Gallium in freshwater and marine water
Toxicant default guideline values for protecting aquatic ecosystems
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
Gallium is a Group IIIb heavy metal, in the same group in the Periodic Table as aluminium. As for aluminium, gallium is an amphoteric metal and occurs in the Ga3+ state (in acid solution) or as complex gallate ions or hydroxylated anions or complexes (Cotton & Wilkinson 1983). The current analytical practical quantitation limit (PQL) for gallium is 0.01 µg/L in fresh water and 0.3 µg/L in marine water (NSW EPA 2000).
There were only three data points on two fish species. None met the selection requirements but the figures were: Oncorhynchus mykiss, 28-day LC50, 3510 µg/L; Cyprinus carpio, 3 d no end-point recorded, 2400 to 17,000 µg/L.
As data did not satisfy selection requirements, only a freshwater environmental concern level (ECL) (refer to Section 184.108.40.206 of the ANZECC & ARMCANZ 2000 guidelines) of 18 µg/L could be derived using an assessment factor (AF) of 200 on the single chronic data. This could be used as a marine low reliability trigger value for gallium. This figure should only be used as an indicative interim working level. No marine data were available.
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.
Cotton FA & Wilkinson FRS 1983. Advanced inorganic chemistry. Wiley Interscience, New York.
NSW EPA 2000. Analytical Chemistry Section, Table of Trigger Values 20 March 2000, LD33/11, Lidcombe, NSW.