HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aston, L. S. Articles by Seiber, J. N. Search for Related Content PubMed Articles by Aston, L. S. Articles by Seiber, J. N. Agricola Articles by Aston, L. S. Articles by Seiber, J. N.

Fate of Summertime Airborne Organophosphate Pesticide Residues in the Sierra Nevada Mountains

Department of Environmental Toxicology, University of California, Davis, CA 95616;

James N. Seiber^*

Center for Environmental Sciences and Engineering and Department of Environmental Resource Sciences, University of Nevada, Reno, NV 89557.

^* Corresponding author (jseiber{at}med.unr.edu).

ABSTRACT

This study examines the processes of dilution, degradation, and sorption to plant foliage of organophosphate (OP) pesticides during the summertime in an air corridor originating in the southern Central Valley of California and moving into the nearby Sierra Nevada mountains. Residues of chlorpyrifos, methidathion, and their oxons were examined in air and pine needles at three sites in the southern Sierra to delineate the role these processes play in the atmospheric fate of these residues. At the site closest to the Central Valley, we found relatively high levels of parent OPs and oxons in needle and air samples. At higher elevations needles contained lesser amounts of OP residues and at lower frequency, while air primarily contained the oxon form. With increasing elevation the ratio of thion to oxon form of chlorpyrifos in air decreased from 1.85 to 0.46 indicating that atmospheric oxidation was occuring. Based on the amounts of foliar deposition found, we estimate that during summer months nearly 16 kg of chlorpyrifos and its oxon may enter Sequoia National Park plant foliage. We deduce that for airborne OP insecticides, foliar deposition is a significant summertime fate process, along with atmospheric degradation and dilution.

This article has been cited by other articles:

				K. Ohyama, J. Angermann, D. Y. Dunlap, and F. Matsumura Distribution of Polychlorinated Biphenyls and Chlorinated Pesticide Residues in Trout in the Sierra Nevada J. Environ. Qual., September 1, 2004; 33(5): 1752 - 1764. [Abstract] [Full Text] [PDF]