De microbiologische kwaliteit van hemelwater toegepastvoor toiletspoeling, schoonmaken en tuinsproeien - inventariserend onderzoek 2005

摘要

Rainwater collected in reservoirs and used for toilet flushing, forexample, is often fecally contaminated and sometimes contains pathogenicbacteria. Estimating risk of infection caused by use of this water, willrequire additional research for enumerating and typing pathogens and fordetermining exposure to the contaminated water. Rainwater at the sourceis not contaminated with potential human pathogenic micro-organisms, butmay become so at surface run-off and during storage in containers. Thismay occur when bird faeces runs off roofs, or rats or other animals haveaccess to rainwater reservoirs or open mains. Examination of collectedrainwater at four different sites in the Netherlands showed the presenceof faecal indicator bacteria as total coliforms, E. coli and intestinalenterococci in 28, 27 and 27, respectively, of the 28 samples examined. Each of the potential human pathogenic bacteria, Campylobacter andLegionella pneumophila, was detected once at one sampling site. Aeromonas and Clostridium perfringens, which may also cause disease inhumans, were detected in 20 and 23 of the 28 tested samples,respectively. Salmonella and Vibrio were not detected in any of thesamples. The presence of potential pathogenic micro-organisms inrainwater used for toilet flushing may have adverse health effects. However, on the basis of the above results, and because additional typingand exposure data are required, it is not yet possible to estimate therisk of infection at exposure to this water.