The Occurrence of <i>Thiobacillus ferrooxidans</i> and Arsenic in Subarctic Streams Affected by Gold-Mine Drainage
DOI:
https://doi.org/10.14430/arctic2344Keywords:
Arsenic, Composition, Environmental impacts, Gold, Heterotrophic bacteria, Mining, Rivers, Suspended solids, Water quality, Alaska, Central, Tanana River region, YukonAbstract
Thirty-five streams in gold-mining regions between Rampart, Alaska, and Dawson City, Yukon Territory, were sampled to determine dissolved arsenic concentrations, and numbers of the acidophilic iron- and sulfur-oxidizing bacterium Thiobacillus ferrooidans. The pH of the streams varied from 6.3 to 8.6 and the streams were nearly saturated with dissolved oxygen. T. ferrooxidans was found in eight of nine streams affected by gold-mine drainage and in only one of 26 streams not affected by gold-mine drainage. Some of the streams affected by gold-mine drainage near Fairbanks, Alaska, occasionally contained levels of dissolved arsenic above 50 parts per billion. The recognition that T. ferrooxidans is associated with gold-mine material and that the heavy metal arsenic exists in streams affected by gold-mine wastes is important for understanding the environmental affects of mining activity on subarctic streams.
Key words: arsenic, gold mines, heavy metals, pyrite, Thiobacillus ferrooxidans
