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

This Article Figures Only Full Text Free Full Text (PDF) Free An erratum has been published Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (18) Citing Articles via Google Scholar Google Scholar Articles by Darnault, C. J. G. Articles by Parlange, J.-Y. Search for Related Content PubMed Articles by Darnault, C. J. G. Articles by Parlange, J.-Y. GeoRef GeoRef Citation Agricola Articles by Darnault, C. J. G. Articles by Parlange, J.-Y. Related Collections Microorganisms Vadose Zone Processes and Chemical Transport

ORIGINAL RESEARCH PAPERS

Preferential Flow and Transport of Cryptosporidium parvum Oocysts through the Vadose Zone

Experiments and Modeling

^a Department of Biological and Environmental Engineering, Riley-Robb Hall, Cornell University, Ithaca, NY 14853
^b INRA, Unité d'Agronomie de Laon-Peronne, 02007 Laon Cedex, France
^c USDA-ARS, Campbell Natural Resource Conservation Center, Watkinsville, GA 30677
^d Department of Microbiology, Cornell University, Ithaca, NY 14853
^e Laboratory of Geoenvironmental Engineering and Science, Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853
^* Corresponding author (tss1{at}cornell.edu).

Received 27 June 2003.

As a result of Cryptosporidium parvum in drinking water, several outbreaks of cryptosporidiosis have occurred in the last 10 yr. Although it is generally believed that movement of pathogens through the soil is minimal, recent research has shown that appreciable numbers of C. parvum oocysts may be transported via preferential or fingered flow to groundwater. The objective of the present research was to further investigate and model the transport of oocysts through preferential flow paths in the vadose zone under a "worst-case" scenario. This was studied by adding calves feces containing C. parvum oocysts with a Cl^– tracer to undisturbed silt loam columns and disturbed sand columns during a simulated steady-state rain. The sand columns exhibited preferential flow in the form of fingers whereas macropore flow occurred in the undisturbed cores. In the columns with fingered flow, oocysts and Cl were transported rapidly with the same velocity through the columns. Although only 14 to 86% of the amount applied, the number of oocysts transported across the columns was several orders of magnitude above an infective dose. The macropore columns had only a very limited breakthrough of oocysts, which appeared several pore volumes after the Cl broke through initially. A simulation model for the transport of oocysts via preferential flow was developed on the basis of an existing preferential flow model for nonadsorbing solutes, with addition of a first-order sink term for adsorbance of the C. parvum to the air–water–solid (AWS) interfaces, and with velocity and dispersivity parameters derived from Cl^– transport. The breakthrough of C. parvum oocysts could be described realistically for the sand columns. However, the model could not describe oocyst transport in the columns with macropores.

Abbreviations: AWS, air–water–solid • PBS, phosphate-buffered saline

This article has been cited by other articles:

				J. A. Guzman, G. A. Fox, R. W. Malone, and R. S. Kanwar Escherichia coli Transport from Surface-Applied Manure to Subsurface Drains through Artificial Biopores J. Environ. Qual., October 29, 2009; 38(6): 2412 - 2421. [Abstract] [Full Text] [PDF]

				X. Peng, T. Murphy, and N. M. Holden Evaluation of the Effect of Temperature on the Die-Off Rate for Cryptosporidium parvum Oocysts in Water, Soils, and Feces Appl. Envir. Microbiol., December 1, 2008; 74(23): 7101 - 7107. [Full Text] [PDF]

				T. Harter, E. R. Atwill, L. Hou, B. M. Karle, and K. W. Tate Developing Risk Models of Cryptosporidium Transport in Soils from Vegetated, Tilted Soilbox Experiments J. Environ. Qual., January 4, 2008; 37(1): 245 - 258. [Abstract] [Full Text] [PDF]

				A. J. Hamilton, F. Stagnitti, X. Xiong, S. L. Kreidl, K. K. Benke, and P. Maher Wastewater Irrigation: The State of Play Vadose Zone J., November 20, 2007; 6(4): 823 - 840. [Abstract] [Full Text] [PDF]

				D. E. Rupp, R. E. Peachey, K. L. Warren, and J. S. Selker Diuron in Surface Runoff and Tile Drainage from Two Grass-Seed Fields J. Environ. Qual., January 5, 2006; 35(1): 303 - 311. [Abstract] [Full Text] [PDF]