Air Quality
Vital Signs Included in Protocol
- Ozone
- Atmospheric deposition (wet and dry)
- Visibility and particulate matter
Parks Where Protocol Will Be Implemented
- BIBE (ozone, wet and dry deposition, visibility and particulate matter)
- CAVE (ozone)
- GUMO (ozone, wet and dry deposition, visibility and particulate matter)
Justification/Issues Being Addressed
Diminishing air quality is a concern in a number of national parks (NPS ARD 2002). Most parks in the CHDN are located some distance from urban centers in Texas and Mexico. Additionally, significant energy development near several network parks in southeastern New Mexico and West Texas from oil and gas development, and in Central Texas with coal-fired power plants will likely increase pollution of nitrates and sulfates. CHDN parks are affected by pollution from these cities and energy development projects (whether nearby or distant), and experience poor air quality due to ozone, nitrogen oxides, sulfur dioxide, volatile organic compounds, particulate matter, and toxins. Influenced by weather patterns, atmospheric pollutants are carried by the wind, are broken down by high temperatures and radiation, and are then deposited as wet and dry particles in the air, water, soil, vegetation, and on wildlife and humans. Atmospheric deposition of nitrogen and sulfur compounds can alter soil processes (e.g., soil nutrient cycling), effect plant species composition, directly injure vegetation, affect stability of biological systems, and impair water quality (Fenn et al. 2003). Air pollutants that decrease visibility can also affect human health, impair viewsheds, and degrade the aesthetic appeal of a national park (Malm 1999). Consequently, protection of air quality has become a priority in national parks and a core vital sign for monitoring in many networks (Maniero 2001).
Under the Clean Air Act of 1972 and 1990 amendments, protection of air quality is required in all U.S. National Parks >5,000 ac (labeled as Class I areas). The CAA gives non-attainment, Class I areas the greatest protection against further deterioration and requires monitoring to confirm that air quality and visibility improve or, at minimum, do not further degrade. In addition, according to each NPS park’s GPRA mandate, land managers in Class I parks are required to provide recommendations on how to protect air, natural, and cultural resources in the park. To evaluate these hazards to ecosystem and human health, it is important to monitor air quality conditions and their interactions with the physical and biological components of ecosystems. Additionally, monitoring of these vital signs will provide information for assessing temporal trends in air quality of individual Class I CHDN parks and generalized trends for broader regions (NPSARD 2002).