Air Quality Index



Grade Level & Subject: Grades 9-12: Science

Length: 1 – 3 class periods


After completing this lesson, students will be able to:

  • Describe various causes and effects of air pollution on the environment, public health, etc.
  • Understand how scientists determine air quality level standards
  • Determine real-life ways to reduce air pollution levels and ways to implement these into students’ own lives.

National Standards Addressed:

This lesson addresses the following National Education Standards:[1]

  • Content Standard: NS.9-12.1 SCIENCE AS INQUIRY

As a result of their activities in grades 9-12, all students should develop:

  • Abilities necessary to do scientific inquiry
  • Understandings about scientific inquiry
  • Content Standard:NS.9-12.5 SCIENCE AND TECHNOLOGY

As a result of their activities in grades 9-12, all students should develop:

  • Abilities of technological design
  • Understandings about science and technology

As a result of their activities in grades 9-12, all students should develop an understanding of:

  • Personal and community Health
  • Population growth
  • Natural resources
  • Environmental quality
  • Natural and human-induced hazards
  • Science and technology in local, national, and global challenges
  • Content Standard:NT.K-12-5 TECHNOLOGY RESEARCH TOOLS

As a result of their activities in grades 9-12, all students should develop an understanding of:

  • Students use technology to locate, evaluate, and collect information from a variety of sources

As a result of their activities in grades 9-12, all students should develop an understanding of:

  • Students use technology resources for solving problems and making informed decisions.
  • Materials Needed:
  • Microscope slides
  • Markers
  • Rulers
  • Masking tape
  • Self-adhesive labels
  • Microscopes or magnifying glasses
  • Petroleum jelly OR double-sided tape
  • Reproducible #1 – “Air Quality Index. How Healthy is the Air You Breathe?” (accompanying PowerPoint)
  • Reproducible #2 – How Healthy is the Air You Breathe
  • Reproducible #3 – How Healthy is the Air You Breathe – Answer Key
  • Reproducible #4– Particulate Pollution Lab Report
  • Reproducible #5– Particulate Pollution Lab Report – Answer Key

Students will be assessed through the following activities:

  • Participation in class discussion and class activities
  • Completion of Reproducible #2 – How Healthy is the Air You Breathe
  • Completion of Reproducible #4 – Particulate Pollution Lab Report



Relevant Vocabulary:

  • Air pollution: Air pollution occurs when the air contains gases, dust, fumes or odor in harmful amounts. That is, amounts which could be harmful to the health or comfort of humans and animals or which could cause damage to plants and materials. The substances that cause air pollution are called pollutants. Pollutants that are pumped into our atmosphere and directly pollute the air are called primary pollutants. Primary pollutant examples include carbon monoxide from car exhausts and sulfur dioxide from the combustion of coal. Further pollution can arise if primary pollutants in the atmosphere undergo chemical reactions. The resulting compounds are called secondary pollutants. Photochemical smog is an example of this.[2]
  • Air Quality Index: A measure of the quantity of harmful particles and chemicals in the air.[3]
  • Air Quality Standard: The prescribed level of a pollutant in the outside air that should not be exceeded during a specific time period to protect public health. Established by both federal and state governments.[4]
  • Carbon monoxide:A colorless odorless very toxic gas CO that is formed as a product of the incomplete combustion of carbon or a carbon compound.[5]
  • Environmental Protection Agency (EPA): An agency established in 1970 by the United States government to coordinate federal programs aimed at combating pollution and protecting the environment.[6]
  • Ground-level ozone: A substance created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC.[7]
  • Nitrogen dioxide: A toxic reddish browngas NO2 that is a strong oxidizing agent, is produced by combustion (as of fossilfuels), and is an atmospheric pollutant (as in smog)[8]
  • Particulate: Of or relating to minute separate particles.[9]
  • Standards:Something established by authority, custom, or general consent as a model or example.[10]
  • Sulfur dioxide: A heavy pungent toxic gas SO2 that is easily condensed to a colorless liquid, is used especiallyin making sulfuric acid, in bleaching, as a preservative, and as a refrigerant, and is a major air pollutantespecially in industrial areas9

Background Information:

Air pollutionaffects all things, both natural and man-made, on the planet.  This type of pollution is often colorless and/or odorless, so it must be monitored through specific means in order to protect people, animals, vegetation, and infrastructure from harmful side effects. Air pollution not only takes the form of highway smog and acid rain, but also exists within homes and in seemingly pristine wilderness areas.

