The scenery is spectacular, but don't go for the pure mountain air. According to a recently published study, air in Washington's Mount Rainier National Park contains higher concentrations of ozone, a major component of air pollution, than nearby urban areas. This means local rural residents and park visitors, as well as the beautiful forests, wetlands and alpine meadows of the park, are being exposed to elevated levels of this pollutant, especially during those warm summer days that favor the production of ozone.

The study, by Dr. David Peterson of the USGS Forest and Rangeland Ecosystem Science Center, was published in the scientific journal "Atmospheric Environment," and adds to the growing body of evidence that protected areas such as national parks are vulnerable to pollution from outside sources. The ozone at Mt. Rainier, for example, is blown in from Seattle and other urban centers in western Washington.

Ozone is a natural component of the Earth's atmosphere, but its effects vary depending on where and in what concentration it occurs. High above the Earth's surface, in the stratosphere, a protective layer of ozone screens the earth from biologically harmful frequencies of ultraviolet radiation. The stratospheric ozone layer is essential to the existence of many forms of life.

However in the lower part of the atmosphere, called the troposphere, human-produced ozone can be a dangerous pollutant. The colorless gas is formed from byproducts released during the burning of fossil fuels, and can be toxic to both plants and animals, including humans, even at fairly low concentrations.

"It's well documented that both periodic episodes of high ozone exposure and chronic moderate ozone exposure can be harmful to plants," said Peterson. "We know this from other regions of North America including national parks such as Sequoia and Great Smoky Mountains."

Sources of ozone-producing compounds, including automobile exhaust and fuel-burning ind
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Contact: Ruth Jacobs
ruth_jacobs@usgs.gov
541-750-7304
United States Geological Survey
28-May-1999