Author
 |
Griffin, Billy |
|
Submitted to: U.S. FDA Public Master File No. 5590
Publication Type: Popular Publication Publication Acceptance Date: 11/24/1997 Publication Date: N/A Citation: N/A Interpretive Summary: The factors which affect the toxicity of copper to fish that may come in contact with it in the environment are considered. There are naturally occurring factors such as binding of copper to clay particles or to organic material in the water, and living factors such as removal by microscopic lifeforms for biological use or storage. Characteristics of the water in which copper is found can influence its toxicity. The overall effect of these factors suggests that copper concentrations present as a result of the use of copper sulfate as a disease treatment do not pose a serious threat to the health of the animal being treated. Technical Abstract: Risk accompanies any disease treatment whether the treatment is simply moving fish to avoid a source of infection or is a chemical assault on waterborne pathogens. Success is realized when the treatment does less harm to the fish than to the pathogen. The perfect treatment would be one that eliminated absolutely every member of a pathogen population but was totally innocuous to the fish. Copper sulfate used as a disease treatment is not perfect yet it has been successfully used in fish production for many decades. The combination of biotic and abiotic factors such as adsorption and absorption of copper by phytoplankton, adsorption to soil particles and dissolved organic material, precipitation as insoluble inorganic copper complexes and the speciation restrictions exerted by pH above neutrality all act to reduce the total copper concentration and to limit the amount of free Cu++ present. Physiological changes caused by short-term exposure to waterborne copper (as in a single treatment episode) are transient and no permanent effects have ever been reported (except that the fish may be alive as a result of the treatment). |
