Pollution Patrol

This lesson focuses on devices that are used to detect air pollution. Teams of students construct outdoor air pollution detectors from everyday materials. They then test their devices to see how much particulate pollutants they can capture.

Students will:

Design and build an outdoor air pollution detector
Test and refine their designs
Communicate their design process and results

Age Levels: 8-18

Materials & Preparation

Build Materials (For each team)

Required Materials

Construction paper
Cardboard
Plastic wrap
Wax paper
Fabric
String or yarn
Felt
Coffee filters
Index cards
Paper plates
Paper cups
Double-sided tape
Petroleum jelly
Karo syrup
Hangers

Testing Materials

Hand lens
Graph paper
String
Optional: Microscope or digital camera

Testing Materials & Process

Materials

Hand lens
Graph paper
String
Optional: Microscope or digital camera

Process

Each team tests their air pollution detector by placing it at a different location around the school. After 72 hours, they should check to see whether their tester collected any particles. They should use a hand lens, microscope, or digital camera to examine the particles collected.

Teams should document the different types of particles they see (e.g. dust, pollen, dirt etc), as well as their size, color, shape and texture. Then, they should use string to create a grid of 1cm squares over their device’s collection area, securing it with tape.

Next, instruct students to count the number of particles in five random squares. If there are too many to count, estimate. Calculate the average number of particles per square. Compare and graph the findings for the different locations tested in the class. Develop a scale to rate air quality/air pollution at the locations tested around your school.

Engineering Design Challenge

Design Challenge

You are a team of engineers who have been given the challenge to design a device that can detect the presence of particulate pollutants outside of your school. The device must have a flat collection area which is at least 5cm x 5cm. The device needs to have relative protection from the elements and should be able to be secured (so it doesn’t blow away).

Criteria

Must have a flat collection area which is at least 5cm x 5cm.
Must be able to secure it.

Constraints

Use only the materials provided.
Teams may trade unlimited materials.

Activity Instructions & Procedures

Break class into teams of 2-3.
Hand out the Pollution Patrol worksheet, as well as some sheets of paper for sketching designs.
Discuss the topics in the Background Concepts Section. Ask students to share some sources of air pollution, how they think it is measured and how it impacts society. Discuss how engineers design instruments that can detect the presence of different types of pollutants in the air.
Review the Engineering Design Process, Design Challenge, Criteria, Constraints and Materials.
Provide each team with their materials.
Explain that students must design a particulate air pollution detection device. It must have a flat collection area that is at least 5 cm x 5 cm. The device should have relative protection from the elements and should have a way to be secured.
Announce the amount of time they have to design and build (1 hour recommended).
Use a timer or an on-line stopwatch (count down feature) to ensure you keep on time. (www.online-stopwatch.com/full-screen-stopwatch). Give students regular “time checks” so they stay on task. If they are struggling, ask questions that will lead them to a solution quicker.
Students meet and develop a plan for their air pollution detection device. They agree on materials they will need, write/draw their plan, and present their plan to the class. Teams may trade unlimited materials with other teams to develop their ideal parts list.
Teams build their designs.
Each team tests their air pollution detector by placing it at a different location around the school. After 72 hours, they should check to see whether their tester collected any particles. They should use a hand lens, microscope, or digital camera to examine the particles collected.

As a class, discuss the student reflection questions.
For more content on the topic, see the “Digging Deeper” section.

Student Reflection (engineering notebook)

Did you succeed in creating an air pollution detector that could detect the presence of particles in the air? If not, why did it fail?
Did you decide to revise your original design or request additional materials while in the construction phase? Why?
Did you negotiate any material trades with other teams? How did that process work for you?
If you could have had access to materials that were different than those provided, what would your team have requested? Why?
Do you think that engineers have to adapt their original plans during the construction of systems or products? Why might they?
If you had to do it all over again, how would your planned design change? Why?
What designs/methods did you see other teams try that you thought worked well?
Do you think you would have been able to complete this project easier if you were working alone? Explain…
What type of particulate pollution did you find the largest quantity of? Why do you think that is?
What do you think can be done to reduce particulate pollution around your school?

Time Modification

The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.

