Water quality fact sheet: Arsenic

Arsenic is a trace element found at variable concentrations in the atmosphere, soils and rocks, natural waters and organisms. It is mobilised in the environment through a combination of natural processes such as weathering reactions, biological activity and volcanic emissions as well as through a range of human activities, including mining, industry and agricultural use of arsenical pesticides. Of the various sources of arsenic in the environment, drinking water poses potentially the greatest threat to human health.