The content of selected heavy metals and their bioavailable fraction in sediments of Solina Reservoir (Poland)

Research on sediments of Solina Reservoir, Poland, were characterized by a content of copper higher than other heavy metals (Cr, Ni, Cd and Zn). The strongest correlations between pairs of heavy metals were Zn–Cu and Ni–Cr, were revealed while there was also a correlation between total contents of chromium and nickel, and between pH value and sediment percentage of organic matter. The content of copper at levels exceeding the geochemical background (more than 20–fold), sediments could only by classified as of the 3rd purity class (according to the PIG criterion) or the 5th purity class (according to Müller’s classification). Ecotoxicological criteria indicate that levels of chromium, copper, nickel and cadmium are all high enough to affect aquatic life. However, the heavy metals analyzed differ in their mobility and bioavailability. The highest percentage value for the ion–exchangeable fraction was noted for cadmium, the lowest for chromium. This means that sediments have a greater capacity to release cadmium into the water column, with the consequence being secondary pollution source for the aquatic ecosystem