title: The impact of land use on microbial surface water pollution.
abstract: Our knowledge relating to water contamination from point and diffuse sources has increased in recent years and there have been many studies undertaken focusing on effluent from sewage plants or combined sewer overflows. However, there is still only a limited amount of microbial data on non-point sources leading to diffuse pollution of surface waters. In this study, the concentrations of several indicator micro-organisms and pathogens in the upper reaches of a river system were examined over a period of 16 months. In addition to bacteria, diffuse pollution caused by Giardia lamblia and Cryptosporidium spp. was analysed. A single land use type predestined to cause high concentrations of all microbial parameters could not be identified. The influence of different land use types varies between microbial species. The microbial concentration in river water cannot be explained by stable non-point effluent concentrations from different land use types. There is variation in the ranking of the potential of different land use types resulting in surface water contamination with regard to minimum, median and maximum effects. These differences between median and maximum impact indicate that small-scale events like spreading manure substantially influence the general contamination potential of a land use type and may cause increasing micro-organism concentrations in the river water by mobilisation during the next rainfall event.
authors.affiliation: Institute for Hygiene & Public Health, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany. Electronic address: christiane.schreiber@ukb.uni-bonn.de.
authors.forename: Christiane
authors.initials: C
authors.lastname: Schreiber
authors.affiliation: Institute for Hygiene & Public Health, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany. Electronic address: andrea.rechenburg@ukb.uni-bonn.de.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rechenburg
authors.affiliation: Institute of Geography, School of GeoSciences, University of Edinburgh, Drummond Street, EH8 9XP Edinburgh, Scotland, UK. Electronic address: e.rind@ed.ac.uk.
authors.forename: Esther
authors.initials: E
authors.lastname: Rind
authors.affiliation: Institute for Hygiene & Public Health, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany. Electronic address: thomas.kistemann@ukb.uni-bonn.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kistemann
mesh_terms: D000383:Agriculture; D001419:Bacteria / Q000302:isolation & purification; D003458:Cryptosporidium / Q000302:isolation & purification; D004784:Environmental Monitoring / Q000379:methods*; D004787:Environmental Pollution / Q000032:analysis*; D005858:Germany; D016829:Giardia lamblia / Q000302:isolation & purification; D008372:Manure / Q000382:microbiology; D011891:Rain; D045483:Rivers / Q000382:microbiology* / Q000469:parasitology*; D012988:Soil Microbiology; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D008372:Manure; D014873:Water Pollutants
keywords: Environmental hygiene; Land use; Non-point sources; Run-off; Surface water pollution