<< Back 6/19/02 Ozone advisory issued for Smokies SMN Great Smoky Mountains National Park reached maximum levels of unhealthy ozone pollution last week and ozone conditions are expected to remain at unhealthy levels at high-elevation sites, posing a threat to the health of park visitors. Park managers emphasized that this advisory is specifically for higher elevation areas while ozone levels at lesser elevations outside the park may be lower. The maximum eight-hour ozone averages measured at the park’s air quality stations were 101 ppb at Clingmans Dome, 99 ppb at Cove Mountain and 94 ppb at the Purchase Knob station. At Clingmans Dome a peak one-hour ozone level of 116 ppm was recorded at 3:00 p.m. Under federal and state standards in Tennessee and North Carolina, an 8-hour average ozone concentration of 85 ppb or greater is unhealthy. The exceedance last week marked the seventh and eighth times that unhealthy levels have been reached this year. Natural ozone levels are estimated to be 20-40 ppb. The U.S. Environmental Protection Agency (EPA) has identified several groups of people who are at risk from ozone exposure: (1) those with respiratory problems such as emphysema, asthma, and chronic bronchitis; (2) individuals engaging in heavy outdoor exercise either recreationally or at work as well as children at play; and (3) a few otherwise healthy individuals who are especially sensitive to ozone and suffer greater loss of lung function than the general population. These visitors may wish to refrain from strenuous outdoor activities while this condition is in effect. Ozone, considered a secondary air pollutant, is formed from primary emissions of nitrogen oxides (from coal-fired power plants, motor vehicles and factories) and volatile organic compounds in the presence of sunlight. Ozone pollution is a powerful respiratory irritant in some people, causing shortness of breath, coughing, wheezing, scratchy eyes, nose, and throat, and chest pain while breathing deeply. Visitors experiencing these symptoms are advised to reduce strenuous outdoor activity and take shelter indoors. Ozone pollution also is causing visible leaf injury to 30 species of vegetation at the park such as black cherry, yellow poplar, and tall milkweed. Typically, ozone levels in the higher elevations of the Smokies remain at dangerously high levels for a more extended period of each day than occurs in low elevations where the levels generally spike in late afternoon than drop rapidly in the evening. The park is now presenting air quality monitoring data to the public through a new computerized display located at Sugarlands Visitor Center and on its World Wide Web Site at http://www2.nature./nps.gov/ard/parks/grsm/grsmcam/grsmcam.htm. The data includes information on current visibility measurements, ozone pollution concentration levels, particulate matter, and real time digital camera pictures taken from the Look Rock Air Quality Monitoring Station.