Use our air activities to find out more about air quality in your part of the Waikato region.
- Use a piece of plastic wrapping to cover a section of a clean window pane.
- Remove the wrapping a week later and compare the difference between the covered section of glass and the unprotected area.
Can you see a difference between the protected and unprotected areas? Why would the covered area of glass look cleaner? What would be making the unprotected glass dirty?
- Wrap a piece of white paper around a solid object like a ruler or pencil-box, and rub it against the outside of a window.
- Write down where you took the sample on a section of the paper.
- Now take a number of different samples around the building.
- Comparing the samples will help you to decide where most of the pollution is coming from.
- Mark lines on a piece of wax paper so the paper is divided into a number of two centimetre squares.
- Attach the paper to a piece of cardboard.
- Evenly smear the paper with vaseline.
- Place the board in an open space in the school yard where it can be left undisturbed for a week.
At the end of the week closely examine one of the squares on the board. Using a magnifying glass or microscope, can you count the different types of particles that have stuck to it? Compare your results with other squares on the sheet and with results from sheets left in different areas.
- Stretch some rubber bands over a wire coat hanger and bend the hanger until the bands are tight.
- Hang the hanger outdoors in a shady place so it’s out of the sun and leave it there for two weeks.
- When two weeks are up, look at the rubber bands. Do they look the way they did before, or are they cracked? Check with a magnifying glass too.
- Touch the rubber bands. Do they feel the way they did before, or are they hard?
If they look and feel the way they did before, then the air is quite clean. If they look cracked and feel hard, then the air is polluted.
- Fill a clear glass bowl or clear disposable cup half full with water.
- Add one teaspoon of milk and stir to mix.
- Add one teaspoon of pepper and stir.
Observe the differences between what happens with the milk and and what happens with the pepper. How long does it take for the pepper to settle to the bottom?
Read the story on particulate matter in SEEN issue no. 7 and ask before the experiment:
- What is the water in the bowl a model of? (Air)
- What kind of pollutants did the milk act like in the water? (Gases)
- What kind of pollutants did the pepper act like in the water? (Particulates)
- Would it be easier to get the milk or the pepper out of the water? (Pepper)
- Would it be easier to remove the gases or particles out of the air? (In a controlled area, particulates can be removed by filtering the air. To remove gases from the air is more difficult. Some gases can be removed by using industrial 'scrubbers'.)
Ask after the experiment:
- What is the milk and the pepper supposed to represent? (The milk represents gaseous air pollution and the pepper represents particulate air pollution).
Draw up a table of the following pollutants and classify them as a particulate, gas or both:
|car exhaust||carbon dioxide|
|carbon monoxide||cigarette smoke|
|power plants||rotting leaves|
|sand blasting||sewer gases|
Window catchers, collecting dirt and the vaseline test were all taken from publication no. 155, Environment Protection Authority, Melbourne, Australia.
The rubber band test and the particulate matter activity were taken from Internet page of the Office of Air Quality (see Useful links page for web site)