Air Quality - Lesson 5: How Can We Tell What the Quality of the Air Is Today?

1. Introduce the Air Quality Index (AQI).

What do the colors in a stop light mean for people’s behavior? [Red means stop, yellow means caution, and green means go.] Tell students that they will be learning about the air quality index, which also uses colors.

Using different colors of construction paper to represent the AQI colors as presented in the teacher background material, have students rank the colors from good to poor air quality. Have students read the information from the Michigan Department of Environmental Quality and the Department of Community Health on The Air Quality Index. 

Explain that the AQI itself is not an air quality standard. Also stress that when two or more criteria pollutants are monitored at one location, the highest value (worst air measured) drives the AQI value. High AQI values in summer are often from ozone and high AQI levels in winter are from particle pollution.

Optional: The Interpreting the AQI student activity page can be used to practice AQI interpretation.

2. Find air quality information on the MDEQ and EPA web sites.

What is your local AQI and how does it compare to other sites in Michigan and the United States?

Use the What Is Your AQI? student pages to find the daily AQI, the AQI for ozone (only between May and September), and the AQI for particle pollution (year around).

Explore actual particle pollution and ozone episodes by graphing hourly values on the Patterns of Particle Pollution and Ozone student activity page either through AIRNow animated maps or using actual values. Information about what was actually happening in these episodes is found in the teacher resource on the Particle Episode, January 31-February 6, 2005 and the Case Study of the June 22-28 PM25 and Ozone Episodes in the Midwest and the United States found on the MEECS Air Quality CD.

Non-Internet based option for students:

Prior to class, check the MDEQ and EPA web sites for the latest AQI readings and provide the information to the students.

The data shown on the Patterns of Particle Pollution and Ozone student data sheet can be used to generate the time series chart without using the computer.

3. Test a hypothesis about the AQI using web

sites (Lesson Extension).

Is the Air Quality Index (AQI) the same throughout Michigan? Does the AQI change with time? With the types of pollutants

measured? Are ozone levels higher in the Upper Peninsula than in lower Michigan? Use the Tracking the AQI student activity pages

to answer questions such as these using the scientific method. Help students formulate a question concerning air quality in Michigan.

Next help them develop a reasonable hypothesis that can be tested using information from the MDEQ web site. Encourage students to find data

that are relevant to their question so that they have a solid basis for their conclusions.

Non-Internet based option for students:

Materials on the MEECS Air Quality CD include archived ozone and particle

pollution maps, air quality forecasts, and forecast maps that could be reproduced in alternate forms.

4. Explore the relationship between the AQI and weather using web sites or newspapers (Lesson Extension).

Is the Air Quality Index (AQI) related to weather conditions? Brainstorm ways that the weather

conditions might affect air quality and list them on the board and on the student activity page, The AQI and Weather. In small groups have

the students construct a reasonable hypothesis concerning weather and the AQI. Guide the students to testable hypotheses based on the data

available at the DEQ web site.

Students collect information from the weather forecast to predict the AQI for the next day.

For ozone formation, some important weather factors are amount of sunlight, wind speed and direction, and temperature. Consult actual daily

forecasts for the AQI by MDEQ meteorologists at the MDEQ web site. These can be compared to student forecasts. Finally, confirm the actual

AQI from the MDEQ web site. Have students present the results of their research to the class.

Non-Internet based option for students:

Use the data from Weather Conditions,and the Air Quality Index (AQI) for an Ozone Episode student resource as a basis for hypothesis testing. Some

newspapers carry a weather forecast with a corresponding AQI and UV index.

5. Determine the UV Index and its importance (Optional).

What is the UV Index? Now that the AQI has been explored, students can be introduced to the UV index. Have them read The Ozone

Layer and the UV Index and show them the UV Index PowerPoint slides on the Air Quality CD. Guide a discussion to reinforce the link between

stratospheric ozone depletion and UV radiation.

Why is the UV Index important? Brainstorm answers to this question and record them on the student pages, Tracking the UV Index. Use the

Internet site,, to access data for your zip code. Record daily UV Index numbers and data for one week.

If you are able, note changes in the UV Index throughout the week and as weather conditions change. Discuss reasons for these changes and

how they affect exposure to UV radiation.

Optional: Interpreting the UV Index student activity page can be used to practice UV Index interpretation.

6. Tying it all together.

Why is knowing about air quality important? Draw on the students’ knowledge about pollutants and health effects. Show the

PowerPoint on Air Pollution—Michigan on the MEECS Air Quality CD as a review of the lesson and material covered in the unit so far.

Return to the demonstration using different colors of construction paper and solicit ideas about what these colors mean in terms of AQI

levels and health.

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