Air pollution has been shown to contribute to health problems, such as asthma, lung cancer and bronchitis, which is especially harmful for more susceptible sectors of the population, including young children and seniors. As a response to the increased appearance of pollution in 1970 and as health problems arose, the United States founded the Environmental Protection Agency to monitor air quality around the country. This agency was mandated to educate and protect the public while also searching for ways to reduce pollution.

One way the EPA monitors air pollution is through the ‘Air Quality Index’ (AQI). The AQI helps quantitatively observe the 5 major air pollutants (NO2, O3, SO2, CO and particulate matter) to determine a level of hazard. The EPA is also responsible for disseminating the findings of the Index to the public, governmental agencies, and industry/commerce. Local listings of AQI can be found at and are also often mentioned in local newspapers, television stations and radio programs.

Although air quality is routinely measured, the problem of pollution still exists. Besides the U.S. EPA, many other domestic and international organizations work tirelessly to combat pollution. Governments are increasingly investing money into research and development of cleaner fuel alternatives that have potential to drastically cut down the use of fossil fuels, one of the greatest contributors to air pollution. These alternatives, including solar and wind energy, biodiesel, etc, can be applied both on a large-scale industrial level (factories, transportation of goods, etc) as well as on an individual level (cars, home solar panels, etc). Even though the EPA is responsible for the control of air pollution, there is great value in knowing the health of the air around us, as well as understanding ways that individual citizens can help tackle the issue of air pollution. This could include such simple tasks as: riding a bike or walking instead of driving, buying from local farmers’ markets or starting a no idling campaign for buses at your school.[11]    


Below are several resources with more information specifically about the EPA, AQI and how they function.

  • AQI Brochure and Information – U.S.Environmental Protection Agency

  • Technical Assistance for Air Quality Index –U.S.Environmental Protection Agency ; page 9, 16-18



Warm-up: What is an Air Quality Index?

  1. Begin class by writing on the board: “How Healthy is the Air You Breathe?”
  2. Ask students how they would answer this question and what they took into consideration when determining their answer.
  3. Ask students to make a list of all the groups in their communities and the nation that are interested in this question. For each answer given, make sure the student supports their answer with reasons why healthy air is important to the group. Keep track of these responses on the board. Answers will include the general public, government, industry/commerce, doctors, etc..
  4. Ask students who they think should be responsible for monitoring air quality? The government is responsible for ensuring that all citizens have access to healthy air. In the U.S., the government set up the Environmental Protection Agency to monitor air quality.
  5. Ask students how they think scientists judge the health of the air? Scientists use empirical observations, such as monitoring data from the atmosphere, or public health data and trends.
  6. Introduce the idea of an Air Quality Index (AQI) as a tool used to understand the health of the air we breathe on a daily basis. The AQI monitors data that can be analyzed to help us understand the risk of certain health concerns from the air we breathe daily.

Activity One: How healthy is the air you breathe?

  1. Provide each student with a copy of Reproducible #1 – How Healthy is the Air You Breathe.  Students should fill this out during the PowerPoint presentation.
  2. Present the accompanying PowerPoint presentation: “Air Quality Index –  How Healthy is the Air You Breathe?” to students.
  3. Allow students 5 minutes at the end of the presentation to complete their worksheets.
  4. Review answers to the worksheet using Reproducible # 2– How Healthy is the Air You Breathe – Answer Key.
  5. Ask follow-up questions such as:
  6. What did you learn from this presentation that you did not know before about the air around you? Answers will vary.
  7. Do you think the EPA’s system of monitoring and assessing air quality is sufficient?  Why or why not? If not, how do you think it could be improved? Answers will vary.  Manners of improvement might include more monitoring stations, more education about what causes air pollution and why, etc.
  8. What do you think will happen in 10, 20, or 100 years if humans continue to find more ways to create air pollution?  What will our community and the world in general look like if we don’t stop driving so many cars and producing so many goods in fossil fuel burning factories?  Answers will vary.

