Arsenic is well-known for its intentional use as a poison. Fans of the 1944 comedy film Arsenic and Old Lace may remember that the Brewster sisters used it in their homemade elderberry wine to murder lonely old men. But arsenic also occurs naturally in various foods, such as rice, because it is found naturally in the environment. Arsenic is an odorless and tasteless element that enters water and crops from natural deposits in the earth as well as from agricultural and industrial practices, inclu…