Exploring Our Breathing

Materials

Estimation

How much air do you think you take in or let out in one normal-sized breath?

Procedure

1. Have one person fill the plastic gallon jug right up to the top with water. Then put the cap on the jug.

2. Another group member should fill the tub with 3-4 inches of water.

3. Have the person whose turn it is put one end of the plastic tubing into one end of the plastic straw, and tape it so the seal between the tube and the straw is airtight.

4. Have someone else turn the jug upside down into the water in the tub, and hold it in that position.

5. Someone else should take the cap off the jug, being sure not to let any air into the jug.

6. Have the person whose turn it is:

a. carefully insert the plastic tubing (with the straw at the other end) into the jug, once again, making sure that no air enters the jug. Gently push the tubing so it rises several inches into the jug.

b. take a normal-size breath (i.e. the size breath you usually take when you are at rest), and slowly exhale all of his or her breath into the straw that is attached to the tube. The exhaled air should bubble into the gallon jug and push water out of the jug and into the tub.

7. After the person has exhaled, have someone pull the tubing out of the neck of the jug. Recap the jug. When you recap the jug, be sure that you keep the opening under the water so that no extra air will get into the jug.

8. Lift the capped jug out of the tub and turn it right-side-up. Using the permanent magic marker, draw a line at the water level. Then, write the person's initials next to the line. The amount of air which ends up in the gallon jug is approximately equal to the amount of air that the person has exhaled in one breath and to the amount originally inhaled.

9. Repeat procedures 1-9 for each person in the group.

Smog Watch Index

Tropospheric Ozone Index