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 A 2011 update is provided in the text below! The Knoxville region experiences a high amount of ground-level ozone and fine particulate matter, especially during the summer months. Ground-level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence  of sunlight (it takes the sun's heat as temperature and heat-energy to drive the reaction). Emissions from motor vehicles, industrial facilities, electric utilities (think coal-fired power plants) and lawn equipment are some of the major sources of NOx and VOCs. "Good" ozone is a gas that protects the Earth from ultraviolet sunrays in the upper layers of the atmosphere ("good up high") but when it is formed at ground level, it is harmful to our lungs, expecially those with respiratory diseases, can damage vital plant and water resources, and can affect the economy by detering tourists from visiting the region if its scenic beauty is hindered by smog ("bad nearby").Particulate matter is the term for particles found in the air, including dust, dirt, soot, pollen, smoke and liquid droplets. Fine particulate matter (PM-2.5), those smaller than 2.5 microns or micrometers in diameter, are of the greatest concern. These particles are so small that they can become lodged deep in your lungs or may even enter the bloodstream directly and cause health problems. 
Some particles are directly emitted into the air such as from vehicles, factories, construction, farm fields, quarrying and burning. Other particles are formed in the air when gases from burning fuels react with sunlight and water vapor.On April 15, 2004 the Environmental Protection Agency (EPA) designated several areas throughout the country as nonattainment for air quality. These areas have ozone and/or PM-2.5 levels higher than allowed under EPA's National Ambient Air Quality standards (NAAQS). These standards are designed to protect the public from exposure to unhealthy pollutants. In the Knoxville region, the counties designated nonattainment for ground-level ozone include Anderson, Blount, Jefferson, Knox, Loudon, Sevier and that portion of Cocke County within the Great Smoky Mountains National Park. These counties were categorized as basic nonattainment areas and will have to comply with more general nonattainment requirements in the Clean Air Act (we are currently in a period where our ozone nonattainment status may be increased to "marginal," which is a step worse than "basic"). Counties designated as nonattainment for PM-2.5 include Knox, Loudon, Anderson, Blount, and a portion of Roane. The only other county in East Tennessee that was recently designated nonattainment for one of these standards is Hamilton County (Chattanooga) for the 8-hour ozone standard, but they were redesignated attainment in 2008 largely due to putting a tailpipe inspection program in place in their community. These counties must meet attainment for ground-level ozone by June 2009 and for PM-2.5 by April 2010. There is not an immediate threat to lose transportation dollars (we are not severe enough in our not meeting the standards to warrant such action, yet), but if this area does not implement air quality regulations necessary to clean up our air by the prescribed time, there will then be a threat to lose transportation project funding. 2011 Update! On March 1, 2011, all of the Knoxville area counties that were designated nonattainment for the 8-hour ozone standard were redesignated attainment! Over the last 10+ years, although our ozone numbers do go up and down some, the overall trend has been down. A number of initiatives have helped reduce ozone formation in the area, alongside NOx and VOC reductions and TVA power plants and the cars and trucks on (and off) the nation's roads continuing to get cleaner. - Read updates to nonattainment areas (becoming attainment) from 2010 and 2011 on the EPA's Website here: http://www.epa.gov/airquality/greenbk/adden201012.html This is a big step in the right direction for the more populous central East Tennessee counties, but we are not in the clear yet. The EPA and the Obama Administration are eyeing further reductions to the 8-hour ozone standard to improve our health, and this action would likely push some or more counties in Tennessee and throughout the nation back into nonattainment. This summer (by July 31) is when the EPA will make a decision to push the 8-hour ozone standard from the current 84 ppb down to somewhere between 60-70 ppb (parts per billion). Here is a copy of a recent EPA statement (edits are in brackets): ------------- Under Administrator Jackson's leadership, in January [2010] the Environmental Protection Agency proposed stricter standards for smog - standards that would help prevent up to 12,000 premature deaths, 58,000 cases of aggravated asthma and save up to $100 billion dollars in health costs. The proposed standard would replace an existing standard set during the previous Administration, which many—including the Agency's independent team of expert scientists known as Clean Air Science Advisory Committee (CASAC)—believed did not go far enough to protect public health. Administrator Jackson proposed that EPA select a standard in the range that CASAC indicated would be protective of Americans' health. As part of EPA's extensive review of the science, Administrator Jackson will ask [has asked] CASAC for further interpretation of the epidemiological and clinical studies they used to make their recommendation. To ensure EPA's decision is grounded in the best science, EPA will review the input CASAC provides before the new standard is selected. Given this ongoing scientific review, a final standard—which will be in the range recommended by the CASAC—will be set by the end of July, 2011. S. William Becker Executive Director National Association of Clean Air Agencies ------------- Useful Resources (all will open in another window):
This text put together with help from the Regional Clean Air Coalition and data from the EPA. | |
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