Biological health risk assessment
Quality of water intended for human consumption ? Control objectives and issues

It is often difficult, and time-consuming, to count pathogenic micro-organisms in water, mainly because of their small numbers. For some micro-organisms, analytical methods are insufficiently developed (impossible culture on medium, etc.).

It therefore seems preferable to count pathogenic indicator micro-organisms, which are generally easier to detect and whose presence corresponds to the possibility of finding a given pathogen or group of pathogens.

• Special features of pollution monitors

  Pollution indicators have been defined on a number of occasions, and were reiterated in 1972 at the Stockholm conference organized by the United Nations. There is no such thing as an ideal indicator. The best one is the one...