Arsenic in the geosphere--a review.

An attempt is made to quantify the global element cycle for arsenic, based on an extensive literature research with special emphasis on the most recent works. Reservoirs in and fluxes within and through lithosphere, atmosphere, pedosphere, hydrosphere, biosphere, and anthrosposphere are being presented. Crucial knowledge gaps are addressed and some simple model calculations partially question currently held ideas about sources, pathways, and the fate of arsenic in the environment.