Abstract: “Toxic elements like heavy metals are natural constituents of the earth’s crust and a number of these elements are biologically essential at trace levels and play an important role in human health. Arsenic is a ubiquitous element in the environment, which is found in trace amounts in rocks, water, soils, and plants and even in air. It is concentrated in many ore deposit types, and may cause environmental hazards due to unwanted delivery of this element and other associated elements (Zn, Ni, Mn and Sb) in the environment. Talvar river basin located in NW Iran, is a significant mineralized zone and the most famous and important As-Au mine in Iran is located here. This paper attempts to document the concentration of arsenic in surface waters. Water samples collected from Talvar stream indicate high content of as which ranges from 0.001 to 0.286 mg/l- 1 in water samples. The anomalously high background of trace metals in the area and its exposure to weathering is considered to be the main s”

Keywords: Heavy metals, Arsenic, Talvar River, Kurdestan Province, Iran