Millenium Park, Chicago, IL. Credit: Dawn Zarimba, Flickr

Clean air is important for all life on earth. Air pollution has been related to a range of adverse health and environmental effects such as respiratory infections and acid rain. Trees absorb CO2 through photosynthesis to produce oxygen for us to breathe, and intercept air borne particles on leaf surfaces. They also play a critical role in capturing the six common air pollutants and toxic gases: ground-level ozone, particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide and lead. These pollutants come from dust, pollen, ash, motor vehicles, power plants and other industrial sources. By planting trees and restoring forests we can help minimize the problem of air pollution.


Did you know?

  • A single tree can absorb 10 pounds of air pollutants per year.[1]
  • The average healthy, mature tree produces roughly 260 pounds of oxygen annually. The average person consumes 386 pounds of oxygen per year. Two trees provide enough oxygen for one person per year.[2]
  • Chicago‚Äôs urban forest (more than 3.5 million trees) removes about 888 tons of air pollution per year.[3]



[1] U.S. Forest Service. Pacific Southwest Research Station. Urban Ecosystem and Social Dynamics. Urban Ecosystems and Processes. March 2001. (accessed June 3, 2013).

[2] U.S. Forest Service. Pacific Southwest Research Station. Publications and Products. General Technical Report. (accessed June 3, 2013).

[3] City of Chicago. Press Releases. City to Plant 3,800 Trees in Neighborhoods Across Chicago in 2013. (accessed June 7, 2013).