The air we breathe looks clean so we don’t usually think about the tiny things that it carries. Pollen, skin cells, bacteria and viruses, dirt, and dust can all be found in the air. In addition, air can carry soot and harmful fumes. For most people, these things aren’t a problem in small amounts, although bacteria and viruses can make us sick. Pollen, dirt and dust can be harmful to people with allergies, asthma and other breathing problems.
Microscope slides and coverslips
Use a cotton swab to coat the center of a slide in petroleum jelly. Place the slide in an area where the air moves frequently; this could be a room in your house, in your classroom, your car, or even outside. Note: if you are placing a side outdoors, make sure that it is somewhere it cannot be damaged (like getting wet or even blown away). After one or two days, retrieve your slide. Cover with a coverslip and under the microscope.
Depending on where you placed your slide, you will see different things. For example, if your slide was outdoors you may see pollen, dirt and possibly small insects. If your side was inside, you are likely to see fibers dust, hairs, and possibly skin cells. If you have a fireplace, you may also see soot. You can experiment to find the room in your house or school that has the cleanest air. You could also try to collect particulates from different places outdoors and see how they compare.