SummaryStudents identify types and sources of indoor air pollutants in their school and home environments. They evaluate actions that can be taken to reduce and prevent poor indoor air quality. In an associated literacy activity, students develop a persuasive peer-to-peer case against smoking with the goal to understand how language usage can influence perception, attitudes and behavior.
Indoor air pollutants can cause a variety of health impacts ranging from breathing complications to cancer. Mechanical engineers who design heating, venting and air conditioning systems for buildings continually work to improve indoor air quality. Their HVAC systems bring fresh outdoor air into circulation to keep low the concentrations of contaminants from cleaning products, paints, perfumes, people, smoking, textiles and construction material off-gassing. Other engineers design non-toxic cleaning supplies and paints, improved air filters and carbon monoxide detectors.
A basic understanding of visible and invisible air pollution.
After this lesson, students should be able to:
- Identify types and sources of indoor air pollutants (IAP).
- Know some methods of counteracting and/or preventing IAP.
- Describe how engineers interact with indoor air pollutants.
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Each TeachEngineering lesson or activity is correlated to one or more K-12 science,
technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN),
a project of D2L (www.achievementstandards.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics;
within type by subtype, then by grade, etc.
Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.
Bring to the classroom the following items to stimulate an open discussion about indoor air pollution:
- vacuum cleaner with a hose attachment
- 1 white facial tissue
- 1 rubber band
- air filter from a home furnace (or school furnace; arrange to take a mini field-trip to view it)
- home carbon monoxide (or smoke) detector
Display the air filter and carbon monoxide detector so all students can see them. Ask the students to make suggestions about how these two items are related. (Answer: They are both related to controlling indoor air pollution or air quality.) If the students do not see the connection, continue on with the demonstration and return to the question later.
Ask the students to describe whether or not they think the air in the classroom is "polluted." They may remember information about visible and invisible air pollution learned during the activities in Air Pollution unit, Lesson 2 and Lesson 3.
To show that that there are pollutants in the air, place the white facial tissue over the vacuum hose opening and secure it tightly with the rubber band. Turn the vacuum on and gently wave the hose around in the air for about one minute. Turn the vacuum off and carefully remove the tissue. Have students examine the tissue for particles (you may need a magnifying glass to see some of them).
Explain to students that the vacuum demonstration is related to the air filter on display. Can they explain how? Can they see the connection between the air filter and the carbon monoxide detector?
Once students see the connection, ask them to think of other examples of items they use in their lives that are related to indoor air pollution and air quality. (Possible answers: Exhaust fans in the kitchen/bathroom/laundry room, smoke detectors, plants, ionizers, air fresheners, breath fresheners, etc.). The devices were designed by engineers to improve the condition of the air you breathe!
Lesson Background and Concepts for Teachers
During a time when significant steps are being made to reduce outdoor air pollution, the hazards from indoor air pollution (IAP) are actually increasing! In 1992, IAP was designated as one of the world's four most pressing environmental problems by the World Bank.
Indoor air pollution is especially hazardous in rural areas of developing countries due to the increasing number of people burning traditional fuels, such as coal, oil, wood and dung. In the U.S., the increasing hazard is a result of newer homes being built "tighter" for more efficient heating and cooling. Houses with fewer drafts and cracks also have reduced ventilation, so air pollutants tend to store and concentrate inside. While it is true that outdoor pollution is another contributor to IAP, this lesson focuses on sources of pollution located inside a building.
Common Indoor Air Pollutants
Refer to Table 1 to learn the source and adverse health effects for many common indoor air pollutants.
Indoor air pollutants can be created within a building or drawn inside from outdoor sources. If these pollutant sources are not controlled, indoor air quality dilemmas can arise. Air pollutants often travel from their source throughout a building by means of human activity, HVAC (heating, ventilation and air conditioning) systems and natural ventilation (wind). Indoor air pollutants sources include:
- Equipment (improper venting and/or filtration of HVAC systems, emissions from office equipment and laboratories)
- Dust-producing or water-damaged materials
- Unsanitary trash emissions
- Insects and pests
- Food preparation areas
- Cleaning materials
- People and pets
How Do Air Pollutants Affect Us?
IAPs may cause a variety of adverse health effects ranging from rashes and eye irritation to cancer, breathing complications (such as asthma), kidney failure, liver damage and birth defects. The degree of the adverse health effects depends on the magnitude and frequency of exposure to the pollutant(s). The fact that pollutants tend to affect different people in different ways and to varying degrees is compounded by the fact that many effects from poor indoor air quality are often vague symptoms, rather than clearly defined illnesses. Some typical symptoms associated with inadequate indoor air quality include headaches, fatigue, shortness of breath, coughing, sneezing, eye and nose irritation, and dizziness.
How Can We Prevent and Control Indoor Air Pollution?
- Do not smoke.
- Use non-toxic cleaning products and art supplies.
- Increase the number of houseplants (they absorb pollutants).
- Improve overall air circulation (especially with outdoor air).
- Ensure that air ducts and ventilation systems are functioning optimally.
