title: Biological cycles for toxic elements in the environment.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001151:Arsenic / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001711:Biotransformation; D003035:Cobalt / Q000378:metabolism; D004463:Ecology; D004787:Environmental Pollution; D008628:Mercury / Q000378:metabolism; D008670:Metals / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D008745:Methylation; D008767:Methylmercury Compounds / Q000378:metabolism
chemical_list: D008670:Metals; D008767:Methylmercury Compounds; D003035:Cobalt; D008628:Mercury; D001151:Arsenic; D008697:Methane