Arsenic bioaccessibility in gold mine tailings of Delita, Cuba

► Tailings pile with up to 35,372 mg As kg−1 are the main source of arsenic in Delita. ► Goethite and amorphous Fe arsenate are associated with maximum As bioaccessibility. ► The gastrointestinal As bioaccessibility is limited for arsenic in arsenopyrite and scorodite.