Distribution of heavy metals in the Mala Welna River system (western Poland)

This paper reports the results of measurements of heavy metal concentrations in water, suspension, and bottom sediment samples collected at eight sites along the Mala Welna River (western Poland). The samples were collected once a month from May to August 2006. The highest variations in the water of the Mala Welna River were noted in the concentrations of Zn, Pb, and Cu. The results indicate that the suspension plays an important role in the transportation of pollutants contaminating the water and later in the accumulation of pollutants in the bottom sediments. The concentration of heavy metals in the bottom sediments were determined individually in grain size fractions: > 2, 2-1, 1-0.5, 0.5-0.25, 0.25-0.1, 0.1-0.063, <0.063 mm. Concentrations of them were the lowest in the 0.5-0.25 and 0.25-0.1 mm fractions, and were the highest in the 0.1-0.063 and <0.063 fractions.