- Use air filters or air cleaners that are sized appropriately for the living area.
- Do not use unvented natural gas appliances. Make sure your natural gas stove or fireplace is vented.
- Install carbon monoxide detectors and smoke detectors.
- Install exhaust fans in the bathrooms (to reduce the humidity).
HVAC: An acronym for heating, ventilating and air conditioning.
indoor air pollution: The gases and particles that affect the quality of the air inside our buildings. Abbreviated as IAP.
volatile organic compound: An organic chemical containing carbon that escapes into the air easily. Abbreviated as VOC. Many VOCs are also hazardous air pollutants that can cause serious illnesses. Carbon is the basic chemical element found in living beings; carbon-containing chemicals are called organic. Example VOCs include some hairspray, air fresheners and paints.
- The Search for Secret Agents - Students embark on a scavenger hunt around the school looking for indoor air pollution and mapping source locations.
- Smoke and Mirrors - In this literacy activity, students develop a persuasive peer-to-peer case against smoking. The goal is to understand how language usage can influence perception, attitudes and behavior.
- Sensing Air Pollution - Students learn about electricity and air pollution while building devices to measure volatile organic compounds (VOC) by attaching VOC sensors to prototyping boards.
Now that students have found some examples of indoor air pollution in their school and home, and better understand the associated health risks, ask them to begin thinking about what they can do to help prevent these types of pollutants.
Conclude by conducting the onion and lemon juice class demonstration described at the end of the Assessment section.
Discussion Question: Display the air filter and carbon monoxide detector so all students can see them. Ask students: How might these two items be related? (Answer: They are both related to indoor air pollution, improving it and monitoring it.) If they do not see the connection, continue with the demonstration and come back to the question later.
Brainstorming: As a class, have the students engage in open discussion. Remind students that in brainstorming, no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Have them raise their hands to respond. Write their ideas on the board.
- What everyday items in your life are related to indoor air pollution and air quality? (Possible ideas: Exhaust fans in the kitchen/bathroom/laundry room, smoke detectors, plants, ionizers, air fresheners, breath fresheners, etc.)
Lesson Summary Assessment
Demonstration / Engineering Recommendation: Conduct a closing demonstration with the entire class. Materials include: 1 fresh onion, lemon juice, 1 kitchen knife, 1 cutting board, 1 plate. Procedure:
- Slice the onion and place a slice on the plate. The smell should "pollute" the air. Carry the onion around the room for those who would like to smell it more closely. Ask the students: Is the strong smell unpleasant? Does it make your eyes water? Has the onion affected the air quality in the room?
- Pour lemon juice over the onion, completely covering all parts of it.
- Ask the students: Is the onion smell as strong? Does it still make your eyes water? (Answer: The onion smell should be considerably less strong.)
- Tell the students that they are now engineers for a large chain of food stores. Ask them to write a recommendation to the owners for the following questions:
- What does this demonstration have to do with indoor air pollution?
- If you were an engineer and you had just discovered that lemon juice counteracts the strong smell of onions (and other strong smells as well, such as garlic and fish), what recommendations could you make with the information?
Lesson Extension Activities
Read and discuss the attached Radon Reading.
Have students explore in more detail what they observed in the onion/lemon juice class demonstration (described in the Assessment section). Do all citrus fruits work? Does the lemon work on other smells, as well (fish, garlic, etc.)? Can you use this information to develop a "breath freshening" suggestion for someone who has just eaten a strong smelling food?
Have each student (to student group) choose a particular indoor air pollutant to research. Have each make an awareness poster about that pollutant. Display the posters in the school common area.
See the U.S. Environmental Protection Agency's Indoor Air Quality Tools for Schools Program at www.epa.gov (or attached) for ideas about how to use their resources with your students. Especially note the age appropriate activities in the How to Use the Tools for Schools Curriculum & Activities for Grades K-3 link.
Now that the students have found some examples of indoor air pollution in their own school and home. Ask them to begin thinking about what they can do to help prevent these types of pollutants. Have them search the Internet for an example of air pollution prevention. Conduct a class discussion on this topic during the next class period.
Air – Indoor Air Quality (IAQ). Updated September 13, 2004. U.S. Environmental Protection Agency. Accessed September 15, 2004. www.epa.gov.
Bonnet, Bob and Keen, Dan. Science Fair Projects – The Environment. New York, NY: Sterling Publishing Company, Inc., 1995.
Indoor Air Pollution. EduGreen: Making Environmental Learning Fun for the Young. Accessed September 15, 2004. http://edugreen.teri.res.in/explore/air/indoor.htm.
Jennett, Pamela Spurling. Investigations in Science – Ecology. Huntington Beach, CA: Creative Teaching Press, Inc., 1995.
ContributorsAmy Kolenbrander; Janet Yowell; Natalie Mach; Malinda Schaefer Zarske; Denise W. Carlson
Copyright© 2004 by Regents of the University of Colorado
Supporting ProgramIntegrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder
The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.
Last modified: June 6, 2017