Survey on the Geo-statistical Distribution of Heavy Metals Concentration in Sistan and Baluchistan’s Groundwater via Geographic Information System, Iran

Abstract Background and purpose:The rapid urbanization and industrialization in many parts of the world have led to the accumulation of heavy metals in the terrestrial environment and pose a serious threat to human health. In this study, a broad assessment was conducted to estimate the levels of heavy metals in groundwater in Sistan and Baluchestan via geographic information system (GIS), Iran, geo-statistical distribution of these contaminants was delineated in affected areas. Materials and Methods:In this study, a total of 357 water samples were collected from designated wells in the area and transported to laboratory according to standard methods. The levels of heavy metals including chromium, cadmium (Cd), lead (Pb), and aluminum were measured by atomic absorption spectrometry. The findings were compared with the Standard values recommended by the Institute of Standards and Industrial Research of Iran, United States Environmental Protection Agency and World Health Organizations. Moreover, employing GIS software, the geo-statistical distribution of heavy metals concentration in groundwater in Sistan and Baluchestan was revealed. Results:In the whole samples, the concentrations of two elements, Pb and Cd, were 31.9% and 40.3%, respectively, which were higher than the maximum permissible limits. The rest of the study variables showed to be within the standards/guidelines recommended by international organizations. Conclusion:Heavy metal levels in groundwater of most study areas were compatible with advised international criteria that indicate a very slight influence of industrialization in the area. Relatively high concentrations of Pb and Cd in few locations suggest the state authorities to give more attentions in developing plans, and consider sustainable development in the area.