Air pollution The Phoenix metropolitan area, like many large cities, has problems with air pollution at certain times of the year. You can do a simple experiment to determine some of the factors that affect air pollution.

• temperature
  
• wind speed
  
• barometric pressure
  
• carbon monoxide
  
• particulates
  
• sometimes ozone is also given...

Ozone, carbon monoxide, and particulates are all considered bad at high levels. Try to graph all your different measurements on the same piece of graph paper or the same computer-generated graph. You will see the effect of barometric pressure the best if you will take the nespaper reading given in inches and subtract 29 from each reading. That's because there is relatively little variability in barometric pressure when compared to the other readings.

(Thanks to Molly Roberts and Lori Birge at Lowell Elementary School in Phoenix for suggesting this experiment).