result of providing cleaner and healthier indoor air:

Benefits of Enhanced IAQ for Occupants of Hospitals

Reduced infections

According to the CDC, 70 percent of hospital-acquired infections are preventable.33 Indoor air contaminants are a primary contributor to increased infection rates, and therefore, by enhancing IAQ, the number of hospital-acquired infections can be reduced. Along these lines, the Center for Health Design found that:

  • Providing clean filtered air and effectively controlling indoor air pollution through ventilation are two key aspects of maintaining good air quality, which is possible through the use of HEPA filters since they’re highly effective in preventing airborne infections from entering the hospital environment.34

  • Controlling airflow, temperature and humidity in hospitals can help maintain excellent IAQ, which can help control the growth of molds, bacteria, viruses and other pathogens that can cause infections and diseases.35

Faster patient recovery

According to a study by Texas A&M University, patients in a controlled indoor environment with high-level IAQ have more rapid physical improvement compared to patients in an uncontrolled environment.36 Maintaining the right temperature can also help create an indoor environment that promotes healing and prevents pathogens from growing and spreading.37

Boosted staff productivity

Higher-quality indoor air results in healthier doctors, nurses and support staff, thus reducing sickness and absenteeism. In addition to better health, workers will also experience improved cognitive function, thus further boosting productivity. In fact, another Harvard study found that doubling the rate of a conventional ventilation system from 20 CFM per person (the rate recommended by ASHRAE) to 40 CFM per person only costs about $32 per person, per year and leads to a productivity increase of $6,500 per person, per year. And if an ERV system is added, the anticipated increase in energy costs can be reduced by up to 60 percent.38

Financial savings

Reducing infections through enhanced IAQ can go a long way in generating significant financial savings for hospitals. In fact, according to the Pennsylvania Patient Safety Authority, preventing 70 percent of all infections in the U.S. could translate into potential savings of up to $31.5 billion per year, and increased ventilation can play an integral role in eliminating many of these infections.39

Benefits of Enhanced IAQ for Occupants of Schools

Better health for students, teachers and staff

By breathing cleaner and healthier indoor air all day long at school, students, teachers and staff will experience fewer short- and long-term health problems, which is an important achievement considering the WHO determined that in 2012, 4.3 million deaths globally were attributable to indoor air pollution.40

Strengthened cognitive function

By removing contaminants from the air inside schools, students, teachers and staff will improve their overall cognitive function, thus achieving more coherent thinking and decision-making. Specifically, a Harvard study found that, on average, when compared to an indoor environment with deficient IAQ (high VOC concentration), cognitive scores were 61 percent higher in a simulated green-building environment (low VOC concentration) and 101 percent higher in a simulated green-building environment coupled with doubling the outdoor-air ventilation rate from 20 CFM per person to 40 CFM per person.41

Improved test scores

The EPA found that improvements in school environmental quality can enhance academic performance, and that children in classrooms with high outdoor-air ventilation rates tend to score better on standardized tests in math and reading than children in poorly ventilated classrooms.42 Specifically the EPA found that:

  • Doubling classroom ventilation rates could improve standardized test scores by about 10 percent.43

  • Test scores uniformly increase as building conditions improve, such as improving ventilation systems. Specific results depend on the type of test and the degree of difference in building conditions, but the overall increase in test scores can be from three to 17 percent.44
  • Reduced absenteeism

    Enhanced IAQ leads to fewer sick days for students, teachers and staff. Specifically, the EPA found that raising classroom outdoor-air ventilation rates can reduce absenteeism by approximately five to 10 absences per 1,000 students for a 1,000 ppm decrease in the difference between indoor and outdoor CO2 levels.45

    In Sum
    Campus buildings, in particular hospitals and K-12 schools, are at tremendous risk of suffering from deficient IAQ and all of its ensuing adverse effects, especially with increased air-sealing methodologies on the rise. By enhancing IAQ, the benefits to indoor occupants of hospitals and schools are numerous, including improved health, cognitive function, productivity and wellbeing—and this can all be achieved energy-efficiently, cost-effectively and sustainably through energy recovery ventilation

    Finally, as RenewAire ERV systems have reached their fifth generation of development, and with the efficacies we’ve achieved today, we can rationalize ventilation designs in these facilities that utilize 100 percent outdoor air since this costs the same as conventional infrastructures that typically use only 20 percent outdoor air. Therefore, there’s no argument against installing ERV systems in every hospital and school so building occupants can be the beneficiaries of increased and balanced ventilation.

    To learn more about how energy recovery ventilation can enhance IAQ in your hospital or school, contact RenewAire by clicking here.


    Nick Agopian is Vice President of Sales and Marketing at RenewAire, a pioneer in enhancing indoor air quality in commercial and residential buildings of all sizes through high-efficiency, enthalpic-core, static-plate ERV systems. For more information, visit: www.renewaire.com.

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    1 All EPA facts from this paragraph are sourced from: “Why Indoor Air Quality is Important to Schools,” EPA, https://www.epa.gov/iaq-schools/why-indoor-air-quality-important-schools.

