Antimony in freshwater and marine water
Toxicant default guideline values for protecting aquatic ecosystems
October 2000
Extracted from Section 8.3.7 ‘Detailed descriptions of chemicals’ of the ANZECC & ARMCANZ (2000) guidelines.
The default guideline values (previously known as ‘trigger values’) and associated information in this technical brief should be used in accordance with the detailed guidance provided in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.
Description of chemical
Two forms of antimony are found in natural water: antimony (III) occurs under moderately oxidising conditions, whereas antimony (V) predominates in highly oxidising environments (Callahan et al. 1979). Most of the toxicological studies are on antimony (III). Water-borne antimony can result from natural weathering of geological formations and minerals as well as from anthropogenic sources such as effluents from mining, manufacturing and municipal wastes (USEPA 1988b). There are no known biological functions of antimony (Wood & Wang 1985). There are few studies on the bioaccumulation of antimony in the aquatic environment. Chapman et al. (1986) reported bioconcentration factors of 40 and 16,000 for freshwater fish and invertebrates respectively, whereas no detectable bioconcentration of antimony was found in bluegill sunfish (Lepomis macrochirus) during 28 days exposure (USEPA 1978). The current analytical practical quantitation limit (PQL) for antimony is 0.05 µg/L in fresh water and 5 µg/L in marine waters (NSW EPA 2000).
Freshwater guideline
Most of the ecotoxicological data are for antimony (III), hence the trigger values are for Sb (III). There were 16 acute data points for antimony available on 5 taxonomic groups, comprising:
Fish: one species, Pimephales promelas, 96-hour LC50, 9000 to 12,000 µg/L.
Crustaceans: one species, Daphnia magna, 48 to 96-hour EC50 immobilisation 12,100 to 423,450 µg/L.
Annelids: one species, Tubifex tubifex, 48 to 96-hour LC50, 678,000 to 920,000 µg/L.
Ciliates: one species, Tetrahymena pyriformis, 36-hour IC50 (IC; incipient concentration) population growth, 6000 µg/L. This was screened out.
Algae: one species, Selenastrum capricornutum, 96-hour EC50 growth, 760 µg/L. This was screened out.
A freshwater low reliability trigger value of 9 µg/L was derived for antimony (III) from the fish figure using an assessment factor (AF) of 1000. This figure should only be used as an indicative interim working level. Collection of more data would assist in revision of this figure.
Marine guideline
Marine data for antimony were available for only two taxonomic groups and it was not possible to calculate a reliable guideline trigger value:
Fish: one species, Blennius pholis, 96-hour LC50, 534,000 µg/L.
Crustaceans: two species, 4 to 9-day LC50, 267,000 to 534,000 µg/L.
In the absence of sufficient marine data, a marine low reliability antimony (III) trigger value of 270 µg/L was derived using an AF of 1000, for use only as an indicative interim working level. Caution is advised, however, if the freshwater figure is exceeded because of the more limited marine data.
References
ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.
Callahan MA, Slimak MW, Gabel NW, May IP, Fowler CF, Freed JR, Jennings P, Durfee RL, Whitmore FC, Maestri B, Mabey WR, Holt BR & Gould C 1979. Water-related environmental fate of 129 priority pollutants, Vol 1. US Environmental Protection Agency, Washington DC. EPA-440/479-029a.
Chapman WH, Fischer HL & Pratt MW 1986. Concentration factors of chemical elements in edible aquatic organisms. Lawrence Radiation Laboratory, Livermore, California.
NSW EPA 2000. Analytical Chemistry Section, Table of Trigger Values 20 March 2000, LD33/11, Lidcombe, NSW.
USEPA 1978. In-depth studies in hand environmental impacts of selected water pollutants. US Environmental Protection Agency. Contract 68-01-4646.
USEPA 1988b. Ambient water quality criteria for antimony (III). US Environmental Protection Agency, Washington DC, 8/30/88 draft.
Wood JM & Wang HK 1985. Strategies for microbial resistance to heavy metals. In Chemical processes in lakes, ed W Stumm, John Wiley & Sons, New York, 81-98.