The two principal precursors of ozone—nitrogen oxides and volatile organic compounds—have diverse sources. Respiratory Illnesses

Throughout the 1990s, death rates from two respiratory illnesses— (1) chronic lung disease and (2) pneumonia/influenza—in North Carolina and Tennessee were consistently higher than the comparable national rates. TVA’s emissions of nitrogen oxide (an ozone precursor) were relatively stable during the 1990s; however, it estimates that its emissions of nitrogen oxides—during the warm-weather months when ozone levels peak—will decline 70 percent between 1999 and 2005. EPA also told us about this review. Briefing Section I: Overview

	Air Pollution and Respiratory Illnesses in and Near the Great Smoky Mountains National Park

		Briefings for Chairman Charles H. Taylor Subcommittee on Legislative House of Representatives March 1 and 22, 2001

As directed by House Report 106-1033 and as discussed with Chairman Charles H. Taylor, we focused on four issues: visibility, which is important to people who live near the park, visitors from other areas who travel to enjoy the park’s vistas, and others;  ozone, which can harm people, animals, and plants; respiratory illnesses, a manifestation of the harm from ozone and other causes; and  Tennessee Valley Authority’s (TVA) plans to reduce its emissions of sulfur dioxide and nitrogen oxides. In the east generally, and in the park specifically, most of these particles are sulfates, which are formed in the air from sulfur dioxide gas. 3. To generate electricity TVA relies primarily on coal.
Why GAO Did This Study

Concerns have been growing about the air quality, visibility, and respiratory illnesses around the Great Smoky Mountains National Park, which straddles the border between North Carolina and Tennessee. This report analyzes recent trends in and contributing factors to (1) visibility impairments, (2) ground-level ozone, and (3) respiratory illnesses.

What GAO Found

This report also examines the Tennessee Valley Authority's (TVA) plans to reduce its emission of regulated pollutants from generating electricity. Visibility impairments and ozone are largely attributable to the following three types of emissions: sulfur dioxide, nitrogen oxides, and volatile organic compounds. The counties that border the park generally have slightly higher mortality rates from two types of respiratory illness. The three types of emissions interact in the atmosphere to form ozone gas and sulfate particles, which are linked to respiratory illnesses. In response to federal laws and other factors, TVA is making substantial environment-related investments and expects to reduce its annual emissions of sulfur dioxide by 40 percent and its "ozone-season"' emissions of nitrogen oxides by 70 percent between 1999 and 2005.