Noise, in the form of traffic, horns, sirens, dogs, jackhammers, and overhead jets, is a type of pollutant. National parks and other lands located in remote, unpopulated areas remind people how noisy their everyday worlds are and how precious silence is. Besides the obvious stress factor, other specific effects of noise on human beings have been well documented. Long-term exposure to high levels of noise decreases hearing ability, increases the level of cholesterol in the blood, and raises blood pressure. The impacts of noise pollution on natural resources are not well known.However, remote western parks are not immune to noise pollution. Sounds can travel great distances in the desert. A nearly constant source of noise in the backcountry of Canyonlands and many other areas is aircraft, primarily high commercial jets. Scenic flights are not as frequent, though the noise produced is usually much greater since they fly at lower elevations and frequently circle above popular sights.
Motorboat traffic on the Colorado and Green rivers is another source of noise in the backcountry of Canyonlands. In fact, the National Park Service has been trying various ways to reduce the noise created by their patrol boats, including using four-stroke outboard engines and jet drives. Although air, water and bus tours provide some visitors access to remote areas they might not otherwise see, such activities can be inconsistent with the agency's mission to preserve natural conditions. Researchers at Canyonlands monitor sound levels and intruding noises in order to establish baseline data on sound levels in the park. This information will enable the National Park Service to work more effectively with tourism and aviation interests toward preserving or restoring natural quiet in national parks nationwide.