An IndexApproach toMetallic Pollution in RiverWaters

Abstract

Twenty water samples from a river system in southern Caspian Sea basin werecollected and analyzed for physicochemical parameters and metals (Cu, Zn, As, Cd, Pb, Ni andMn). In order to evaluate the risk potential of metal pollution in river water, use of two indicesnamely heavy metal pollution index (HPI) and contamination index (Cd) accompanied by clusteranalysis was taken in to consideration. Stations located within the upstream of the river (1 to 13)seemed to encounter low risk potentials while the downstream stations (14 to 20) approved tohold higher risks.The results also showed relativelymeaningful correlation among different metalswhich may be attributed to their same entry source, mainlymining and quarrying activities in thecentral parts of the basin following bymunicipal and industrial wastewater discharge to the riverin downstream. The convergence of both indices in this study was also of interest. Although themean values of both indices were below the critical values, severe precautions must be taken intoconsideration especially in the stations holding high risk potentials. Extreme use of river waterfor drinking, agriculture and industrial purposes within the water basin, relatively biota-richcharacteristic of the river and Caspian Sea as the final sink of the river are among the most significantreasons that make the river monitoring implementation inevitable.