Threats to Wilderness From Pollution
Two photos of the same landscape showing a comparison between clear blue sky and haze.
Air PollutionPollution affecting wilderness can be airborne. The Forest Service Air Resource Management Program estimates that air pollution impairs visibility to some degree on all federal lands, with visibility in the east estimated at one-third of what it would be without human caused air pollution, and visibility in the west estimated at about one-half of the visual range under natural conditions. Sources of air pollution include both primary and secondary pollutants. Primary pollutants come directly from sources such as industrial facilities, automobiles and forest fires and include sulfur and nitrogen compounds, particulate matter, and volatile organic compounds like paints and toxic metals, such as mercury. Secondary pollutants, such as ozone, are formed when primary pollutants undergo chemical reactions in the atmosphere.
Water PollutionWhen pollution is precipitated out of the atmosphere as rain or snow, it may fall in wilderness resulting in lake and stream water chemistry changes and nutrient leaching in soils. Mercury deposition, mainly due to coal combustion, has resulted in fish consumption advisories in 46 states affecting 31 National Forests, Grasslands, and Recreation Areas. According to a study of 52 sites in the west, the Mount Zirkel Wilderness was the most acidic western wilderness due to acid rain from upwind pollution sites. In parts of the central and southern Appalachian Mountains, forest streams have become so acidic they no longer support aquatic life. In some cases, management actions to reduce acidity have been implemented, such as in 1999 when helicopters delivered 140 tons of limestone sand to six locations along rivers in the St. Mary's Wilderness. Controversial solutions like these are at the heart of the wilderness restoration dilemma because they preserve naturalness at the expense of wildness.
Wildernesses near urban areas, like the Great Swamp National Wildlife Refuge Wilderness in New Jersey, are also threatened with non-point source pollution from storm water runoff, soil erosion and septic systems. Research shows that this wilderness is a sink for various pollutants that flow into the swamp from tributaries and that the swamp's natural water purifying effects have decreased, making water quality leaving the swamp poorer than that entering the swamp.
It's difficult to imagine camping "underneath the stars" without the view of the cosmos above. Increasingly, however, one must often travel to the most remote places to experience truly dark skies. A world-wide study using night-time satellite imagery found, for example, that for about 80% of the United States population the night sky brightness is even greater than that measured on nights with full moons, meaning that most Americans effectively live in perennial moonlight.
Researchers warn that without serious control of light pollution, places with truly dark nights, such as wilderness areas, will see degraded night sky quality in less than 20 years. Already, data collected by the National Park Service's Night Sky Program show that almost every national park measured exhibits some degree of light pollution. However, there is reason to be optimistic. "Unlike losing a species to extinction, topsoil to erosion, or yet-to-be explored virgin lands to development, the night sky is 100% recoverable"[8 p. 30].
Satellite imagery is used to show areas of highest light pollution, shown in white and red[6 p. 3]. The gray areas represent the propogation of light pollution.
Sound PollutionSimilar to light pollution, sound pollution (noise pollution) affects both the ecological and social aspects of wilderness. Visitors to wilderness have an expectation of seeing, hearing, and experiencing phenomena associated with a specific natural environment including sounds made by wind, birds, geysers, elk, wolves, and waterfalls, for example--not vehicles, cell phones, or aircraft. Research suggests that many human-caused noises--including airplanes, tourism helicopters, digital cameras, vehicles, and even loud groups of other people--annoy visitors seeking natural soundscapes.
Established in 2000, the National Park Service Natural Sounds Program helps parks monitor acoustics and develop acoustical baseline data for planning and reporting.
- USDA Forest Service. (n.d.b). USDA Forest Service Air Quality Monitoring Website. Retrieved on August 3, 2009.
- Sams, C. (2006). Mercury Deposition. Washington, D. C.: U.S. Department of Agriculture, Forest Service, Air Program. Retrieved on October 29, 2009.
- Turk, J. T., Taylor, H. E., Ingersoll, G. P., Tonnessen, K. A., Clow, D. W., Mast, M. A., et al. (2001). Major-Ion Chemistry of the Rocky Mountain Snowpack. Atmospheric Environment, 35, 3957–3966.
- James Madison University. (2000). St. Mary's Wilderness Liming Project. Retrieved on October 29, 2009.
- Ten Towns Great Swamp Watershed Management Committee. (2007, March 2). Great Swamp Watershed Water Quality Monitoring Report.
- Cinzano, P., Falchi, P. F., & Elvidge, C. D. (2001). The First World Atlas of the Artificial Night Sky Brightness. Monthly Notices of the Royal Astronomical Society, 328, 689–707. Retrieved on October 22, 2009.
- National Park Service Night Sky Program. (2007). NPS: Nature & Science» Air Resources Division-Natural Lightscapes. Retrieved on December 31, 2013.
- Duriscoe, D. (2001). Preserving Pristine Night Skies in National Parks and the Wilderness Ethic. George Wright Forum, 18, 30-36. Retrieved on October 22, 2009.
- Rich, C. & Longcore, T. (Eds.). (2006). Ecological Consequences of Artificial Night Lighting. Washington D.C.: Island Press.
- Fidell, S., Silvati, L., Howe, R., Pearsons, K. S., Tabachnick, B., & Knopf, R. C. (1996). Effects of Aircraft Overflights on Wilderness Recreationists. Journal of the Acoustical Society of America, 100(5), 2909-2918.
- Pilcher, E. J., Newman, P. & Manning, R. E. (2009). Understanding and Managing Experiential Aspects of Soundscapes at Muir Woods National Monument. Environmental Management, 43(3), 425-435.
- O'Brien, B. (1992). Quest for Quiet - Efforts to Reduce Noise Pollution in Wilderness Areas. Sierra, 77(July/August).
- Radle, A. L. (2007). The Effect Of Noise On Wildlife: A Literature Review. World Forum for Acoustic Ecology Online Reader.
- National Park Service Natural Sounds Program. (August 23, 2009). NPS: Explore Nature» Natural Sounds. Retrieved on December 30, 2009.