Abstarct: Historic mine and mining process in the mesothermal gold deposits of the Torghabeh gold field , generate extremely high sedimented As concentrations ( up to 39 ppm ) . This deposits are located at the ~ 8 km west of Mashhad and ~ 3 km north of Torghabe . In ~ 3 km distance from Torghabe a sidetrack branched from Mashhad_ Torghabe road . this way after ~ 4 km arrived to mine area . Orogenic gold deposits are typically strongly enriched in arsenopyrite and arsenian pyrite .( Goldfarb, 2005 ) with respect of this , it is clear that high As concentration is related to this gold deposit , for investigating about probable pollution at first place wee calculated the pollution index by just 9 sample for stream sediment which taken by geological survey of Iran ( in this case we calculated the Cd,Cf,Igeo and PLI ) . then we take our sample , locations were selected to investigate the behavior of As immediately after entering the sedimentary environment , as well as the spatial scale of As attenuation also we take the water sample in same place . all samples are analyzed with AAS method . In stream sediment As is changed between 2.87 to 23.15 ppm which higher than EPA 2004 standard for industrial zone (1.6 ppm) then this area has polluted sediment . also biogeochemical sample which taken from this area has shown the polluted area. For XRD analyzes in study area we chose 4 sample of our 12 samples , which 2 of them is for Band Golestan and 2 of them is for mine zone ( this place today is a part of Torghabeh city ). This experiment show us the major phase for any place which has much As concentration is Carbonate and Qurtze .