[Coprosterol as chemical indicator in coastal seawater (author's transl)].

As bacteriological examination of water often needs a longer time, it was tried to use chemical indicators for detecting sewage pollution of water. Such a chemical indicator is coprosterol, a sterin derivative, which is discharged from human and animal enteric systems. For epidemic evaluations, E. coli, normally not present in pure water, is a good fecal bacterial indicator. Wether there does exist a certain parallelity of the amount of coprosterol and the presence of E. coli, water from bankfiltration systems and coastal seawater were examined. The presence of E. coli was not in every case accompanied by a positive coprosterol test, so that epidemic evidence is not shown by the latter. Nevertheless, the test may be good to evaluate mixing procedures between two different kinds of sewage polluted water or between groundwater and surface water.