What Do Concentrations Mean

1
What Do Concentrations Mean?

• How much is 20 parts per billion?

2
How much Ozone?

• Low
• 0 to 20 ppb
• Normal
• 30-50 ppb
• High
• gt 60 ppb

3
350 ppm

• 350 molecules of carbon dioxide for every one
  million molecules of air mixture.
• Scientists would express this amount as 350
  parts per million (ppm).

4
or350 ppmv

• by Volume
• Some things are measured by mass (ppmm)
• Some gases occur in even smaller amounts.
• Ozone is measured in parts per billion (ppbv)
• Some gases are measured in parts per trillion!
  (pptv)

5
Parts per million

• 1 12 oz can of soda per 30 meter swimming pool.
• 1 3-oz chocolate bar/football field
• 1 bogey/3,500 golf tournaments

6
Parts per billion

• 1 square foot/36 square miles
• 1 bad apple/1,000,000 barrels of apples
• 1 pinch of salt/10 tons of potato chips

7
Parts per trillion

• 1 square inch/250 square miles
• 1 postage stamp/an area the size of Dallas, Texas
  
• 1 flea/360,000,000 elephants!