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Evidence Base Home » Parks and Open Spaces » Parks and open spaces improve environmental quality by filtering air and water and dampening noise thereby contributing to better health outcomes

Articles in Parks and open spaces improve environmental quality by filtering air and water and dampening noise, thereby contributing to better health outcomes.

  • Trees in New York City, for example, removed an estimated 1,821 metric tons of air pollution in 1994.

    US Dept of Agriculture, Forest Service pamphlet #FS-363, cited in Benefits of Trees in Urban Areas. Colorado Tree Coalition. Available at HYPERLINK "http://www.coloradotrees.org" http://www.coloradotrees.org

  • In an area with 100% tree cover (such as forest groves within parks), tress can remove as much as 15% of the ozone, 14% of the sulfur dioxide, 13% of particulate matter, 8% of the nitrogen oxide, and .05% of the carbon monoxide.

    Sherer PM. 2003. Parks for people: Why America needs more city parks and open space. San Francisco: The Trust for Public Land. Available at HYPERLINK "http://www.tpl.org/" http://www.tpl.org/.

  • Trees and the soil under them filter water pollution by removing polluted particulate matter from water before it reaches storm sewers and absorbing nutrients created by human activity such as nitrogen, phosporus and potassium, which otherwise pollute streams and lakes.

    Nowak DJ. The effects of urban trees on air quality. U.S. Dept of Agriculture Forest Service. Washington DC. Available at HYPERLINK "http://www.fs.fed.us/ne/syracuse/gif/trees/pdf"

  • Increased vegetation dampens sound and mitigates noise pollution.

    Beattie J, Kollin C, Moll G. 2000. Trees help cities meet clean water regulations. American Forests. Available at HYPERLINK "http://www.americanforests.org/downloads/graytogreen/treeshelpcities.pdf" http://www.americanforests.org/downloads/graytogreen/treeshelpcities.pdf

  • The leafy canopy of trees reduces surrounding temperatures, provides natural shade, and reduces ultraviolet radiation (UV) and the risk of skin cancer.

    Grant R, Heisler G, Gao W. Estimation of Pedestrian Level UV exposure under trees. Photochemistry and Photobiology. 2002;75(4):369-376.

  • Trees and vegetation more effectively and less expensively manage the flow of stormwater runoff than do concrete sewers and drainage ditches. Trees intercept rainfall, and unpaved areas absorb water, slowing the rate at which it reaches stormwater facilities. This alleviates pressures on storm water management and flood control efforts.

    Trust for Public Land. The Benefits of Parks: why America needs more city parks and open space. 2005.

  • In one urban park, tree cover was found to remove 48 pounds of particulates, 9 pounds nitrogen dioxide, 6 pounds sulfur dioxide, 2 pounds carbon monoxide, and 100 lbs of carbon on a daily basis.

    Coder, Dr. Kim D., “Identified Benefits of Community Trees and Forests", University of Georgia, October, 1996.

  • Trees remove gaseous air pollution primarily by uptake via leaf stomata, though some gases are removed by the plant surface.

    Nowak, David J., “Urban Trees and Air Quality.” USDA Forest Service, Syracuse, NY, November, 1995.

  • Shade from trees can reduce air temperature. Reduced air temperature due to trees can improve air quality because the emission of many pollutants and/or ozone-forming chemicals are temperature-dependent.

    Nowak, David J., “Urban Trees and Air Quality.” USDA Forest Service, Syracuse, NY, November, 1995.