Concentrations of chromium and copper in the ground water and drinking water distribution network of Birjand, 2009-2010

In areas with low amounts of rainfall such as Iran, it is very important to avoid contamination of groundwater resources. One of the major causes of water pollution is excessive amounts of heavy metals that may induce various diseases and even cancer. This study was aimed to determine the concentrations of chromium and copper in the in the ground water and drinking water network of Birnajd in 2009-2010. In this descriptive study, a census sampling of drinking water wells (28 samples) and distribution network (39 samples) of Birjand was preformed. The samples were analyzed by an atomic absorption apparatus and standard method. Data analysis was done by means of SPSS (version 15) at the significant level of P<0.05. The mean amount of copper in the samples of well and distribution network was 0.0046 ± 0.87 and zero, and chromium was 0.0916 ± 0.12 and 0.0514 ± 0.02 mg/L, respectively. Based on Standard NO 1053 of ISIRI regarding the specification of drinking water, the amount of copper in all samples were in desirable range (<0.05 mg/L). Chromium level was desirable only in 2 samples (7.1%) of the wells (0 mg/L), 19 samples (67.9%) of wells and 20 samples (51.3%) of the distribution network of the city were unallowable regarding the chromium level (>0.05 mg/L). Despite the normal level of copper, chromium contamination of drinking water in Birjand is dangerous. Regarding the environmental conditions, this contamination is likely to have geological origin that needs further studies and strategies to eliminate it.