Rainbow trout were exposed to a range of silver concentrations (as AgNO3) in flowing synthetic soft water (0.05 mM Na+, 0.05 mM Cl-, 0.05 mM Ca2+, 0.02 mM Mg2+, 0.02 mM K+, pH 7.0, approximately 0.7 mg C/L dissolved organic carbon, 10 mg CaCO3/L, 10 ± 2°C) to investigate a possible relationship between short-term gill silver accumulation (3 h or 24 h) and acute silver toxicity (96-h mortality). We also investigated potential relationships between gill silver accumulation and inhibition of Na+ uptake plus inhibition of gill Na+K+-adenosine triphosphatase (ATPase) activity. The 96-h median lethal concentration (LC50) values were 13.3 μg total Ag L-1 and 3.3 μg dissolved Ag L-1. A relationship was demonstrated between 3-h and 24-h gill silver accumulation and 96-h mortality. A relationship also was demonstrated between gill silver accumulation and inhibition of Na+ uptake at 24 h of exposure. No relationship between gill silver accumulation and inhibition of gill Na +K+-ATPase activity was found. The 96-h median lethal gill accumulation (LA50) values of 129 (at 3 h) and 191 ng g-1 (at 24 h) and a conditional equilibrium binding constant of 8.0 for Ag+ binding to the gills were calculated. These observations support use of the silver biotic ligand model (BLM) as a regulatory tool to predict acute silver toxicity.
- Adenosine triphosphatase activity
- Sodium uptake
- Water quality criteria
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Health, Toxicology and Mutagenesis