Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: MONDAY, April 19, 1993 TAG: 9304190244
SECTION: EDITORIAL PAGE: A-5 EDITION: METRO
SOURCE: ROBERT A. DUCE
DATELINE: LENGTH: Medium
Air pollution at our national parks is not a new problem. In 1977, Congress set a goal of understanding and reducing haze caused by human activities in these areas. But after 15 years, the federal government has succeeded only in reducing the rate of growth in haze at our national parks.
For the past two years, I have chaired a National Research Council panel that examined the issue of visibility in our national parks and wilderness areas. It found that the problem is indeed serious: Haze has reduced the average visual range to almost half of what it would otherwise be in much of the western United States and to one-fifth of what it would be in much of the East.
Furthermore, we found that because of flawed methods and inadequate efforts, existing strategies to control air pollution and improve visibility in our scenic parklands are doomed to failure.
Since passage of the 1977 Clean Air Act, the Environmental Protection Agency has concentrated on individual, large polluters. By concentrating on nearby polluters, the agency wrongly assumed that it could control the chief sources of pollution in the parks.
But most of the haze that obscures views and washes out colors in parks like Shenandoah or Yosemite is not caused by large, nearby sources of pollution. Rather, it has come from many sources spread over hundreds of miles.
Determining how much a single source contributes to haze tends to be time-consuming, expensive and unlikely to lead to definite answers. For example, the National Park Service's efforts to trace the contribution of a single power plant to haze in the Grand Canyon took several years and cost millions of dollars. But it still did not produce clear evidence about the station's contribution to the park's pollution.
Our panel determined that if the fight against haze is to be won, we must change our tactics. Federal and state governments need to attack haze on a regional basis. That means working to control many small sources of pollution as well as focusing on individual large polluters both nearby and far from the parks.
Also, tactics may need to differ from the West Coast to the East Coast. The major cause of reduced visibility in the eastern United States is sulfate particles, which are produced by sulfur dioxide emitted largely by coal-burning electric power plants. In the West, additional substances such as organic matter, soot, nitrates and soil dust are relatively more important, and these substances require different control mechanisms.
Acid-rain restrictions imposed by the 1990 amendments to the Clean Air Act will somewhat improve air quality and visibility in the East over the next two decades by reducing sulfur emissions. But the West will require a different and more comprehensive approach because of its wider variety of pollution sources and the fact that pollution there is not yet as intense as in the East.
Better visibility in our parks will not be attained quickly. Policy-makers need to establish a comprehensive national strategy to improve visibility on a regional scale, along with milestones against which progress can be measured.
At the same time, research must move forward to determine the nature and origins of haze in various areas. Atmospheric monitoring, computer modeling and emissions-control research and development all will be needed to fill gaps in our understanding. A broader segment of the scientific community needs to be involved in addressing visibility problems.
This additional study is clearly needed. But the Clean Air Act gives regulatory agencies the authority to act on the basis of current understanding. With so many visitors to our national parks going away disappointed, we should not hesitate.
Robert A. Duce is dean of the College of Geosciences and Maritime Studies at Texas A&M University.
National Academy Op-ed Service
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