Author: Dan Shelton, Research Leader, Environmental Microbial Safety Lab, Agricultural Research Service, U.S. Department of Agriculture, sheltond@ba.ars.usda.gov
In general, yes. Runoff is the primary source of pathogen contamination from animal manures. Limited research, however, suggests that there may be other less common modes of transport, resulting in human exposure. For example, some pathogens can be aerosolized during manure handling and transported over relatively short distances by prevailing winds, although most die rapidly from exposure to UV light and desiccation. Alternatively, wildlife (e.g., geese, wild pigs) may ingest pathogens while foraging in areas containing manure/feces and subsequently excrete the pathogens in surface waters or on produce. Finally, insects (e.g., flies) may inadvertently spread pathogens from manure or feces to nearby areas where humans may be exposed.
