Occurrence, Formation and Fate of Organoantimony Compounds in Marine and Terrestrial Environments

Antimony is a relatively common group 15 metalloid, with world industrial production around 80000 tonnes. It occurs at 0.2 ppm crustal abundance (arsenic at 1.8 ppm, Carmalt and Norman 1997). The majority of antimony metal usage is in metallurgy where it is used as an alloy to impart hardness to lead and other metals (Maeda 1994). The main use of antimony compounds is as a flame retardant, with Sb203 being the most commonly used compound (ca. 90% of the annual usage of Sb203 in the US and Japan is as a flame retardant (Maeda 1994). The ubiquitous nature of such compounds in consumer products can lead to worrying amounts of antimony in landfill sites and in emissions from municipal incinerators. Organometallic antimony compounds — unlike those of As, Sn and Pb — are not exposed to the natural environment during usage. The only common use of organometallic antimony compounds is as precursors in the manufacture of semiconductors. This use is restricted to very controlled environments, hence there is no obvious route for organometallic antimony compounds to enter the environment. Anthropogenic emissions of antimony to the atmosphere have been calculated at 6 tonnes per year, while that for arsenic is 31 tonnes; natural emissions are 3 and 12 tonnes respectively.