The Invisible Classroom: Why School IAQ Matters for Health and Learning

Welcome to CSIAQA Module 1

Welcome, students, to Module 1 of the Certified School Indoor Air Quality Awareness (CSIAQA) course. This module focuses on something fundamental yet often overlooked: the air we breathe inside classrooms. You’ll learn what indoor air quality (IAQ) is, why it’s especially critical for children, the pollutants commonly found in schools, and how air quality affects both health and learning.

By the end of this module, you’ll understand:

• What IAQ is and how it differs from outdoor air quality
• Why school environments pose unique IAQ challenges
• Why children are more vulnerable to indoor pollutants
• What common pollutants exist in classrooms and their effects
• How poor IAQ harms health and learning
• Key real-world data and expert insights

1. What Is Indoor Air Quality (IAQ)?

Definition: IAQ refers to the quality of air inside buildings, especially as it affects the health and comfort of occupants. According to the U.S. EPA, indoor pollutant levels can be 2–5 times higher than outdoor air, and sometimes up to 100 times higher.

Why This Matters in Schools:

• People spend 90% of their time indoors
• Schools can have 4x more people per square foot than offices
• Older infrastructure, outdated HVAC systems, and tight budgets all create IAQ risks

Key IAQ Factors:

• Pollutant Sources: e.g., new flooring, cleaning agents
• Ventilation: Low air exchange rates allow pollutants to accumulate
• Building Behavior: Humidity, materials, and window use all play a role

Note: External air quality also impacts indoor conditions. Pollutants from highways, factories, or wildfire smoke can infiltrate classrooms.

Deeper Issue: School IAQ problems often stem from systemic underfunding, deferred maintenance, and aging infrastructure. This makes IAQ not just an invisible issue, but a neglected one tied to broader education investment challenges.

“Sick Building Syndrome”:

• A term describing buildings that cause physical symptoms (headaches, fatigue, etc.) that resolve when people leave the building
• Indicates how air quality affects overall comfort and performance, not just disease

2. Why Children Are More Vulnerable

Children are more sensitive to indoor air pollutants for several reasons:

Biological Vulnerability:

• Developing lungs and immune systems
• Higher breathing rates (more air per kg of body weight)
• Greater oral breathing (deeper pollutant penetration)

Behavioral Patterns:

• Spend long hours in school
• Are more physically active
• Breathe closer to the floor where some pollutants settle

Chronic Impacts:

• Exposure can affect lung and brain development
• Linked to asthma, neurodevelopmental disorders, and lower IQ
• Long-term consequences can extend into adulthood

“Children can do little to change the situation or protect themselves” — placing a moral responsibility on adults to advocate and act

3. Common School IAQ Pollutants

Pollutants often come from inside school buildings. Here are the most common types:

1. Dust

• Sources: Skin cells, fabric, soil, mites, pet dander, mouse droppings
• Effects: Allergies, asthma

2. Mold

• Sources: Leaks, high humidity, water damage
• Effects: Asthma, respiratory infections, allergic rhinitis

3. VOCs (Volatile Organic Compounds)

• Sources: Paints, glues, furnishings, cleaners, air fresheners
• Effects: Dizziness, irritation, fatigue, attention deficits

4. Carbon Dioxide (CO₂)

• Sources: Human respiration, overcrowding, combustion
• Effects: Headaches, poor memory, nausea, lower test scores

5. Allergens

• Sources: Mold, pests, pet dander, outdoor pollen
• Effects: Asthma, allergic reactions, absenteeism

6. Particulate Matter (PM10, PM2.5)

• Sources: Combustion, traffic, wildfires
• Effects: Cognitive decline, asthma, heart disease

7. Other Notable Pollutants:

• Radon Gas: Cancer-causing, enters through building foundations
• NO₂ (Nitrogen Dioxide): Traffic-related, exacerbates asthma
• CO (Carbon Monoxide): Lethal in high doses, comes from fuel appliances
• Asbestos: Found in old materials, causes lung disease
• Secondhand Smoke: Linked to cognitive decline
• Heavy Metals (Lead, Mercury): Neurotoxic, impact IQ and behavior

In real-world classrooms, students are exposed to mixtures of pollutants, not isolated contaminants. This “invisible cocktail” can amplify health effects.

4. Health Impacts of Poor IAQ

Immediate Symptoms:

• Eye, nose, throat irritation
• Drowsiness, fatigue, dizziness
• Difficulty concentrating

Asthma:

• Affects 1 in 13 students
• Major cause of absenteeism
• Triggered by mold, dust, pets, chemicals

Respiratory Infections:

• Linked to absenteeism and performance decline

Long-Term Health Risks:

• Lung development issues
• Chronic asthma and allergies
• Cancer (from radon), cardiovascular disease

Investing in better IAQ improves attendance, health, and even school funding (via ADA budgets).

5. Cognitive and Learning Effects

Pollution Affects Thinking:

• VOCs, CO₂, NO₂, and PM2.5 reduce attention, reaction time, and memory
• High CO₂ causes mental fog, poor problem-solving, fatigue
• Poor ventilation linked to lower test scores

Long-Term Risks:

• Neurodevelopmental disorders
• Lower IQ, long-term cognitive impairment

Even a motivated student cannot reach full potential in a polluted classroom. Poor IAQ is an invisible barrier to learning.

Key Takeaway: Improving IAQ enhances student performance, health, and long-term success. It is a foundational requirement for effective education.

6. Real-World Insights and Statistics

EPA (USA):

• Half of U.S. schools have IAQ problems
• Indoor air can be 2–100x more polluted than outdoor air
• Promotes “High Performance Schools” with strong IAQ as a core feature

WHO (Global):

• Children highly vulnerable to indoor pollution
• PM2.5 linked to pneumonia deaths in children under 5

Health Canada & Canadian Studies:

• Poor IAQ found in classrooms with no ventilation
• CO₂ levels in some rooms reached 2780 ppm (well above comfort standards)
• High CO₂ correlated with reduced student comfort and cognitive function

Summary Table: School Pollutants

Final Thoughts

This module demonstrates that IAQ is a crucial but often overlooked element of a healthy learning environment. It is not just about comfort—it affects everything from asthma to academic performance. Children cannot change these conditions, so it’s up to informed adults to act.

By understanding the wide-ranging impacts of school air quality, you are now better prepared to advocate for healthier classrooms. Cleaner air supports healthier students—and healthier students are better learners.