Investigation of Pb and Cd concentrations in drinking water samples of Gorgan water supply network: preparation of zoning maps by geographic information system

With the expansion of urbanization and the development of industry, environmental pollution, including sources of drinking water to heavy metals, has become a global problem. Therefore, the present study was conducted to measure the concentration of lead and cadmium in the water of Gorgan distribution network.

This is a descriptive cross-sectional study in which the concentrations of heavy metals lead and cadmium were measured in 25 different stations of the Gorgan drinking water distribution network from April to September 2018 by atomic absorption device. Statistical analysis was used from SPSS ver 22 software. Also, zoning maps based on the concentration of these two metals were prepared by Geographic Information System (GIS) software.

The results of measuring the lead and cadmium concentration showed that all measured values are less than national and international standards. In general, the average concentrations of lead and cadmium were 4.38 and 0.1 μg/L, respectively. The results of Kruskal-Wallis test showed that there was a significant difference (p <0.01) between the concentrations obtained from lead metal in different months. Additionally, the distribution map of this lead and cadmium exhibited that in the central areas and some border areas, the concentration of these two metals is higher.

According to the obtained results, it can be seen that the concentration of heavy metals lead and cadmium in the water of Gorgan distribution network is within the permitted standards.