This study measured dissolved metals in surface water around artisanal gold mining and ore processing at Marmato, Colombia. Gallium is discussed as detectable and as elevated in mining-affected water. The main text does not print a gallium concentration.
Key numbers
- The discussion states that gallium and indium were present at detectable levels and may come from sphalerite and marmatite, and later that gallium and indium concentrations were elevated (Discussion). No gallium value, unit, or sample count is printed in that discussion.
- Indium may be an artifact because ICP-MS used indium as an internal standard (Discussion). The paper does not say that about gallium.
- Dissolved metals were measured by ICP-MS (Agilent 7700x). The printed water table in the main text lists cobalt, nickel, copper, zinc, arsenic, cadmium, antimony, gold, mercury, and lead, not gallium (Table 3).
Methods (brief)
Water samples were filtered and acidified. Total dissolved metals were measured by ICP-MS. Arsenic species were separated on an ion-exchange cartridge. A field blank was processed with the samples.
Evidence fitness
Supports a qualitative statement that gallium was detected in these mining-affected waters and that the authors link it to zinc sulfide ore. Does not support a concentration, a detection frequency, or a health comparison.
Limitations
Gallium is a brief aside. The word elevated is the authors’ description. The main text does not give the baseline that word is measured against.
Related evidence
Update history
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