Engineering Design Process

Background Concepts

Air Pollution

Air is essential to life. The air around us is comprised primarily of the elements nitrogen and oxygen. When other substances such as chemicals, natural materials, or particles enter the air, this is known as air pollution. Air pollution can occur both indoors as well as outdoors. It can have both natural and human induced causes. Air pollution impacts humans, animals and the environment in a number of different ways.

Air pollution can be the result of a number of different types of human activity. When pollutants from smokestacks and automobile emissions are released into the air, chemical reactions occur in the atmosphere which can lead to a number of problems. Smog occurs when pollutants in the air mix with ozone, causing hazy atmospheric conditions and respiratory problems in humans. Smog typically occurs over large cities or industrial areas. London, Los Angeles, Mexico City and Southeast Asia all have significant problems with smog. Acid rain occurs when pollutants such as sulfuric acid mix with water in the air, causing rain and snow to become too acidic. This acidity is very harmful to the environment and as a result kills plants, trees, fishes and animals. When fuels are burned for energy in automobiles, factories, fireplaces and barbecues, tiny particles are released into the air. These particles make up what is known as particulate matter pollution.

Particulate Matter

Pollution caused by particles, also known as particulate matter, consists of a mixture of small particles and liquid droplets in the air. Particulate matter can include both coarse particles and fine particles. Coarse particles are larger than 2.5 microns but less than 10 microns in diameter (A human hair is roughly 70 microns in diameter). These can include smoke, dust, dirt mold and pollen. Fine particles are less than 2.5 microns in diameter. Fine particles can include toxic compounds and heavy metals.

Particulate pollution, particularly fine particle pollution, is very harmful to humans when inhaled. Particulate matter disrupts ecosystems. Particles in the air also cause hazy atmospheric conditions. The amount of particulate matter in the air varies depending on the time of the year and the weather. For example, the amount of particulate matter may be higher in the winter due to an increase in the use of fireplaces and wood burning stoves. Particulate pollution is also categorized by its source. Primary particles can be traced directly to their sources, such as smokestacks, idling vehicles or power plants. Secondary particles on the other hand, are created through reactions in the atmosphere and are therefore much more difficult to trace.

Particle Matter Samplers and Counters

Particulate matter samplers collect particulate matter to determine how much is in the air and so that particles may be examined later in a laboratory. One type of particulate matter sampler draws air through a filter attached to a glass tube. The weight of the filter is taken before the sampling occurs. After the filter has collected some particles, it is then weighed again. The amount of particulate matter is calculated using the weight of the particulate matter collected by the filter and the amount of air sampled. Another type of particulate matter sampler collects particulate matter on a reel of filter tape, which is weighed before and after the sampling.

Instruments known as particle counters detect and count the number of particles in the air. Aerosol particle counters count the number of particles in the air and measure their size. Light blocking particle counters detect the amount of particles in the air by passing light through an air sample and measuring how much of that light is being blocked by the particles. This method can be used to assess particles that are larger than 1 micrometer. Smaller particles (larger than .05 micrometer) can be detecting using the light scattering method. This method measures how much light is scattered by particles in an air sample. Lasers can also be used to illuminate an air sample so the silhouettes of particulate matter can be captured with a digital camera for magnification and examination.

Rating Air Quality

The World Health Organization has established guidelines for air quality based on the negative health effects of pollution on humans. Many countries have established scales that rate the quality of the air in a particular region at a given time. These scales rate air quality based on the concentration of pollutants in the air, but vary by location and also as to which type of pollution they assess. Despite evidence of the negative impact of air pollution on health, many countries still do not monitor and rate air quality.

In Mexico City, the Sistema de Monitoreo Atmosférico de la Ciudad de México (SIMAT) uses a rating system known as Índice Metropolitano de la Calidad del Aire (IMECA) to measure concentrations of pollutants including fine particulate matter, carbon monoxide, sulphur dioxide, nitrogen dioxide and ozone. A 200 point rating scale consisting of five categories ranging from “buena” (good) to “extremadamente mala” (extremely bad) is used to rate and describe air quality conditions. In the United States, the Environmental Protection Agency uses the Air Quality Index which examines concentrations of these same pollutants and assigns a rating on a scale of 0 to 500. Within this scale there are six categories that describe the quality of the air ranging from “Good” to “Hazardous”. The Hong Kong Environmental Protection Department also rates air pollution on a 500 point scale with five categories ranging from “low” to “severe” based on concentrations of pollutants in the air. In March 2010, Hong Kong’s air pollution hit record levels (over 500!) after a serious sandstorm occurred in southern China.

