Arsenic is acutely toxic and a highly potent carcinogen, but is widespread in the earth's crust and easily taken up and accumulated in crops. Contaminated water is the main source of arsenic poisoning, followed by ingestion of arsenic-rich food, especially rice that has been irrigated with arsenic-contaminated water. According to the WHO, arsenic has been found approaching or above guideline limits in drinking water in Argentina, Australia, Bangladesh, Chile, China, Hungary, India, Mexico, Peru, Thailand, and the US.
Amid recent reports of dangerous levels of arsenic being found in some baby rice products, scientists have found a protein in plants that could help to reduce the toxic content of crops grown in environments with high levels of this poisonous metal. A team of Scandinavian researchers has revealed a set of plant proteins that channel arsenic in and out of cells.