Science Activity: Measuring Air Pollution

Do you collect anything? Well, maybe you'd like to start a nice collection of dust or dirt. That's what scientists who study air pollution do everyday. In this activity, you'll study the air outdoors to learn how clean it is. You may be breathing in more than air!

1. Get Ready    

Roll of white, plastic furniture repair tape (available at a hardware store)
Two rulers, each 12 inches (about 30 centimeters) in length
Two paper cups    
Masking tape
Hand lens (magnifying glass)    
Scissors

2. Do and Wonder

Cut two strips of tape, each 5 inches (about 13 centimeters) long. Tightly wrap one end of each ruler with a strip of tape so the sticky side is facing out. Overlap the ends of the tape to hold it in place.

Place a paper cup on each taped end of each ruler, but don't touch the sides of the cup to the tape. (You're using the cups to keep particles off the tape until you put the rulers outside.)

Take the rulers outside, and decide on two locations to test. Stick each ruler in the ground, or tape it to the corner of a building. Remove the paper cups. Predict which ruler will gather the most particles.

After three days, observe the tape on each ruler. Use the hand lens to count how many particles have stuck to each tape.

3. Think and Write

Write a short paragraph that answers these questions: Did the tapes collect about the same numbers and kinds of particles? What might be the sources of the particles you observed? Where would these particles be if you had been standing where the rulers were located for the last three days?

Explanation    

The air contains tiny particles of dust, soot, and pollen, which can be seen with a hand lens. It may also contain particles of lead and mercury, which are too small to see. Some particles come from faraway volcanic eruptions and soil that has been blown into the air. Other sources are coal- and oil-powered electricity-generating plants along with factories, exhaust, and forest fires. Breathing in any of these particles can cause problems for your respiratory system.