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Decide where you want to test for air pollution. Choose a variety of sites, including some you think are pretty clean (for example, your room, your yard, a park), some you think are dirty (near a highway), and some in between (a downtown street).
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Smear the outside of one of the glasses with petroleum jelly and examine it with your magnifying glass. In your notebook, write down what you see. You need to know what a clean glass looks like so that you can compare your findings with it later.
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Put the glass at your first test spot. Label it with a piece of masking tape stuck to the inside. Cover the glass with a can. The can will keep out most dust from the ground that would confuse the results. Now you have your first detector.
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Make the rest of your detectors and put them at your test sites. Be sure to label each detector with the name of the site. Try to find spots where they'll be protected from rain. (Rain would wash away the evidence.)
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Check the detectors every day for a week and record any changes in the your notebook.
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Collect the detectors at the end of the week and examine them carefully with your magnifying glass. Do you see much difference between the glasses? Have you caught any strange-looking particles, or specks? Are there any surprises?
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Here's rough pollution Guide: Mark a 0.5-cm (1/4 inch) square on each collector and count the number of particles you see. If there are around 15, the site is probably fairly clean. But if there are 100 or more, try not to breathe too deeply in that area!
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For a permanent record, collect 2 or 3 leaves from each test site in
labeled plastic bags. At home, press a strip of clear tape against each
leaf on both the top and underneath sides. Any particles will stick to the tape.
Remove the pieces of tape, put them in your notebook, and label them with the site names.
Do you notice any differences between these results and those from the glass detectors?
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