Atmospheric Deposition of Current-Use and Historic-Use Pesticides in Snow at National Parks in the Western United States

Abstract

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.

Distribution and Air–Sea Exchange of Current-Use Pesticides (CUPs) from East Asia to the High Arctic Ocean

“…In recent years, most data on CUPs in atmospheric and aquatic environment published in international journals were from North America. 4,6,8,9,11,16 That indicates most current studies are not more than nationwide, but actually sampling sites in the majority of studies even covered only a small geographical area (a small Environmental Science & Technology ARTICLE part of a country). Thus the global CUPs distribution is not well understood.…”

Increasing and decreasing trends of the atmospheric deposition of organochlorine compounds in European remote areas during the last decade

“…As observed in the polar regions (Cabrerizo et al, 2012;Halsall, 2004), field studies in Europe , western Canada (Davidson et al, 2003), South America (Grimalt et al, 2004a;Pozo et al, 2007) and the Tibetan Plateau among others, have shown that mountains can act as cold-traps for POPs or even organic compounds with limited atmospheric transport, e.g. currently used pesticides (Hageman et al, 2006). These previous studies have documented the overall accumulation process but the mechanisms by which these compounds are transported through the atmosphere and accumulate in these environments are largely unknown.…”

Temporal and spatial variation of atmospherically deposited organic contaminants at high elevation in yosemite national park, California, USA

“…Second, snowpack samples collected at the end of winter represent integration of chemical input over many months, whereas summertime samples may reflect conditions over much shorter time intervals. Third, although contaminant inputs are primarily regional during both summer and winter [8,28], contaminant inputs likely vary spatially more during summer than winter due to the more localized wind patterns during summer (e.g., up-valley winds [28]) than the widely circulating cyclonic storms during winter.…”

“…The present study focuses on the Sierra Nevada mountain range, which lies adjacent to one of the highest agricultural pesticide-use areas in North America, the Central Valley of California [4]. Even in the remote alpine zone at high elevation (i.e., near or above timberline, >2,750 m), the occurrence of pesticides and other airborne contaminants is well documented [5][6][7][8][9][10], and concern has arisen that airborne contaminants may be having adverse effects on biota at high elevation. For example, concentrations of DDT-related compounds and dieldrin in fish from the southern Sierra Nevada at high elevation exceeded human health thresholds for recreational fishing and/or wildlife health thresholds [11], and dichlorodiphenyldichloroethylene (DDE) in lake sediment exceeded guidelines for protection of benthic organisms [10].…”