Antimony in the environment: knowns and unknowns

Abstract

Environmental context. Antimony first attracted public attention in the mid-1990s amid claims that it was involved in Sudden Infant Death Syndrome. A substantial number of papers have now been published on the element and its behaviour in the natural environment. However, many key aspects of the environmental chemistry of antimony remain poorly understood. These include critical areas such as its ecotoxicology, its global cycling through different environmental compartments, and what chemical form it takes in different environments. More focussed research would help the situation. The present review highlights several areas of environmental antimony chemistry that urgently need to be addressed.Abstract. The objective of the present article is to present a critical overview of issues related to the current state of knowledge on the behaviour of antimony in the environment. It makes no attempt to systematically review all published data. However, it does provide a list of the main published reviews on antimony and identifies subjects where systematic reviews are needed. Areas where our knowledge is strong -and the corresponding gaps -in subjects ranging from total concentrations and speciation in the various environmental compartments, to ecotoxicity, to cycling between compartments, are discussed, along with the underlying research. Determining total antimony no longer poses a problem for most environmental samples but speciation measurements remain challenging throughout the process, from sampling to analysis. This means that the analytical tools still need to be improved but experience shows that, to be useful in practice, this should be directly driven by the requirements of laboratory and field measurements. Many different issues can be identified where further research is required, both in the laboratory and in the field, the most urgently needed studies probably being: (i) long-term spatial and temporal studies in the different environmental compartments in order to collect the data needed to establish a global biogeochemical cycle; (ii) laboratory studies of antimony interactions with potential natural binders; (iii) reliable ecotoxicological studies. Montserrat Filella is a chemist and teaches Environmental Chemistry at the University of Geneva, Switzerland. Her main research interests focus on the understanding of the physicochemical processes regulating the behaviour of chemical components in environmental and biological compartments, mainly by combining computer modelling with field and laboratory measurements. The three main axes of her research concern the study of: colloids in natural waters, natural organic matter (quantification and interaction with trace elements) and Group 15 elements. She is also interested in other topics

Distribution, speciation and availability of antimony (Sb) in soils and terrestrial plants from an active Sb mining area

“…Worldwide, Sb is the ninth most mined metal and its compounds are listed as priority pollutant by the US Environment Protection Agency (USEPA, 1979). In soils Sb concentrations may be high, due to improperly disposed mine tailings and waste rocks (Filella et al, 2009a(Filella et al, , 2009cWilson et al, 2010), often by far exceeding reported background values for soils (Filella et al, 2002a;Reimann et al, 2010). Despite high total concentrations, the mobility and bioavailability of Sb is generally low (Casado et al, 2007;Flynn et al, 2003).…”

“…In general, inorganic Sb compounds were found to be more toxic than organic ones, with Sb(III) more toxic than Sb(V) species (Filella et al, 2002b). In soil solution Sb is mainly present as pentavalent oxyanion, Sb(OH) 6 À (Filella et al, 2009c;Oorts et al, 2008). This is also the dominant form observed in contaminated soils near smelters and at shooting ranges Takaoka et al, 2005).…”

“…Based on the key features in the XANES regions shown in Fig. 1 (marked with arrows), the presence of Sb 2 O 3 could be excluded, and Sb 2 O 5 does not occur naturally in the environment (Filella et al, 2009c …”

Influence of iron plaque and cultivars on antimony uptake by and translocation in rice (Oryza sativa L.) seedlings exposed to Sb(III) or Sb(V)

“…methylated species)<antimo-nates (Sb(V))<antimonites (Sb(III) (Gebel 1997;He and Yang 1999;Krachler et al 2001;Filella et al 2002), which is similar to arsenic (As) (Susan et al 2010). Since inorganic Sb species are more abundant than organic species in the natural systems (Filella et al 2009), Sb(V) and Sb(III) were used in our experiments. As a waterlogged plant, rice is usually cultivated in an anaerobic and chemically reduced environment (Colmer 2003 (Armstrong 1967).…”

Antimony in the environment - the new global puzzle

“…Review articles Filella et al [13] in their Review discuss the environmental chemistry of Sb, calling for more focussed research, particularly in the areas of ecotoxicology and speciation analysis.They ask that researchers carefully read the primary literature as myths about Sb are being propagated. A further Review from Tschan et al [14] highlights that, although available soil Sb is readily taken up by plants, little is known about the mechanism by which this occurs.…”