Smog in Ol' Smoky
Take a look up in the Great Smoky Mountain National Park on a bad pollution day. You can see smog vividly.
Jim Renfro, air resources specialist and an expert in biological processes for the National Park Service, sees it every day on this job. He says surveys of park visitors show that people come mainly for the scenery. (Although researchers don't ask about the need humans seem to have to get close to nature. This is what scientist and Pulitzer Prize-winning author E.O. Wilson of Harvard calls "biophilia.")
When those people come to the Smokies, as they do by the car, truck, van, RV, and bus load, they tend to notice when it's hazy, and wonder if that's how the Smokies got their name. For the record, the haze is not why the Smokies are called the Great Smoky Mountains. The Cherokee Indians called this "the land of blue mist," which was due to the "ethereal blue mist that once surrounded the mountains like a transparent veil," according to John Nolt, a philosophy professor at the University of Tennessee and author of What Have We Done.
The book is due out soon from Earth Knows Publications of Washburn, Tennessee. Nolt says early European settlers named the Smoky Mountains, later changed to the Great Smoky Mountains to entice tourists. He says the original blue mist consisted of water vapor and organic compounds released by trees.
"Today, most often in the summer months, the 'smoke' of the Smokies is supplanted by white, brown, or grey haze," he says. This haze consists of smoke, sulfate particles from the burning of coal at power plants, "and the more noxious volatile organic compounds that billow from the exhaust pipes of the millions of cars and trucks moving ceaselessly through the lands below."
How much smog should be allowed in the air of a national park, land set aside years ago to be preserved for future generations? How much can be considered safe to people, plants, and wildlife?
Pollution problems in the national park come in three forms: visibility, ozone, and acid deposition. Acid rain was addressed in the 1990 amendments to the Clean Air Act and is on the way down, although its effects will be with us well into the next century. The visibility problem is getting worse and probably won't get much better anytime soon, no matter what happens in Washington. It used to be, in the 1940s, that on an average day in the Smokies, you could see for 90 miles. In five decades that has gone down 80 percent, to an average of 22 miles and only 12 in the summer. When the haze is at its thickest, Nolt says, a mountain peak a mile away can be nearly invisible. The ambient air quality rules now under consideration mainly concern ozone and particulates, major contributors to the visibility problem, but even if passed in their present form, they will not completely solve either problem, experts say.
"They do not go far enough, but we support it as a reasonable step to take," Renfro says. "It will help."
A person with asthma would have trouble breathing on a hazy day in the Smokies, especially in the high elevation areas. In one of America's most cherished and visited national parks, the dangerous kind of ozone is relentless. Cooler air carries it out of Knoxville at night while nitrous oxide eats it out of the air. Yet the highest points in the mountains suffer year round, day and night, according to Renfro. Studies show the primary pollutants present in the East Tennessee/Western North Carolina area are nitrogen oxides and sulfur dioxide, which contribute to the fine particulates being debated in the ambient air quality issue, and combine with ozone to create smog. While some nitrogen oxides occur naturally in the environment, numerous studies show they can be toxic to humans and biota and also perturb the chemistry of the global atmosphere.
The largest amount of NOx emissions, 45 percent, comes from cars and trucks on America's streets and highways, from internal combustion engines. Power plants account for 35 percent of NOx in the air, and industrial sources account for 25 percent, primarily from boilers. Eighty-two percent of the sulfur dioxide, the most prevalent and harmful of air pollutants, is produced from burning fossil fuels.
Of that, electric utilities are responsible for 39 percent locally, mostly TVA plants in Bull Run and Kingston. Automobiles account for 33 percent. Industry accounts for 13 percent. According to a study cited in Nolt's book, the worst local industrial polluters are Lenzing Fibers in Lowland, Eastman in Kingsport, and Champion in Canton, North Carolina. Another 12 percent comes from off-road vehicles and small motors, including planes, trains, boats, lawnmowers, chain saws, weed-eaters, leaf blowers, and the like, which are largely unregulated.
Other studies show that tall milkweed, a food source for many insects, sassafras trees, and black cherry, a food source for Black Bear, are already in trouble from ambient air pollution, in addition to acid rain. Yellow poplar are also being lost, and scientists worry that white pines are suffering as well, although studies at this point are inconclusive. At least 90 species of plants show some damage. Fish and the life of streams in the Smokies are more affected by acid levels than ozone or particulates, although at high enough levels, they can cause problems, Renfro says.
He says the levels of human-made pollutants have declined 60 percent overall for the past 50 years, yet sulfur dioxide levels have gone up. By the peak year for all air pollution in 1970, 2.2 million tons of sulfur made its way into the air in the U.S., up from 400,000 tons in the late 1940s. In the Southeast, the level today is about 10 million tons a year from all sources and is especially troublesome to humans, animals, and plants in the summer, when the highest pollution levels of the year coincide with bad weather conditions. Humidity, heat, and sunlight combine to create a chemical reaction, transforming sulfur dioxide into sulfates. The summer average sulfate concentration in the park is now 42 times higher than natural levels.
"Unhealthy air from ozone and particulates in this area is way too high now for active healthy adults and for those with disabilities," Nolt says. "It's about time we did something about it."
— G.W.
To see pictures of the haze in the Smokies, and to learn more about the air quality debate, visit Glynn Wilson's journalism page on the world wide web.