    2 “Burden of disease from ambient and household air pollution,” World Health Organization (WHO), http://www.who.int/phe/health_topics/outdoorair/databases/en/.

    3 Indoor Air Pollution: Introduction for Health Professionals,” U.S. Consumer Product Safety Commission, http://www.cpsc.gov/en/Safety-Education/Safety-Guides/Home/Indoor-Air-Pollution-Introduction-for-Health-Professionals/.

    4 M. Ramaswamy, Farooq Al-Jahwari, Saif M. Masoud Al-Rajhi, “IAQ in Hospitals—Better Health through Indoor Air Quality Awareness,” Texas A&M University, 2010, https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/94139/ESL-IC-10-10-88.pdf?sequence=1&isAllowed=y .

    5 Dan Pollock, “Surgical Suite: Creating the Optimal Environment,” Trane, October 2009, https://www.trane.com/content/dam/Trane/Commercial/global/markets/healthcare/Surgical_Suite.pdf.

    6 “Air Indoor Resources,” Florida Department of Education, http://www.fldoe.org/finance/edual-facilities/air-indoor-resources.stml.

    7 “Indoor Air Quality (IAQ) in Schools,” Minnesota Department of Health, http://www.health.state.mn.us/divs/eh/indoorair/schools/.

    8 Sources: U.S. Environmental Protection Agency (EPA), U.S. Centers for Disease Control and Prevention (CDC), Canadian Centre for Occupational Health and Safety (CCOHS), Occupational Safety & Health Administration (OSHA), Wikipedia.

    9 Sources: U.S. Environmental Protection Agency (EPA), U.S. Centers for Disease Control and Prevention (CDC), Canadian Centre for Occupational Health and Safety (CCOHS), Occupational Safety & Health Administration (OSHA), Wikipedia.

    10 Laura Rygielski Preston, “Breath of fresh air: Indoor air quality critical to effective infection control,” Medical Construction & Design, January/February 2011, https://www.trane.com/content/dam/Trane/Commercial/global/markets/healthcare/FdMCD0111_52-54-IF-IAQ.PDF.

    11 D. Riley, J. Freihaut, W. P. Bahnfleth, Z. Karapatyan, “Indoor Air Quality Management and Infection Control in Health Care Facility Construction,” Penn State College of Engineering, 2004, http://www.engr.psu.edu/iec/publications/papers/indoor_air_quality.pdf.

    12 Dan Pollock, “Surgical Suite: Creating the Optimal Environment,” Trane, October 2009, https://www.trane.com/content/dam/Trane/Commercial/global/markets/healthcare/Surgical_Suite.pdf.

    13 Christopher J. Stipe, “Indoor air quality in hospitals,” Consulting-Specifying Engineer, July 14, 2015, http://www.csemag.com/single-article/indoor-air-quality-in-hospitals/b4a355bfbd61c4902f08216c20be3e8e.html.

    14 Mike Barrett, “Indoor Air Pollution Could Cause 50 Percent of Illnesses Globally,” Natural Society, October 21, 2011, http://naturalsociety.com/indoor-air-pollutants-cause-50-of-illnesses-globally/.

    15 Andrew J. Streifel, “A Guide to Best Practices in Hospital IAQ,” ACHR News, November 19, 2007, http://www.achrnews.com/articles/105354-a-guide-to-best-practices-in-hospital-iaq.

    16 Joe Romm, “Exclusive: Elevated CO2 Levels Directly Affect Human Cognition, New Harvard Study Shows,” Climate Progress, October 26, 2015, http://thinkprogress.org/climate/2015/10/26/3714853/carbon-dioxide-impair-brain/.

    17 Hal Levin, “Commercial Building Indoor Air Quality: Introduction to the Problem,” Building Ecology, November 1999, http://www.buildingecology.com/articles/commercial-building-indoor-air-quality-introduction-to-the-problem/.

    18 R. Douglas Scott II, “The Direct Medical Costs of Healthcare-Associated Infections in U.S. Hospitals and the Benefits of Prevention,” Centers for Disease Control and Prevention (CDC), March 2009, http://www.cdc.gov/hai/pdfs/hai/scott_costpaper.pdf.

    19 “How Does Indoor Air Quality Impact Student Health and Academic Performance?,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/how-does-indoor-air-quality-impact-student-health-and-academic-performance.

    20 Sherry Everett Jones, PhD, MPH, JD, Nancy D. Brener, PhD, Tim McManus, MS, “Prevalence of School Policies, Programs, and Facilities That Promote a Healthy Physical School Environment,” American Journal of Public Health, September 2003, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448012/#r4.

    21 “Healthy Schools: Environmental Factors, Children’s Health and Performance, and Sustainable Building Practices,” U.S. Environmental Protection Agency, October 8, 2013, https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.rfatext/rfa_id/568.

    22 “Healthy Schools: Environmental Factors, Children’s Health and Performance, and Sustainable Building Practices,” U.S. Environmental Protection Agency, October 8, 2013, https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.rfatext/rfa_id/568.

