The Western Airborne Contaminants Assessment Project (WACAP) was conducted from 2002-2007 to determine the risk from airborne contaminants in western national parks. It was designed as a screening study at a broad spatial and temporal scale.
fish lake sediment lichens conifer needles snow water air
Focus was on semi-volatile organic compounds and heavy metals: Historic use pesticides Current use pesticides Industrial/urban use compounds Combustion byproducts Mercury
Airborne contaminants were found in all WACAP parks. Levels of mercury and other contaminants in some fish samples exceeded wildlife and human health thresholds.
The National Park Service sponsored three regional interagency workshops to explore ways to continue to address air toxins in national parks and other protected areas. Pacific Northwest (PNW) workshop: 10 U.S. and Canadian university, state and federal organizations represented. Attendees divided into three breakout groups to identify and prioritize data needs. All three breakout groups determined the top priority was establishment of an interagency contaminants workgroup focused on issues in the PNW.
The Workgroup formed in 2011 and meets every other month via conference call. Workgroup objectives: Develop a data clearinghouse and a forum to facilitate collaboration and coordination of contaminant monitoring and research activities in the region. Prioritize contaminant-related research and monitoring needs in the PNW, collaborate on funding, and conduct monitoring and research projects. Coordinate outreach efforts and products related to contaminants issues in the region.
Developed a website that improves access to data. Collaborative efforts have resulted in sharing of archived samples and data as well as low cost/no cost sample analyses at agency laboratories. Greatest benefit has been improved understanding and building of relationships among agencies.
Map of Federal/Tribal lands and air pollution sources in the PNW (produced by NPS 2014). Triangles indicate point sources greater than 100 tons/year of nitrogen oxides.
Nitrogen (N) is a pollutant of particular interest in the PNW because: While sulfur is the pollutant of most concern in the eastern U.S., there are many more sources of N than of sulfur in the west We are concerned about both nutrient enrichment and acidification. Effects can include: Changes in soil and water chemistry Increase in invasive species Decline in native species health, longevity and biodiversity Negative effects on recreational We have resources with known or suspected sensitivity to N including high elevation lakes, alpine and sub-alpine soils and vegetation, desert grasses and lichens.
A critical load is based on studies or modeling and is the amount of pollution below which harmful environmental effects are not expected to occur. A target load identifies an acceptable amount of pollution and is based on policy, economic, temporal or other considerations. A target load may be higher or lower than a critical load.
Potential adverse effects from atmospheric N deposition in the PNW (produced by USFS, 2013).
Potential adverse effects from atmospheric N deposition in the PNW (produced by USFS, 2013). Target Load? Critical Load
Potential adverse effects from atmospheric N deposition in the PNW (produced by USFS, 2013). Target Load? Critical Load Target Load?
The National Park Service, U.S. Forest Service and U.S. Geological Survey are developing an approach to identify and use N critical loads and target loads to protect resources in the PNW. Ideally, critical loads will be developed for several biological resources and ecological endpoints. First step is publication of a report that: Summarizes available information about critical loads in the PNW Identifies current research efforts and prioritizes data needs Data needs are prioritized regionwide and for each Level 1 ecoregion
From the Commission for Environmental Cooperation, 1997
Regionwide Improve accuracy of N deposition estimates Explore interactions of N deposition and climate change Determine N sensitivity of biological soil crusts Marine West Coast Forests and Northwestern Forested Mountains Ecoregions Improve understanding of the sensitivity of high-elevation lakes and streams to N deposition Determine the influence of natural lake, stream and soil N levels on critical loads North American Deserts Ecoregion Determine N sensitivity of several native and invasive plant species
Encourage and support N critical loads research. Develop a common rationale for determining N target loads. Develop maps showing areas that exceed N critical loads and/or target loads. Solicit input from U.S EPA, state air quality agencies and other stakeholders. Implement use of N critical loads and target loads through agency planning and policy mechanisms. Work with stakeholders to identify sources that contribute to N exceedances and achieve emission reductions.