Investigation of Heavy Metals (Cd, Cr, Ni, Pb, Zn) in Islamshahr Groundwater Resources and their Regional Distribution Pattern in GIS

Nowadays, pollution of groundwater by heavy metals is encreasing. Heavy metals are one of the most widespread cause of pollution in water and the presence of increasing levels of these metals in the environment is causing serious concern in public opinion owing to their toxicity.
This study aims to assess the concentration and distribution pattern of heavy metals (Cadmium, Chrome, Nickel, Lead and Zink) in groundwater of an industrialized region in Eslamshahr which located in the southeastern of Tehran
Presently, groundwater is the predominant source of drinking water in this town. For this purpose, 92 samples were taken from 23 wells in 4 seasons.The concentration of heavy metals in the samples was measured by flame atomic absorption spectrophotometry. ARC GIS software was applied for preparing the distribution patterns.
The results showed that chrome and zinc concentrations were lower than the permissible level in the drinking water. However, the concentration of cadmium in 8.7% of samples taken in winter were higher than the permissible level determined in drinking water standard of Iran. Nickel concentration in winter was 8.7% higher than the permissible level. Lead concentration of samples in 47.8% and 4.35% of samples taken in summer and winter were higher than the permissible level, respectively. The high level of water pollution in southern part of Eslamshahr is attributed to the large number of industries, big farm lands, application of chemical fertilizers and the pesticides containing heavy metals, busy main and secondary roads , and most importantly, the hydraulic slope from northwest to southeast of this region.