In this study we have worked on the evaluation of heavy metal contamination in the
sediments taken from the Tisza River and its tributaries, and thereby used the sequential
extraction method, geochemical normalization, the calculation of the enrichment factor
(EF), and the methods of statistical analysis. The chemical fractionation of Ni, Cu,
Zn, Cr, Pb, Fe, and Mn, carried out by using the modified Tessier method, points to
different substrates and binding mechanisms of Cu, Zn and Pb in sediments of the tributaries
and sediments of the Tisza River. The similarities in the distributions of Fe and
Ni in all types of sediments are the result of geochemical similarity as well as of
the fact that natural sources mainly affect the concentration levels of these elements.
The calculated enrichment factors (EF, measured metal vs. background concentrations)
indicated that metal contamination (Cu, Pb, Zn and Cr) was recorded in the sediments
of the Tisza River, while no indications of pollution were detected in the tributaries
of the Tisza River and the surrounding pools. The maximum values of the EF were close
to 6 for Cu and Pb (moderately severe enrichment) and close to 4.5 for Zn (indicating
moderate enrichment). It can be said that the Tisza River is slightly to moderately
severely polluted with Cu, Zn, and Pb, and minorly polluted with Cr. It is concluded
that sediments of the Tisza serve as a repository for heavy metal accumulation from
adjacent urban and industrial areas.