Precautions in the use of 110m Ag as a tracer of silver metabolism in ecotoxicology: Preferential bioconcentration of 109 Cd by trout gills after 110m Ag exposure

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Hansen, Heinz J. M., Grosell, Martin, Jacobsen, Ulf, Jørgensen, Jesper C., Hogstrand, Christer, Wood, Christopher M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2002
• Subjects: European eel
• Online Access: http://dx.doi.org/10.1002/etc.5620210516; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fetc.5620210516; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.5620210516

Abstract An often overlooked problem in the use of radiotracers is the possibility of isotopic contamination. Commercially available silver 110m Ag was used to study silver uptake and depuration in rainbow trout and European eel. Quality control by means of comparative γ and β counting brought our attention to a contamination of the 110m Ag stock with 109 Cd, which could be seen only because the 109 Cd was markedly bioconcentrated by trout gills. The contamination could not be detected in eel gills or in other tissues of both species. The difference between trout and eel gill structure and function is the probable explanation for the marked difference in 109 Cd accumulation. This contamination was identified as 109 Cd by γ spectroscopy and its origin by transmutation of natural silver as a result of neutron activation is described. Failure to recognize this contamination problem would have resulted in serious misinterpretation of the data set. Guidance for avoiding this problem is given.