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Air Pollutants of Concern

Photograph of students listening to a NPS air resources division presentor during a field trip to Rocky Mountain NP, Colorado
Students learn about air pollution impacts during a field trip to Rocky Mountain NP, Colorado

Air pollutants that can harm sensitive resources in National Park Service (NPS) areas include ground-level ozone, fine particles, sulfate, nitrate, ammonia, heavy metals (for example, mercury), and toxic organic compounds.

The Environmental Protection Agency has set National Ambient Air Quality Standards for several pollutants in order to protect public health and the environment. These include fine particles, sulfur dioxide, nitrogen oxides, ground-level ozone, carbon monoxide, and lead.

Air pollutants of concern to the NPS can have serious effects on air quality, human health, wildlife, vegetation, lakes, streams, soils, and visibility in NPS areas. Namely:

  • Ground-level ozone and particulate matter can cause inflammation and irritation of the respiratory system in humans. Mercury and toxic organics (e.g., pesticides, dioxins, PCBs) can affect the reproductive health of both wildlife and humans.  more »
  • Ground-level ozone can damage plant tissues and reduce growth in some sensitive plant species. more »
  • Fine particles, sulfates, nitrates, and ammonium contribute to haze and affect visibility to some degree in every national park. more »
  • Sulfur and nitrogen compounds can cause significant ecosystem effects such as acidification, excess fertilization (eutrophication), and changes in soil and water chemistry when atmospherically deposited in parks. more »
  • Mercury exposure at high levels can harm ecosystem processes. more »

Many NPS areas participate in ozone and particulate matter health advisory programs, conduct air quality monitoring programs, and support special studies that help increase understanding about the impacts of pollution in National Parks.

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Last Updated: January 10, 2013