Activity Two: Particulate Pollution Activity

  1. Explain to students that now that they have a firm grasp of the basics of air pollution, they will be moving on to study one particular type of pollution in depth: particulate pollution.  Explain that particulate pollution is a type of pollution that is made up of many tiny particles suspended in the atmosphere. These particles are sometimes too small for the naked eye to see but can be very dangerous to one’s health and the environment. An example of particulate pollution is soot from an exhaust pipe of a car. Allow time for questions on this specific type of pollution.
  2. Break students into lab partners and provide each pair with a copy of Reproducible #3 – Particulate Pollution Lab Report and the materials they will need for this activity (please see Reproducible #3 – Particulate Pollution Lab Report below.)
  3. Each group will be given 4 slides that they will leave in place in different locations around the school to collect particulate pollution for 24 hours. These 4 separate locations can be predetermined by the teacher or left open for the students to decide. Locations should, however, be diverse, such as the cafeteria, the parking lot, the classroom, the bathroom, close to the heating system, etc.
  4. Allow students five minutes with their groups to discuss where they will leave each slide. Have them record on their lab report these four locations.
  5. After reviewing Reproducible #3 – Particulate Pollution Lab Report with students and allowing time for questions, ask students to make a hypothesis about which of their chosen locations will have the most particulate pollution. Have students record their hypothesis in Reproducible #3 – Particulate Pollution Lab Report.
  6. Supervise students as they follow steps # 3 – 4 on Reproducible #3 – Particulate Pollution Lab Report.
  7. Either as a class or in lab pairs, send students to place their four slides in their chosen locations around the school. Make sure they affix their slides with tape to guarantee that they will be left undisturbed for the full 24 hour period.
  8. In class the next day, have students collect slides and complete step #8 on their lab report to begin to analyze their data.
  9. Students must complete their lab reports by creating a graph of their data, writing a conclusion and answering the lab questions. Refer to Reproducible #4 – Particulate Pollution Lab Answer Key for answers.
  10.  Display each group’s graph and observation drawings and lead a class discussion about the different results and their implications for the research question: which location had the most particulate pollution? The least? Why? How could particulate pollution be decreased in these areas? 
  11. *Optional: Provide local AQI statistics for the day of the experiment and discuss comparisons between official numbers and student data. This information will be available in your local newspaper or online.

Wrap Up: Pledge to Reduce Your Impact on Air Pollution

  1. Review all concepts from this lesson by asking students the following questions.
    1. What are the causes and effects of air pollution?  Causes include natural emissions from volcanoes, fires, dust, pollen and spores as well as man-made emissions from vehicles, factories, etc. Effects include health problems such as asthma and lung cancer, destruction of vegetation through loss of leaves, death of animals from polluted habitats, etc.
    2. How is air pollution measured? Why is it important to keep track everyday? Air pollution is measure by an AQI and is important because it can have serious health and environmental side effects.
    3. What are ways that excessive air pollution can be prevented? Less burning of fossil fuels through clean energy (bio diesel, solar, hydroelectric) and by cutting back on car use, idling, etc.
  2. Have students assess the way air pollution affects their own lives by examining pollution sources near and inside their homes as well as activities they participate in that create air pollution (driving, consuming non-local foods, etc).  Encourage them to brainstorm ways to reduce their individual air pollution contribution and create a pledge to cut out one or more of these polluters from their daily lives.

Extension One: SmogCity2

Students will extend the ideas learned in this lesson by using an interactive air pollution simulator[12] to see how individual choices, land use, and environmental factors may affect the air we breathe. The simulation may be used by individual students with computer access, small groups, or as a class.

Extension Two: Pollutants in Your Life

Divide students into five groups, with each group focusing on just one of the AQI monitored pollutants. Have each group take pictures of everyday activities (or find pictures on the Internet or in magazines) and make a poster for their assigned pollutant. What activities contribute to each pollutant?



In this lesson, students learned about the way air quality is classified and what specific factors affect the amount of particulate matter in the air.  Students should have a greater appreciation for the importance of healthy air and have brainstormed ways to decrease air pollution in their own lives and in the world at large.



Clean Air Campaign – Author

Annie Stoller-Patterson– Contributor  

            Education Intern, Earth Day Network

Maggie Ollove – Editor

            Education Associate, Earth Day Network




[2]“What is Air Pollution.” Environmental Protection Agency, Victoria, Retrieved June 2, 2011 from <>.

[3]“Air Quality Index Entry.”  Cultural Online Dictionary.  Retrieved 2 June 2011 from

[4]“Air Quality Standard Entry.”  Coalition for Clean Air Glossary.  Retrieved 2 June 2011 from

[5]“Carbon Monoxide Entry.  Merriam Webster Online Dictionary.  Retrieved 2 June 2011 from

[6]“Environmental Protection Agency Entry.”  Webster’s Online Dictionary.  Retrieved 2 June 2011 from

[7]“Ground-Level Ozone Entry.”  EPA Online.  Retrieved 7 June 2011 from

[8]“Nitrogen Dioxide Entry.”  Merriam Webster Online Dictionary.  Retrieved 2 June 2011 from

[9]“Particulate Entry.” Merriam Webster Online Dictionary.  Retrieved 2 June 2011 from <>.

[10]“Standard Entry.” Merriam Webster Online Dictionary.  Retrieved 2 June 2011 from <>..

9“Sulfur Dioxide Entry.” Merriam Webster Online Dictionary.  Retrieved 2 June 2011 from