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United States Department of Agriculture

Agricultural Research Service

Title: Evaluating Transport of Cryptosporidium Oocysts Through Soils Using Polystyrene Microsphere Surrogates

Authors
item Endale, Dinku
item Young, M -
item Pennell, K -
item Fisher, Dwight
item Steiner, Jean
item Amirtharajah, A -

Submitted to: Georgia Water Resources Conference
Publication Type: Proceedings
Publication Acceptance Date: March 26, 2001
Publication Date: N/A

Technical Abstract: Cryptosporidium parvum causes gastroenteritis in humans and is now recognized as an emerging pathogen. The inactive form, known as an oocyst, is excreted in the feces of infected animals and humans into the environment. Little is known about the transport of C. Parvum oocysts through soil to reach and contaminate water bodies. A 40x30-m site at the outlet of an 8-ha grazing catchment just above a spring was instrumented t conduct water budget analysis to evaluate soil-water and particle transport. A tracer experiment using polystyrene microspheres, as surrogates to the oocysts, showed that microspheres had migrated through unsaturated soil to reach the ground water and spring within 20 days after injection 14-m upstream of the spring. Microspheres continued to be detected in small numbers at sampling sites especially after rainfall events. Internal drainage in soil profile controlled the rapid response of the spring flow following precipitation events. Water drainage and particl transport through preferential flow pathway is more likely when soil water storage is elevated. This suggests subsurface transport of Cryptosporidium would most likely occur during period of high soil water storage and precipitation typically in the winter and early spring in the Southern Piedmont.

Last Modified: 8/21/2014
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