20-Second Smells

In this lesson, students learn that we often encounter odor fatigue, i.e., we become accustomed to the smells around us after about 20 seconds of exposure, even when those smells are unpleasant or toxic. Students enjoy investigating different smells, and then engage in a thought-provoking discussion about how many smells that are familiar and may even be pleasant to us are actually toxic. They think about ways to “reset” their nose to do a better job of detecting indoor air pollution and brainstorm things they can do to reduce the number of indoor air pollutants at their homes.