Evaluation of the content of heavy metals in Fluvisols of floodplain area depending on the type of land use

The aim of the research was the evaluation of the potential contamination with heavy metals in Fluvisols, used as grasslands and arable soils of Vistula River floodplain in the area of the Chełmiński and Nadwiślański Complex of Landscape Parks. The indicators proposed by Håkanson allow to evaluate the potential ecological risk of the contamination with heavy metals associated with the accumulation of one metal or a combination of multiple metals. The mean total content of Cd, Pb, Ni Cu, Zn, Mn, as well as Fe in Fluvisols at the depth of 120–150 cm was assumed as the content of the local geochemical background and it was: 1.0 mg·kg^-1, 22.8 mg·kg^-1, 26.9 mg·kg^-1, 1.4 mg·kg^-1, 60.8 mg·kg^-1, 591 mg·kg^-1, and 17.6 g·kg^-1, respectively. The values of the indicators such as contamination factor (CF), enrichment factor (EF) revealed higher levels of the accumulation of heavy metals in the soils of grasslands, which shows that the method of their use has a significant effect on the total metal content. Contamination with heavy metals in the surface layer of the investigated Fluvisols was found, and in terms of the content with cadmium a moderate and considerable potential ecological risk was reported. Due to the fact that no unfavourable effect of trace elements on the riverside environment was proved and that the floodplain areas are under agricultural use, to evaluate the contamination with metals, the limit values for the soils of agricultural land were assumed as stipulated in the Regulation of Minister of the Environment of September 9, 2002. According to that criterion, the soils studied do not qualify as contaminated with metals. Only in one of the soil sampling points the total content of zinc was higher than the one determined as the maximum for agricultural land soils, namely 350 mg·kg^-1. A significantly positive correlation was noted between the content of C org and the total content of metals as well as very numerous interactions between metals. The results of cluster analysis confirm that the method of use determines the concentration of metals in the surface layer of the Fluvisols studied.