Assessment of water pollution and suitability to fish life in six Italian rivers.

This paper reports the results of a monitoring programme of six rivers (Serchio, Cecina, Cascina, ERa, Elsa and Pavone) that drain north-west Tuscany (Italy). In this area, agricultural, industrial and urbanization pressures affect water quality, also in terms of suitability for the survival of aquatic organisms. The river waters were monitored for several physico-chemical parameters (temperature, dissolved oxygen, suspended solids, total ammonia, nitrites, Cu, Cd, Cr, Ni and Pb) in order to assess the anthropogenic impact on the environmental conditions of these watercourses and their suitability for fish life. Statistical data handling was performed for each river and the percentage of physico-chemical parameters that, according to the E.C. law, were over the limits that must not be exceeded to protect fish life, was calculated and a classification was made of the six rivers in this sense. Concerning the metals, inter-element relationships (between chromium and nichel, lead and copper, nichel and lead and copper, copper and lead) were found which allow some remarks on the origins of the anthropogenic impacts, and comparisons were made with two metal-polluted watercourses in northern Italy, the Po and Lambro rivers. From the comparison, the Tuscan rivers showed generally lower metal contamination, especially with respect to the Lambro.