[Determination of mercury, lead and cadmium in fish from the Rhine and Main using flameless atomic absorption].

From 1976 until 1982 854 fishes from the Rhine and in 1983 43 fishes from the Main-river were analysed for mercury, from 1980 until 1982 212 fishes from the Rhine and in 1983 43 fishes from the Main-river were analysed for lead and cadmium. The analytical behaviour of these elements with special emphasis on the digestion is described. The results demonstrate that the contamination of the fishes from the Rhine by mercury has decreased within the period. This becomes also evident by the decreasing number of samples which exceed the tolerances. For lead and cadmium no trend can be deduced from the results. The contamination, however is appreciably higher than in unpolluted waters. Cadmium and lead seem to increase in concentration during the course of the river as demonstrated by a comparison of results from different stretches of this river. BGA-guide values (Federal Office of Health) were exceeded in some samples.