This book evaluates the risks to human health and the environment posed by arsenic and arsenic compounds. Arsenic is widely distributed in the earth's crust and is emitted into the atmosphere by coal-fired power generation plants and volcanic activity. Inorganic arsenic of geological origin is found in groundwater, which is used as drinking-water in several parts of the world, e.g. Bangladesh. In these areas, drinking-water is the main source of arsenic intake, but elsewhere food is the principal source.