Why Clean Air Matters
Learning Objectives
Students will be able to:
- Identify sources and health effects of indoor air pollution
- Explain why indoor air quality matters for health and cognition
- Describe the engineering challenge of cleaning indoor air
- Generate criteria for an effective air cleaning solution
Materials Needed
| Item | Quantity | Notes |
|---|---|---|
| PM2.5 facts handout | Class set | |
| Air quality scenario cards | 1 set per group | |
| Chart paper or whiteboard | 1 per group | For brainstorming |
| CO2 or PM sensor (optional) | 1 | For demonstration |
Lesson Overview
Engage (10 min)
Begin with a provocative question: "Is the air in this classroom making you less smart?" Introduce the concept that indoor air quality affects not just health, but cognitive performance. If available, show current CO2 or PM2.5 readings.
Explore (12 min)
Students examine air quality scenario cards in groups. Each card presents a real-world indoor air quality problem (classroom, home kitchen, hospital waiting room). Groups identify pollution sources, potential health effects, and who is most vulnerable.
Explain (10 min)
Direct instruction on PM2.5: what it is, where it comes from, why it's dangerous. Cover key facts: particles small enough to enter bloodstream, effects on lungs, heart, brain. Introduce the concept of indoor vs. outdoor sources.
Elaborate (10 min)
Engineering challenge introduction: "How might we clean the air in a classroom affordably?" Groups brainstorm potential solutions and begin developing criteria: effectiveness, cost, noise, ease of use, safety.
Evaluate (3 min)
Exit ticket: (1) Name two sources of indoor air pollution. (2) Why is PM2.5 particularly dangerous? (3) What criteria matter for an air cleaning solution in a school?
Key Vocabulary
| Term | Definition |
|---|---|
| PM2.5 | Particulate matter smaller than 2.5 micrometers; can enter lungs and bloodstream |
| Indoor air quality | The condition of air inside buildings, including pollutant levels |
| Criteria | Standards by which something is judged; requirements for success |
| Constraints | Limitations or restrictions on a design solution |
Teacher Notes
This lesson sets up the engineering design challenge that drives the entire unit. The goal is to create urgency and personal relevance. When possible, use real-time sensor data to show students that air quality is measurable and variable.
Common misconception: Students often think indoor air is cleaner than outdoor air. In reality, indoor air can be 2-5 times more polluted due to limited ventilation and concentrated sources.