Assessing heavy metal bioavailability and ecological risks in river sediments: A case study of the Dłubnia River, Poland

The D & lstrok;ubnia River plays a vital role in the water supply for the residents of Krako<acute accent>w. The Geoaccumulation Index (Igeo), Pollution Load Index (PLI), Environmental Risk Factor (ERF) and the forms of heavy metals (HMs) were used to assess the environmental hazard of HMs in the bottom sediments (BS) of the D & lstrok;ubnia River. Total concentrations of HMs were determined in BS collected at Imbramowice, Grzegorzowice Wielkie, Iwanowice, Podskale, Micha & lstrok;owice, M & lstrok;odziejowice and Raciborowice: Cd (0.00-0.825 mg center dot kg- 1d.m); Cu (0.00-36.057 mg center dot kg- 1d.m), Cr (3.04-18.145 mg center dot kg- 1d.m), Ni (2.002-12.141 mg center dot kg- 1d.m), Pb (2.326-46.489 mg center dot kg- 1d.m) and Zn (21,659-489.49 mg center dot kg- 1d.m). The highest concentrations of the HMs were found in Imbramowice. Igeo values ranging from - 3.8-2.8 revealed that the BSs are not polluted only in Grzegorzowice Wielkie. The PLI revealed that the BSs in Imbramowice are polluted with HMs (1.8-3.5). ERF values ranging from 0.00 to 0.40 showed a low risk of HMs contamination throughout the length of the D & lstrok;ubnia River. The results of the speciation of HMs analysis indicated that the dominant form of HMs in the BSs was the immobile form, that is, bound to silicates. The results confirmed that surveying watercourses that are Level 2 river catchments and drain into main rivers is justified.