When the American Lung Association's Annual "State of the Air" report first landed in the news in 2000, the media interest around the report exploded in Knoxville, Tennessee, which the report ranked as the 12th most ozone-polluted city in the U.S. Knoxville was a city known for its University of Tennessee football and women’s basketball teams, and being a gateway to the Great Smoky Mountains National Park—not for being one of the most polluted cities in America.

Fast forward to "State of the Air" 2017 when Knoxville achieved the city's best-ever report card, earning all passing grades under even more protective ozone standards and dropping way down to tie as the 104th most polluted city.

But it is not just the "State of the Air" that shows the improvements Knoxville's air quality has seen over the years. For the first time, Knoxville meets the official national standards for ozone, including the stronger standard adopted in 2015.

Despite all this progress, the future of clean air, for Knoxville and the rest of the country, is not guaranteed. As longtime expert on Knoxville's air quality Lynne A. Liddington explains: "We did not clean up our air overnight; it took decades. It would be so easy to look at the present and start relaxing our efforts. But we must be diligent in our efforts, realizing that the need for industry is vital to our nation, but that it must co-exist with our rights and desires to breathe clean air."

So how did Knoxville make such progress?

To learn more about how one city went from having some of the worst ozone pollution in the country to achieving remarkable reductions in ozone pollution levels, we sent some questions to Liddington, who is the director of Air Quality Management for the Knox County Health Department. Knox County, Tennessee, is where the city of Knoxville is located. Liddington has been the director of Air Quality Management since 1999, and has worked at the Knox County Department of Air Pollution Control since 1981.


Just how bad was the air pollution in Knoxville in the past, and where was it coming from? According to Liddington, really bad. "Industrial emissions in Knox County in the 1960s and 1970s included fluoride from a fertilizer plant; smoke and odor from asphalt plants; manganese, sulfite odor, acids and ammonia from an electric furnace operation; dusts from shale, cement and lime companies and monument works; odors from organic vapors, including methyl methacrylate, coal smoke and dust from an aggregate processor; paint spray; the usual fumes and smoke of foundry cupola emissions; and general smoke from combustion from the combustion of soft coal."

She went on to say, "Other sources of air pollution consisted of residential open burning of garbage, open burning of junk automobiles, dry cleaners, odors from rendering plants and meat, poultry and seafood packing plants, smoke and odor from asphalt road mix plants, automobile emissions and smoke and particulates from the burning of coal for heat in schools, businesses, apartment buildings and homes."

In other words, people were breathing TONS of dangerous stuff in the air. Knox County was found to have too much of two pollutants which had official limits: too much ozone pollution in 1990 and too much particle pollution (PM2.5) in 2005. Knox County was one of scores of metropolitan areas across the nation facing similar air pollution problems.

When states and the Environmental Protection Agency (EPA) identify an area that has too much of one of the nation’s most widespread and dangerous air pollutants, such as ozone, it is designated as a "nonattainment" area. This means that an area must clean up emissions to reach, or "attain," the official, health-based limits for that pollutant. That designation launches organized efforts by state and local officials to use the tools in the Clean Air Act to clean up the sources that produce the emissions that create the pollutant, with the goal of reducing pollution levels to meet the standard.

So, what changed? When asked what had the most impact in cleaning up the air in Knox County, Liddington said the Clean Air Act was key.

"Clearly, the Clean Air Act of 1970 and its amendments had the most positive impact in terms of improved air quality in Knox County," Liddington said. "Control Techniques Guidelines were adopted into the Knox County Regulations to clean up our existing industries. But it took lawsuits against the Tennessee Valley Authority to force the utility to install and operate scrubbers on its coal-fired power plants for Knox County's air quality to meet both the ozone and PM2.5 standards."

Liddington mentions several tools used to reduce air pollution, including the Control Techniques Guidelines, which provide effective steps to reduce the emissions from specific sources and scrubbers, which remove pollutants from power plants before they are released into the air.

On a more local level, Liddington said that cooperation has been key to continuing the efforts to clean up air pollution.

When asked which local efforts made a significant difference, she said that the formation of a unified front of 11 Tennessee counties in 2003, established to take measures necessary to clean up our air, was valuable. The formation of that coalition, Liddington said, included an "Air Quality Summit" held in Knoxville, with attendance by many area mayors, State of Tennessee officials and federal officials, and included Senator Lamar Alexander as a keynote speaker.

After the launch, Liddington said, "Regular monthly meetings were held for several years, continuing the focus on cleaner air and energy conservation and efficiency. Knox County led the way with an energy audit and efficiencies installed in Knox County Government buildings."

As mentioned earlier, Liddington acknowledges while great strides have been made, that doesn't mean that pollution reductions efforts are done. "It would be so easy to look at the present and start relaxing our efforts," she said. "We must be diligent."

Knoxville's progress has been remarkable, and many other cities and counties across the country have also achieved cleaner, healthier air, thanks to the Clean Air Act. You can take a minute today to help ensure that the nation continues to make progress under the Clean Air Act. Call on your members of Congress to protect the Clean Air Act, the law behind healthier air in Knoxville and across the country. We've made great strides, but there is still work to be done to achieve the goal of healthy air for all to breathe! Send a message to Congress today.

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