Record Display for the EPA National Library Catalog


Main Title Ammonia Toxicity to Fishes. Effect of pH on the Toxicity of the Un-ionized Ammonia Species.
Author Thurston, Robert V. ; Russo, Rosemarie C. ; Vinogradov, German A. ;
CORP Author Montana State Univ., Bozeman. Fisheries Bioassay Lab.;Environmental Research Lab.-Duluth, MN.
Year Published 1981
Report Number EPA-600/J-81-550;
Stock Number PB82-207820
Additional Subjects Toxicology ; Fishes ; Ammonia ; pH ; Water quality ; Bioassay ; Reprints ; Salmo gairdneri ; Rainbow trout ; Fathead minnows ; Pimephales promelas ; Toxic substances
Library Call Number Additional Info Location Last
NTIS  PB82-207820 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 6p
United States and European water quality criteria to protect aquatic life assume that the toxicity of aqueous ammonia is attributable to the un-ionized (NH3) chemical species, and that the ionized (NH4+) species is nontoxic or significantly less toxic than NH3. Data are presented here on the toxicity of ammonia to rainbow trout (Salmo gairdneri) and to fathead minnows (Pimephales promelas) from two series of 96-h flow-through toxicity tests in which pH was controlled within the range 6.5-9.0. Results show that the toxicity of ammonia in terms of NH3 increased at lower pH values. It is concluded that NH4+ exerts some measure of toxicity and/or that increased H+ concentration increases the toxicity of NH3. It is recommended that water quality criteria be revised to consider the pH dependence of the toxicity of ammonia.