Natural environmental pollutions are blamed for some human health problems in western Iran. In order to clarify possible role of heavy metals on making these problems; various samples from soil, water and air particulate matters were obtained and concentration of heavy metals including arsenic and mercury more than standard levels were found among some them. Particularly, high levels of natural mercury concentration were found in soil samples from watershed of Gheshlagh dam while natural arsenic pollutions were traced in soil and water samples from Ghorveh. Additionally, arsenic pollution was found in dustfall particles sampled in Sanandaj city, capital of Kurdistan province. According to the results, geological formations in the region are recognized as sources of such pollutions in the study area.
