America's crown jewels are losing their sparkle

IT'S summer now and millions of Americans are anxiously making their plans to get out of the cities and enjoy our national parks. Americans can proudly boast of having the best park system in the world. The parks preserve for all time the great natural wonders, and the great buildings, monuments, and battlefields which played such vital parts in our rich history. But the places we have set aside to be enjoyed forever are in great danger. A family who drives for days to reach the rim of the Grand Canyon now may excitedly jump from their car only to stare into a smog bank. A hiker seeking a quiet escape by strolling through the forest of Great Smoky Mountains Park may now encounter a grove of dead and dying red spruce trees. A visitor trying to understand the momentous battle at Gettysburg may have trouble reading and understanding the crumbling and corroding stone and bronze monuments and statues.

Our park system is being victimized by dirty air. Today, air pollution is an urban problem which city dwellers cannot necessarily escape by visiting the parks. The House Subcommittee on National Parks and Recreation recently finished two days of hearings on park air quality, listening to dozens of witnesses, including scientists and superintendents of national parks in nearly every region of the country. What we heard is alarming.

Air pollution does not respect park boundaries. It floats over the canyonlands of the Southwest, and it obscures the views from the top of the Blue Ridge Mountains of Shenandoah National Park. It clouds the view of El Capitan in Yosemite, and it shortens the vast distances once visible from the top of Bryce Canyon in Utah.

Air pollution is much more than a visibility problem. Among the gases and minute particles floating along in the dirty air are some real killers. Ozone, a product of nitrous oxide, occurs naturally in small amounts. But the amounts floating into our parks are so abnormally high, because of pollution, that trees are dying.

From coast to coast, park superintendents and scientists told us trees are turning yellow, tops are thinning, and growth rates are declining. In California's Sequoia-Kings Canyon National Park, the giant sequoias and ponderosa pines are showing significant ozone damage. On the Maine coast, scientists are noting the same damage to Eastern white pine trees. Similar problems are reported at dozens of parks in between. The superintendents of Great Smoky Mountains in the Southeast showed us a cross section of a pine tree which clearly showed shrinking growth rings, the same characteristic noted in Germany's Black Forest trees just a few years ago which led to the dying Black Forest phenomenon today.

The list of effects does not end with smoggy vistas and damaged trees. When rainfall absorbs the gases and tiny solid particles in the air, it falls to earth as acid rain. Scientists are finding that even the highest, most remote areas of our parks, such as the high alpine lakes and streams in the Rocky Mountains are vulnerable to acid rain. In fact, because of the soil conditions, the high altitude lakes may be the most vulnerable, because these environments have little ability to neutralize the acidity in the rainfall.

Acid rain threatens to turn our seemingly unpolluted remote waters into places where fish cannot reproduce. If you are a fly fisherman dreaming of a chance to fish Yellowstone's blue ribbon trout streams, today's dream may well be tomorrow's nightmare.

Air pollution damages do not end with the trees and lakes. Our manmade environment is jeopardized too. A representative of the American Institute of Architects told us acid rain is steadily deteriorating our ``Built'' environment. From pre-Columbian Indian cliff dwellings of the Southwest to the metal statues of Gettysburg, to the Statue of Liberty in New York Harbor, air pollution is pitting, flaking, and corroding away our great historic treasures.

It is the job of the National Park Service to preserve and protect these parks which often are described as our country's ``Crown Jewels.'' But the park ranger's work is on the ground, in the park. The problem begins out of the park, often hundreds or even thousands of miles away, in the form of emissions from cars, factories, smelters, or power plants. The Clean Air Act sets the standards for emissions. Anyone who goes to a national park to seek refuge from the pollution of the cities only to find more of the same, has to ask, ``Is the Clean Air Act living up to its name?''

Scientists in the parks told us they are noticing the decline, and sometimes the total disappearance, of lichens from park ecosystems.

These tiny, delicate, primitive plants which cling to rocks and trees are especially susceptible to acid rain. Scientists tell us lichens are a good indicator species -- a canary-in-the-mine which can warn of greater dangers for other species. That analogy can be carried a step further. Our national parks are set aside to be preserved in their natural state for all time. They are to the United States as the proverbial canary is to the miner.

If we are beginning to see danger signs inside the parks, then how good a job of controlling air pollution are we doing elsewhere?

United States Rep. Bruce F. Vento (D) of Minnesota is chairman of the House Subcommittee on National Parks and Recreation.