Vocabulary

Aerosol Particle Counter: Count the number of particles in the air and measure their size
Air Quality: A measure of how clean or polluted the air is.
Constraints: Limitations with material, time, size of team, etc.
Criteria: Conditions that the design must satisfy like its overall size, etc.
Engineers: Inventors and problem-solvers of the world. Twenty-five major specialties are recognized in engineering (see infographic).
Engineering Design Process: Process engineers use to solve problems.
Engineering Habits of Mind (EHM): Six unique ways that engineers think.
Iteration: Test & redesign is one iteration. Repeat (multiple iterations).
Light Blocking Particle Counters: Detect the amount of particles in the air by passing light through an air sample and measuring how much of that light is being blocked by the particles.
Light Scattering Method: Measures how much light is scattered by particles in an air sample.
Particle Counters: Detects and counts the number of particles in the air.
Particulate Matter Sampler: Collect particulate matter to determine how much is in the air and so that particles may be examined later in a laboratory.
Pollution: A contaminated environment or dirtied by waste, chemicals, and other harmful substances. There are three main forms of pollution: air, water, and land.
Prototype: A working model of the solution to be tested.

Dig Deeper

Internet Connections

Recommended Reading

Air Pollution. (ISBN: 9780761432203)
Air Pollution: Measurement, Modelling and Mitigation (ISBN: 978-0415479325)

Writing Activity

Write a letter to your local politician about ways air pollution can be reduced in your community.

Curriculum Alignment

Alignment to Curriculum Frameworks

Note: Lesson plans in this series are aligned to one or more of the following sets of standards:

U.S. Science Education Standards (http://www.nap.edu/catalog.php?record_id=4962)
U.S. Next Generation Science Standards (http://www.nextgenscience.org/)
International Technology Education Association’s Standards for Technological Literacy (http://www.iteea.org/TAA/PDFs/xstnd.pdf)
U.S. National Council of Teachers of Mathematics’ Principles and Standards for School Mathematics (http://www.nctm.org/standards/content.aspx?id=16909)
U.S. Common Core State Standards for Mathematics (http://www.corestandards.org/Math)
Computer Science Teachers Association K-12 Computer Science Standards (http://csta.acm.org/Curriculum/sub/K12Standards.html)

National Science Education Standards Grades K-4 (ages 4 – 9)

CONTENT STANDARD A: Science as Inquiry

As a result of the activities, all students should develop

Abilities necessary to do scientific inquiry

CONTENT STANDARD D: Earth and Space Science

As a result of the activities, all students should develop an understanding of

Changes in the earth and sky

CONTENT STANDARD E: Science and Technology

As a result of the activities, all students should develop

Abilities of technological design
Understanding about science and technology

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of the activities, all students should develop an understanding of

Personal health
Changes in environments
Science and technology in local challenges

National Science Education Standards Grades 5-8 (ages 10 – 14)

CONTENT STANDARD A: Science as Inquiry

As a result of the activities, all students should develop

Abilities necessary to do scientific inquiry

CONTENT STANDARD E: Science and Technology

As a result of the activities, all students should develop

Abilities of technological design
Understanding about science and technology

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of the activities, all students should develop an understanding of

Personal health
Populations, resources and environments
Science and technology in society

National Science Education Standards Grades 9-12 (ages 14-18)

CONTENT STANDARD A: Science as Inquiry

As a result of the activities, all students should develop

Abilities necessary to do scientific inquiry

National Science Education Standards Grades 9-12 (ages 14-18)

CONTENT STANDARD E: Science and Technology

As a result of the activities, all students should develop

Abilities of technological design
Understanding about science and technology

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of the activities, students should develop an understanding of

Personal and community health
Environmental quality
Natural and human-induced hazards
Science and technology in local, national, and global challenges

Next Generation Science Standards Grades 3-5 (Ages 8-11)

Earth and Human Activity

Students who demonstrate understanding can:

4-ESS3-2. Generate and compare multiple solutions to reduce the impacts of natural Earth processes on humans.

Engineering Design

Students who demonstrate understanding can:

3-5-ETS1-1.Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
3-5-ETS1-2.Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
3-5-ETS1-3.Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

Next Generation Science Standards Grades 6-8 (Ages 11-14)

Earth and Human Activity

Students who demonstrate understanding can:

Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.

