Traces of Cu, Mn and Zn in Aquatic Animals, Water and Sediments from the Cris River Basin West Romania. Part II: Distribution Study

The paper presents the determination of Cu, Mn and Zn (TRT r.f.CCP-AES, FAAS) in water, sediment and aquatic animals (fish fillet, freshwater molluscs gills and muscles) collected in the basin of the Cris rivers (White Cris and Black Cris) in West Romania. The concentrations in water were in the range: 1-15 pg Lr1 (Cu), 10-1500 pg L-1 (Mn), 3-100 pg L-1 (Zn). Metal contents, as dry mass fractions, w^m x IO6, were: 5-380 (Cu), 225-2000 (Mn), 23-1140 (Zn) in sediment; 1-11 (Cu), 4-40 (Mn), 8-130 (Zn) in fish fillet, and 5-34 (Cu), 100-600 (Mn) and 50-130 (Zn) in mollusc muscles with higher values for the White Cris samples. Among the seven sample collection sites only one was identified as having concentrations of Mn and Zn in water higher than the admitted levels, but the limits of tolerance for aquatic organisms were not exceeded in either river. In mollusc gills, the metal contents expressed as wdm x IO6 were: 8-60 (Cu), 11000-16000 (Mn), 190-1200 (Zn), and similar for both rivers in the case of Mn