    23 “Children's Health and the Environment,” World Health Organization (WHO), July 2008, http://www.who.int/ceh/capacity/Indoor_Air_Pollution.pdf.

    24 Joe Romm, “Exclusive: Elevated CO2 Levels Directly Affect Human Cognition, New Harvard Study Shows,” Climate Progress, October 26, 2015, http://thinkprogress.org/climate/2015/10/26/3714853/carbon-dioxide-impair-brain/.

    25 Joe Romm, “Exclusive: Elevated CO2 Levels Directly Affect Human Cognition, New Harvard Study Shows,” Climate Progress, October 26, 2015, http://thinkprogress.org/climate/2015/10/26/3714853/carbon-dioxide-impair-brain/.

    26 “About the State School Environmental Health Guidelines,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/schools/about-state-school-environmental-health-guidelines.

    27 “Evidence from Scientific Literature about Improved Academic Performance,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/evidence-scientific-literature-about-improved-academic-performance.

    28 Josean Perez, Julio Montano, Jose Perez, “Healthy Schools as a Learning Tool,” Healthy Schools, http://healthyschools.cefpi.org/index.html.

    29 William Fisk, “How IEQ Affects Health, Productivity,” ASHRAE Journal, 2002, https://publications.lbl.gov/islandora/object/ir%3A120146/datastream/PDF/download/citation.pdf.

    30 “How Does Indoor Air Quality Impact Student Health and Academic Performance?,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/how-does-indoor-air-quality-impact-student-health-and-academic-performance.

    31 “Ventilation: How Buildings Breathe,” American Lung Association, http://www.lung.org/our-initiatives/healthy-air/indoor/at-home/ventilation-buildings-breathe.html.

    32 “Indoor Air Quality and Energy Efficiency,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/indoor-air-quality-iaq/indoor-air-quality-and-energy-efficiency.

    33 Laura Rygielski Preston, “Breath of fresh air: Indoor air quality critical to effective infection control,” Medical Construction & Design, January/February 2011, https://www.trane.com/content/dam/Trane/Commercial/global/markets/healthcare/FdMCD0111_52-54-IF-IAQ.PDF.

    34 Anjali Joseph, Ph.D., “Impact of the Environment on Infections in Healthcare Facilities,” The Center for Health Design, 2006, https://www.healthdesign.org/chd/research/impact-environment-infections-healthcare-facilities.

    35 Anjali Joseph, Ph.D., “Impact of the Environment on Infections in Healthcare Facilities,” The Center for Health Design, 2006, https://www.healthdesign.org/chd/research/impact-environment-infections-healthcare-facilities.

    36 M. Ramaswamy, Farooq Al-Jahwari, Saif M. Masoud Al-Rajhi, “IAQ in Hospitals—Better Health through Indoor Air Quality Awareness,” Texas A&M University, 2010, https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/94139/ESL-IC-10-10-88.pdf?sequence=1&isAllowed=y .

    37 Laura Rygielski Preston, “Breath of fresh air: Indoor air quality critical to effective infection control,” Medical Construction & Design, January/February 2011, https://www.trane.com/content/dam/Trane/Commercial/global/markets/healthcare/FdMCD0111_52-54-IF-IAQ.PDF.

    38 Piers MacNaughton, James Pegues, Usha Satish, Suresh Santanam, John Spengler and Joseph Allen, “Economic, Environmental and Health Implications of Enhanced Ventilation in Office Buildings,” International Journal of Environmental Research and Public Health, November 18, 2005, http://www.mdpi.com/1660-4601/12/11/14709/html.

    39 Kelly M. Pyrek, “Understanding HAI Burden, Demonstrating ROI Essential to Making a Business Case,” Infection Control Today, November 13, 2013, http://www.infectioncontroltoday.com/articles/2013/11/understanding-hai-burden-demonstrating-roi-essential-to-making-a-business-case.aspx.

    40 "Burden of disease from ambient and household air pollution,” World Health Organization (WHO), http://www.who.int/phe/health_topics/outdoorair/databases/en/.

    41 Joseph G. Allen, Piers MacNaughton, Usha Satish, Suresh Santanam, Jose Vallarino and John D. Spengler, “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, October 26, 2015, http://ehp.niehs.nih.gov/wp-content/uploads/advpub/2015/10/ehp.1510037.acco.pdf.

    42 “How Does Indoor Air Quality Impact Student Health and Academic Performance?,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/how-does-indoor-air-quality-impact-student-health-and-academic-performance.

    43 “Frequently Asked Questions about Improved Academic Performance,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/frequently-asked-questions-about-improved-academic-performance#IAQIAP_Maintenance.

    44 “Frequently Asked Questions about Improved Academic Performance,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/frequently-asked-questions-about-improved-academic-performance#IAQIAP_Maintenance.

    45 “Frequently Asked Questions about Improved Academic Performance,” U.S. Environmental Protection Agency (EPA), https://www.epa.gov/iaq-schools/frequently-asked-questions-about-improved-academic-performance#IAQIAP_Maintenance.