Now that your girls have researched some of the problems caused by air pollution, it time to get them focused on a solution. One of the easiest places to start is their own homes. First, have each girl test the air quality in their home by using poster board squares smeared with petroleum jelly placed in several places in the home. Let them sit for a week, and then use a magnifying glass to count the particles that have accumulated on the square to get a good idea of the level of particulate matter.
Have the girls brainstorm ways to improve their own indoor air quality and create a checklist that they can use to implement the changes. Some ideas are: keep floors clean; vacuum often and use a vacuum with a HEPA filter; mop after vacuuming to keep down dust and leave shoes at the front door; keep humidity at 30-50% to keep down mold and dust allergens; and make the home a no-smoking zone. The girls can use these ideas, or ones they have come up with.
Do a re-test of the home in two weeks. Set out the poster board squares with petroleum jelly and let sit for a week then recount the particulate matter. Have the girls record and discuss their observations.