Microbial arsenic reduction in polluted and unpolluted soils from Attica, Greece

► Microbial reduction of As(V) was observed in soils from Attica, Greece. ► All reduced As was released to the aqueous phase. ► Microbial As reducing potential was not related with pre-existing contamination. ► Simultaneous reduction of Fe(III) also occurred. ► Reduced iron was bound in solid compounds.