Exploring Air Pollution Causes: Grades 4-8
The Georgia-based Clean Air Campaign recently rolled out its new Better Air Schools initiative to 20 Atlanta-area schools. The initiative includes a science curriculum on air pollution that's available for freee download in .pdf format at http://www.cleanaircampaign.com. For more details, turn to this month's Q&A on p. 14. Here's an excerpt from a lesson aimed at 4th-grade classrooms about how haze is formed, its impact on human health and what can be done to reduce it: www.curriculumreview, com
Darken the classroom. Gently throw a handful of flour into the air, being careful to keep far enough away from the students. Shine a flashlight on the falling flour and ask students to describe what they see. Discuss how the flour floats in the air, separating into tiny pieces--like dust. Tell students that these tiny pieces are called "particles."
Explain that many different kinds of particles float in the air and can be inhaled into the lungs, making people cough; indicate that this experiment was done far away from the students so that they would not breathe in the flour.
Turn the lights back on. Blow air into a plastic sandwich bag and seal. Hold up for students to see, and then circulate to show all of the students. Ask what is in there (likely response will be "air"), then ask if they think there are particles of anything in there.
Explain that while the flour particles could be seen by our eyes, there are many, many particles in the air that cannot be seen. Ask a student to draw a circle on the board and tell students to pretend that the circle is a strand of hair cut open--a "cross section," have the student label the diameter "70 microns." Then ask two other students to draw two tiny circles inside the large circle and have them label their diameters "2.5 microns."
Explain that microns are very, very small units of measurement. Indicate that particles in the air can be that teeny tiny--we can't see them, but they are still there. When they mix with liquid droplets in the air, scientists call them a fancy name: particulate matter, or I'M. Explain that scientists have found that when there are high amounts of particulate matter the air can look hazy--and people, especially those with sensitive lungs, can get sick. Tell them that they're going to find out how that happens through the Cilia (not silly!) Game.
In an open area, designate a trapezoid shape with four orange traffic/sports cones (Teacher background information on the role of cilia in the respiratory system can be found at http://kidshealth.org/teen/your_body/body_basics/lungs. …