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Volume 34, Issue 1 p. 42-48
Special Submission

Sources of Pathogenic Microorganisms and Their Fate during Land Application of Wastes

Charles P. Gerba

Corresponding Author

Charles P. Gerba

Department of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ, 85721

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James E. Smith

James E. Smith

Office of Research and Development, USEPA, Cincinnati, OH, 45268

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First published: 01 January 2005
Citations: 100

The opinions expressed in this article are those of the authors and do not necessarily reflect those of the USEPA.


The hazards associated with pathogens in land-applied animal and human wastes have long been recognized. Management of these risks requires an understanding of sources, concentrations, and removal by processes that may be used to treat the wastes; survival in the environment; and exposure to sensitive populations. The major sources are animal feeding operations, municipal wastewater treatment plant effluents, biosolids, and on-site treatment systems. More than 150 known enteric pathogens may be present in the untreated wastes, and one new enteric pathogen has been discovered every year over the past decade. There has been increasing demand that risks associated with the land treatment and application be better defined. For risks to be quantified, more data are needed on the concentrations of pathogens in wastes, the effectiveness of treatment processes, standardization of detection methodology, and better quantification of exposure.