Arsenic, antimony and bismuth, three related elements of group 15, are all found in trace quantities in nature and have interesting biological properties and uses. While arsenic is most well known as a poison – and indeed the contamination of groundwater by arsenic is becoming a major health problem in Asia – it also has uses for the treatment of blood cancer and has long been used in traditional chinese medicine. Antimony and bismuth compounds are used in the clinic for the treatment of...