Semi-quantitative evaluation of fecal contamination potential by human and ruminant sources using multiple lines of evidence.

摘要: Protocols for microbial source tracking of fecal contamination generally are able to identify when a is present, but thus far have been unable evaluate what portion fecal-indicator bacteria (FIB) came from various sources. A mathematical approach estimate relative amounts FIB, such as Escherichia coli, sources based on the concentration and distribution markers in feces was developed. The tested using dilute suspensions, then applied part an analytical suite contaminated headwater stream Rocky Mountains (Upper Fountain Creek, Colorado). In one single-source suspension, that not present could be excluded because incomplete marker specificity; however, human ruminant were detected whenever they present. mixed-feces suspension (pet human), minority contributor (human) at low enough preclude dominant E. coli sample. Without semi-quantitative described, simple detects human-associated samples would provided inaccurate evidence major stream. Upper Creek pattern general host-associated markers, nutrients, wastewater-associated chemical detections--augmented with local observations land-use patterns--indicated that, contrary expectations, birds rather than humans or ruminants predominant Creek. This new allocation, validated by controlled study application relatively setting, represents widely applicable step forward field contamination.