Visual pollution is an aesthetic issue, referring to the impacts of pollution that impair one's ability to enjoy a vista or view. The term is used broadly to cover visibility, limits on the ability to view distant objects, as well as the more subjective issue of visual clutter, structures that intrude upon otherwise "pretty" scenes, as well as graffiti and other visual defacement.
Visibility is a measure of how far and how well people can see into the distance. Haze obscures visibility. It is caused when light is absorbed or scattered by pollution particles such as sulfates, nitrates, organic carbon compounds, soot, and soil dust. Nitrogen dioxide and other pollution gases also contribute to haze. Haze increases with summer humidity because sulfate and other particles absorb moisture and increase in size. The larger the particles, the more light they scatter.
Haze is most dramatically seen as a brownish-grey cloud hovering over cities, but it also obscures many beautiful vistas in U.S. national parks. At Acadia National Park in Maine, visual range on a clear day can be 199 miles. On a hazy day, that can be reduced to 30 miles. At its worst, haze at Grand Canyon National Park was so severe that people could not see across the 10-mile wide canyon. An enormous coal-fired electric plant, the Navajo Power Generating Station, about 80 miles north of the Grand Canyon, was thought to be the source of the pollution causing canyon haze. In 1985 researchers at Colorado State University injected methane-containing deuterium into the power plant's smoke emissions. Deuterium is not normally present in the air. When monitors determined the presence of deuterium in canyon air, researchers were able to demonstrate that the plant was responsible for much of the canyon haze. The result was a landmark settlement in which Navajo's owners agreed to a 90-percent cutback in sulfur dioxide emissions by 1999.
Utility boilers and vehicular emissions are both major sources of haze-causing pollution. The haze problem is greatest on the east coast of the United States because of the higher levels of pollution and humidity in that region. The pollution that causes haze can travel thousands of miles, and improving regional visibility requires interstate cooperation. Wood smoke is a contributor in the west, and forest fire smoke and windblown dust are natural sources of haze.
The pollutants that cause haze are also a health concern because they often result in respiratory problems among humans and other species. Controls designed to reduce the pollution from vehicular and smokestack emissions will also reduce visual pollution. In addition, the U.S. Environmental Protection Agency (EPA) has issued regional haze regulations that call on
In Southeast Asia, haze caused by massive forest fires cost billions of dollars in health care and lost tourist revenue in the last decade. Fires in Sumatra and Borneo affected not only Indonesia, but also Malaysia, Singapore, and Thailand. Most fires were set deliberately, and often illegally, to clear land for planting and development and to cover up illegal logging. Some of the fires spread to peat deposits beneath the forest, and these may continue to burn for years.
Visual blight—billboards, power lines, cell towers, even ugly buildings—is literally in the eye of the beholder. It is subjective. To the businessman, a well-placed billboard may be a thing of beauty. But to the traveler whose view of the rolling hills or the rustic village is obstructed, it is visual pollution.
Billboards proliferated in the 1940s and 1950s, spurred by the growth of automobile traffic and construction of interstate highway system, but in 1965 Lady Bird Johnson, wife of President Lyndon Johnson, attacked their growing presence on our nation's roadways. "Ugliness is so grim," the first lady proclaimed, and she fought for and won passage of the Highway Beautification Act of 1965. This groundbreaking law prompted a number of states, including Alaska, Hawaii, Maine and Vermont, to ban billboards totally; there were loopholes, however.
Sensitivity to visual pollution has led utility companies to bury power and telephone lines in some communities. The latest fight against visual pollution centers on cell towers, needed to provide cellular telephone service. One solution has been to disguise cell towers as trees or cacti. Graffiti, spray-painted
Gudis, Catherine (2003). Buyways: Automobility, Billboards and the American Cultural Landscape. New York: Routledge.
National Research Council Board on Environmental Studies and Toxicology. (1991). Haze in the Grand Canyon: An Evaluation of the Winter Haze Intensive Tracer Experiment. Washington, D.C.: National Academy Press.
National Research Council Environment and Resources Commission on Geosciences. (1993). Protecting Visibility in National Parks and Wilderness Areas. Washington, D.C.: National Academy Press.
Malm, William (National Park Service and Colorado State Institute for Research on the Atmosphere). "Introduction to Visibility." Available from http://www.epa.gov/oar/visibility .
Scenic America Web site. Available from http://www.scenic.org/billboards.htm .
Richard M. Stapleton