EN
Aquatic ecosystems are exposed to constant human pressure. The concentrations and species in which heavy metals occur are the basis for assessing the threats from secondary contamination of waters due to their toxicity, bioavailability, possible migration, accumulation, and biomagnification. Samples of soils, bottom sediment, and water were collected from a number of rivers in southern Świętokrzyskie province (Kielce region, Poland) that flow through areas with different types of land use. Tessier's sequential extraction technique was used, assisted with microwave radiation and ultrasound. The levels of Zn, Cd, and Pb in the various extracts were determined using F-AAS and GF-AAS.