AIRBORNE CONTAMINANTS IN WESTERN NORTH AMERICAN NATIONAL PARKS--WHAT WE KNOW AND WANT TO LEARN

• Main Authors: D Landers, D Campbell, S Simonich, A Schwardt, L Geiser, D Jeffe, M Erway, T Blett, H Taylor
• Format: Text
• Language: unknown
• Published: 2005
• Subjects: Brooks Range; Alaska
• Online Access: http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=83667

The National Park Service initiated the Western Airborne Contaminants Assessment Project (WACAP) in 2002 to determine if airborne contaminants from regional or distant sources have an impact on remote (typically high elevation) western ecosystems, including Alaska. Eight National Park properties ranging from the Sierra Mountains to the South, the Brooks Range in Alaska to the North and West, and Rocky Mountains to the East have been selected for study. Fieldwork began in 2003 in 14 watersheds with spring snow sampling that will continue each year through 2005 in all 8 parks. Lake water, sediment cores, fish, and vegetation are sampled in one intensive effort (summer) at each site over the duration of the project to evaluate concentrations, pathways and impacts of semi-volatile organic compounds (SOC), mercury and metals. Atmospheric back trajectory modeling is performed for each site to determine the likely sources of contaminants. Snow sampling estimates direct atmospheric contaminant loading. Reproducing fish populations are evaluated for bioaccumulation of contaminants as well as for physiological and pathological response indicators. Lake sediment analyses compare historical and current levels of SOC and metal flux. Early results from snow indicate that a broad range of SOCs are deposited in all of the sites and that results from sites located in the same parks are comparable, even when separated by the continental divide. Contaminants in snowpack are also usually present in the lake water, but at lower concentrations. This is significant because it indicates that the airborne contaminants are moving through ecosystem components. In general, we detected fewer SOCs in the Rocky Mountains than in the Californian Sierra Mountains and contaminants present in the Rockies were also present in the Sierra. The most current contaminant results in other matrices will be presented and discussed in the context of the overall WACAP design and objectives.