[Microbiological public health aspects in the use of rain water as water reservoirs for toilet flushing, garden irrigation and laundry].
From a total of 102 rain water cisterns in use for toilet flushing, garden irrigation and laundering washing about 1,600 water samples were collected and subjected to microbiological analysis. The assays included aerobic heterotrophic microorganisms growing at 20 and 37 degrees C, respectively, as well as the identification of Escherichia coli, coliform organisms, faecal streptococci, Pseudomonas aeruginosa, staphylococci, yersiniae, salmonellae, shigellae, legionellae and yeasts. The median of the total number of cells per ml was 1,200 at 20 degrees C and 230 at 37 degrees C, respectively. Approximately 26 E. coli cells and 198 coliform organisms (median values) were found per 100 ml. In the case of cisterns manufactured of plastic the total number of cells was generally found to be lower than in samples collected from concrete or brick-made storage tanks. With the exception of the ubiquitously distributed organism Pseudomonas aeruginosa (found in 11.8% of the samples) and salmonella in only one sample, no other pathogens were detected. More than 95% of all analysed samples met the quality standards for bathing waters as set by the European Community. Provided certain precautions are taken, such as strict separation of mains for drinking water and rain water, as well as correct labelling of pipelines and collection sites, the use of rain water for toilet flushing, garden irrigation and laundry washing presents no unacceptable risk to public health.
Holländer
R
R
Landesuntersuchungsamt für Chemie, Hygiene und Veterinärmedizin, Bremen.
Bullermann
M
M
Gross
C
C
Hartung
H
H
König
K
K
Lücke
F K
FK
Nolde
E
E
D000383:Agriculture; D015169:Colony Count, Microbial; D005858:Germany; D006801:Humans; D007846:Laundering; D011634:Public Health; D011786:Quality Control; D011891:Rain; D014038:Toilet Facilities; D014871:Water Microbiology
Mikrobiologisch-hygienische Aspekte bei der Nutzung von Regenwasser als Betriebswasser für Toilettenspülung, Gartenbewässerung und Wäschewaschen.