If you’re like me, you eat butterscotch pudding like it’s going out of style. Or, if you’re like me in a different way—and one that’s far more relevant here—you’re an allergy sufferer. I check the “Air Quality Tracker” thing on weather.com every morning so I’ll have some idea how badly I’ll be sneezing and wheezing throughout the day.
I’ve found that folks who don’t suffer from allergies rarely take note of all the often-gnarly crap that’s floating around in the air we breathe. Which I kind of get—we’re nowhere near as bad as Beijing, China, where you can almost literally cut through the air pollution with a knife. If you can’t see the particulates and junk in the air, how bad can it be?
Well, that’s where this handy dandy lil’ experiment comes in. This one will help your students get a good look at just how much pollution we breathe in every day. Come on now won’t you hey?!
DIY Pollution Catcher
For this Demo Science science demo, you’ll need one single-serving carton of milk for each student, several safety scissors, a hole punch or two, some string, and several magnifying glasses. Your students will all need at least one sheet of paper, a writing utensil, and a soupçon of petroleum jelly.
Start by having your students knock back the milk, and save the cartons. If you have any lactose-intolerant students who can’t drink the milk, they should automatically receive an F for the day, and probably for the whole class. Participation is a big part of the grade in my science classroom, Kevin’s mom!
Rinse out the empty milk cartons and have the kids cut them apart. Chop the tops right off, then cut the four sides into separate little squares. Toss the bottoms. Punch a hole in one corner of each square, and thread a length of string through each hole, tying it into a loop from which you can hang the square. Draw a 1” x 1” square in (roughly) the center of each square. These are your rudimentary pollution catchers. (If you want to supercharge the experiment, you can use those super fancy fabric filters that factories use to catch the junk floating in their air. Note that this is probably prohibitively expensive, but you can do what you want. I’m not the boss of you.)
With their pens and paper, have each students create a “data sheet” with which to record data as it becomes available. These data sheets should look something like this:
Let the Sciencing Begin
Now, your students each need to decide on four locations where they want to hang their milk carton squares for observation. Good possibilities include their back yards, off the front of their desks, in a park, etc. etc. Students can double up on locations if they want, so you don’t need to come up with dozens and dozens of different places.
Ask them where they think they’ll find the most pollutants. Will it be outside on a public street? At your school? In their homes? What’s the reasoning (if any) behind their answers?
Have the kids write the name of each location in the “Location” field of their data table. The more specific the better—if it’s at their house, write the address; if it’s at Lake George Park, write “Lake George Park”; if it’s at the corner of Heartattack and Vine, write that down. Have them write the name of the location where they will be installed on the bottom of their cardboard squares.
Here’s where Ma and Pa Student have to get involved. Send the kids home with their cardboard squares and data sheets, and ask them to have their parents help them hang their squares up in the locations they designated. Just before hanging them up, they should smear a dab of Vaseline in the boxes they drew on the squares.
Three to Five Days Later…
Send the kids out to retrieve their squares a few days later, keeping them carefully separated so the petrojel doesn’t get smudged. Have them bring the squares back to class for further study.
Pass around the magnifying glasses so your students can study the visible particles stuck in the Vaseline on their milk carton squares. Have them write the number that each one gathered in the appropriate place on their data sheets. Add up the total and calculate the average number of visible particles collected.
Which site was the most polluted? Who had the highest total number? Who had the highest average per square? What does that say about your students’ chosen locations?
Most likely, your students will discover that indoor locations generally produce just as much, if not more, visible particulate matter than outdoor ones. This is because indoor locations don’t have the same air flow as outdoor ones, and particles tend to stay in the air longer and get kicked up again and again as people pass through the area. Outdoors, the wind blow particles away and keeps the area “fresher.”