Grades: 3 - 4
Purpose: To identify suspended particles in air and "see" what is in the air we breathe
- white index card
- petroleum jelly
- magnifying glass or dissecting microscope
preparation - 15 - 20 minutes
15 minute observation after one week
20 minute observation/documentation after two weeks
Label a white index card with the student's name and date. Rub petroleum jelly on the other side of the card. Hang the card outside where it won't get wet if it rains (think of a place where you are likely to encounter air pollution: under a playground shelter, at a bus stop shelter, in a telephone booth, on your porch, or in a tree house). Check the card after a week, and make observations about its appearance. Remove the card after two weeks, and compare it to a clean index card. Use a magnifying glass or dissecting microscope to observe the pollution stuck on the card. Ask the students to discuss what caused the air pollution. Discuss how cards from different locations contain different pollutants. Remind them that many pollutants are so small that they can only be seen with a very powerful microscope. Prepare a school bulletin to share pollution observations.
Expected results and the reasons they occur:
Quite a bit of particulate air pollution, such as dirt and pieces of feathers, paper, straw, plastic, etc., should stick to the petroleum jelly on the cards.
Activities adapted from the Puget Sound Air Pollution Control Agency's "Clean Air Express," and from "Where's the Air," Wisconsin Department of Natural Resources.