Engineering Design

Students who demonstrate understanding can:

MS-ETS1-1 Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
MS-ETS1-2 Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

Next Generation Science Standards – Grades 9-12 (Ages 14-18)

Engineering Design

Students who demonstrate understanding can:

HS-ETS1-2.Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.

Principles and Standards for School Mathematics

Number and Operations Standard

Instructional programs from prekindergarten through grade 12 should enable all students to:
Compute fluently and make reasonable estimates

Measurement Standard

Instructional programs from prekindergarten through grade 12 should enable all students to:
Apply appropriate techniques, tools, and formulas to determine measurements.

Data Analysis and Probability Standard

Instructional programs from prekindergarten through grade 12 should enable all students to:
Formulate questions that can be addressed with data and collect, organize, and display relevant data to answer them
Select and use appropriate statistical methods to analyze data
Develop and evaluate inferences and predictions that are based on data

Process Standard (Representation)

Instructional programs from prekindergarten through grade 12 should enable all students to:
Create and use representations to organize, record, and communicate mathematical ideas
Use representations to model and interpret physical, social, and mathematical phenomena

Common Core State Standards for School Mathematics Grades 2-8 (ages 7-14)

Measurement and data

Measure and estimate lengths in standard units.
CCSS.Math.Content.2.MD.A.1 Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
CCSS.Math.Content.2.MD.A.3 Estimate lengths using units of inches, feet, centimeters, and meters.

Common Core State Standards for School Mathematics: Content (ages 7-10)

Statistics & Probability

Use random sampling to draw inferences about a population.
CCSS.Math.Content.7.SP.A.2 Use data from a random sample to draw inferences about a population with an unknown characteristic of interest. Generate multiple samples (or simulated samples) of the same size to gauge the variation in estimates or predictions.

Standards for Technological Literacy – All Ages

Design

Standard 8: Students will develop an understanding of the attributes of design.
Standard 9: Students will develop an understanding of engineering design.
Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving.

Student Worksheet

You are a team of engineers who have been given the challenge to design a device that can detect the presence of particulate pollutants outside of your school. The device must have a flat collection area which is at least 5 cm x 5 cm. The device needs to have relative protection from the elements and should be able to be secured (so it does not blow away).

Planning Stage

Meet as a team and discuss the problem you need to solve. Then develop and agree on a design for your air pollution detector. You’ll need to determine what materials you want to use.

Draw your design in the box below, and be sure to indicate the description and number of parts you plan to use. Present your design to the class.

You may choose to revise your teams’ plan after you receive feedback from class.

Design: Materials Needed:

Construction Phase

Build your air pollution detector. During construction you may decide you need additional materials or that your design needs to change. This is ok – just make a new sketch and revise your materials list.

Testing Phase

Each team will test their air pollution detector by placing it at a different location around their school. After 72 hours, check to see whether your tester collected any particles. Use a hand lens, microscope, or digital camera to examine the particles collected. Document the different types of particles you see (e.g. dust, pollen, dirt etc) as well as their size, color, shape and texture.

Use string to create a grid of 1 cm squares over your device’s collection area, securing it with tape. Count the number of particles in five random squares. If there are too many to count, estimate. Calculate the average number of particles per square. Compare and graph the findings for the different locations tested in the class. Develop a scale to rate air quality/air pollution at the locations tested around your school.

Evaluation Phase

Evaluate your teams’ results, complete the evaluation worksheet, and present your findings to the class.

Use this worksheet to evaluate your team’s results in the “Pollution Patrol” Lesson:

1. Did you succeed in creating an air pollution detector that could detect the presence of particles in the air? If not, why did it fail?

2. Did you decide to revise your original design or request additional materials while in the construction phase? Why?

3. Did you negotiate any material trades with other teams? How did that process work for you?

4. If you could have had access to materials that were different than those provided, what would your team have requested? Why?

5. Do you think that engineers have to adapt their original plans during the construction of systems or products? Why might they?

6. If you had to do it all over again, how would your planned design change? Why?

7. What designs/methods did you see other teams try that you thought worked well?

8. Do you think you would have been able to complete this project easier if you were working alone? Explain…

9. What type of particulate pollution did you find the largest quantity of? Why do you think that is?