title: Occurrence of moulds in drinking water.
abstract: OBJECTIVE
  In order to determine the occurrence of filamentous fungi in public drinking water systems in Norway, water from 14 water supply networks from all over the country was sampled and analysed. Networks with both ground and surface water sources were included in this study.
  
  
  RESULTS
  During a one-year period, 273 water samples were collected. Frequencies of fungi in samples from raw water, treated water and from home and hospital installations were determined on the basis of incubation of 100 ml membrane-filtered samples on dichloran 18% glycerol agar media. Filamentous fungi were recovered from 62% of all samples. In ground water 42.3% of the samples were positive for mould growth, while surface waters yielded 69.7% positive samples.
  
  
  CONCLUSIONS
  The risk to recover moulds from surface water is three times higher compared with ground water. It is more likely to detect moulds in cold waters and showers than in hot waters.
  
  
  CONCLUSIONS
  By analysing the water reaching the consumers, the results reported in present study indicate that filamentous fungi in drinking water is not negligible, and that moulds should be considered as part of the microbiological analysis parameters in drinking water.
authors.affiliation: National Veterinary Institute, Section for Food and Feed Microbiology, Oslo, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Hageskal
authors.forename: P
authors.initials: P
authors.lastname: Gaustad
authors.forename: B T
authors.initials: BT
authors.lastname: Heier
authors.forename: I
authors.initials: I
authors.lastname: Skaar
mesh_terms: D003470:Culture Media; D004326:Drinking; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water / Q000382:microbiology; D005658:Fungi / Q000302:isolation & purification*; D006358:Hot Temperature; D009664:Norway; D018570:Risk Assessment / Q000379:methods; D012621:Seasons; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D003470:Culture Media