The United States (U.S.) National Park Service has initiated research on the atmospheric deposition and fate of semi-volatile organic compounds in its alpine, sub-Arctic, and Arctic ecosystems in the Western U.S. Results for the analysis of pesticides in seasonal snowpack samples collected in spring 2003 from seven national parks are presented herein. From a target analyte list of 47 pesticides and degradation products, the most frequently detected current-use pesticides were dacthal, chlorpyrifos, endosulfan, and gamma-hexachlorocyclohexane, whereas the mostfrequently detected historic-use pesticides were dieldrin, alpha-hexachlorocyclohexane, chlordane, and hexachlorobenzene. Correlation analysis with latitude, temperature, elevation, particulate matter, and two indicators of regional pesticide use reveal that regional current and historic agricultural practices are largely responsible for the distribution of pesticides in the national parks in this study. Pesticide deposition in the Alaskan parks is attributed to long-range transport because there are no significant regional pesticide sources. The percentage of total pesticide concentration due to regional transport (%RT) was calculated for the other parks. %RT was highest at parks with higher regional cropland intensity and for pesticides with lower vapor pressures and shorter half-lives in air.

The core parks included three west coast (OLYM, MORA, and SEKI), three Alaska parks (NOAT, GAAR, DENA), and two parks in the Rocky Mountains (ROMO and GLAC). We selected two sampling sites (i.e. lakes) in each park, with the exception of NOAT and GAAR, where we sampled one site in each, for a total of 14 sites. Lakes were selected to have no glaciers in their watersheds, relatively simple bathymetry, minimal inlets and outlets and an established salmonid spp.population that we were permitted to sample. B.) Sample matrices and the rationale for their selection:The WACAP study was designed as a screening study to assess contaminant concentrations across large-scale spatial gradients and temporal scales relevant to western national parks. The seven ecosystem components selected for analysis were: air, snow, water, lake sediments, lichens, conifer needles, and fish. These components were chosen for the reasons described below.End-of-season snowpack samples contain an integrated record of wet and dry contaminant deposition occurring during the snow-accumulation season. A significant proportion of the contaminant load in snowpack may be delivered to the ecosystem during snowmelt (with specific fates varying by contaminant). We used snowpack samples, collected from the vertical face of snow pits dug from the snow surface to the ground, to calculate contaminant flux delivered via snow (3).We used passive air sampling devices (PASD) to: (a) obtain a measure of SOCs in ambient air by means of a simple, standardized technology to compare loadings among parks and across geographic and elevational gradients, (b) compare PASD and vegetation

Abstract. The cryosphere is an important component of global organic contaminant cycles. Snow is an efficient scavenger of atmospheric organic pollutants while a seasonal snowpack, sea ice, glaciers and ice caps are contaminant reservoirs on time scales ranging from days to millennia. Important physical and chemical processes occurring in the various cryospheric compartments impact contaminant cycling and fate. A variety of interactions and feedbacks also occur within the cryospheric system, most of which are susceptible to perturbations due to climate change. In this article, we review the current state of knowledge regarding the transport and processing of organic contaminants in the global cryosphere with an emphasis on the role of a changing climate. Given the complexity of contaminant interactions with the cryosphere and limitations on resources and research capacity, interdisciplinary research and extended collaborations are essential to close identified knowledge gaps and to improve our understanding of contaminant fate under a changing climate.