study concentrations changes of lead, chromium, nickel, cadmium, zinc and copper in beshar river of kohgiluyeh and boyerahmad province, iran

due to the lack of water quality of resourses in country, exact review of available water resources quality, especially in terms of heavy elements (heavy metals) has a particular importance. due to industrial towns 1 and 2 of yasuj city and also yasuj wastewater treatment, surveying environmental harmful effects of heavy metals on this river is very important. to investigate the changes of heavy metals (pb, cr, ni, cd, zn and pb) sampling from three stations qalat, mokhtar and pataveh was carried out from september 2012 until may 2013 along the beshar river. to estimate the severity of the pollution, pi index (pollutant index) and cumulative index ipi and mcd were used. mean values ​​of the elements shows that the maximum and minimum mean value of the elements respectively is related to chromium and cadmium.calculating of pollution index (pi) and then cumulative index ipi and mcd based on the epa,who, nas and fao standards, shows the low pollution for the whole data in water of  beshar river. the process of elements concentration changes primarily is related to distance between sampling points and sources of pollutants. being far or near is the important point about this issue. just when the 1053 standard is used for computing the ipi and mcd indices, these indices are different in contamination degree. in this situation one of the indices is placed in low pollution class and another index will be in very high pollution class.