Various sorts of water (e.g. bathing water, tap water) are frequently monitored for their microbiological quality. False analytical results may have economic and public health consequences such as: unnecessary delay in taking repaired drinking water system back into use, unnecessary corrective actions after tests with false positive results, unnecessary condemnation of water sources for e.g. food industry, unnecessary constraints on the trade of mineral water or shellfish, unnecessary condemnation of bathing beaches, illness caused by undetected microbes in polluted water, etc. Intercomparisons have indicated that 5-15 % of all results are incorrect. Stability is the main difficulty in developing microbiological RM's. There is evidence that good stability can be achieved by isolating microbes in milk in gelatine capsules.
Five intercomparisons have been conducted to study the stability of the materials during transport, reconstitution of lethally stressed micro flora and the various official tests for total coli and thermo tolerant coliforms. E. coli, E. Faecum and E. cloacae have been studied. The certification of E. faecum is foreseen for 1992.
Funding SchemeCSC - Cost-sharing contracts
11521 Athens 618
3704 HE Zeist
GL55 6LD Chipping Campden
K115 3NB Weybridge
8071 CJ Nunspeet
NW9 5HT London
1870 Frederiksberg C
6708 PD Wageningen
40064 Ozzano Dell'emilia Bologna