pH-Induced Changes in Blood Lead of Lead-Exposed Rainbow Trout (Salmo gairdneri)

Abstract
Blood of juvenile rainbow trout (S. gairdneri) exposed to Pb in water showed increasing Pb concentrations as pH of the test water decreased from 10.0 to 6.0. A decrease in pH by 1.0 unit from any reference pH resulted in an increase of blood Pb by a factor of 2.1. Since sublethal Pb toxicity is related to uptake, these results suggest that toxicity increases as pH decreases.. Control experiments indicated that reactions of Pb with inorganic constituents of the test water were complete within 3 h and that blood Pb was at equilibrium with water Pb within 48 h. At the time of blood sampling in the pH experiment, both Pb complexation processes in the exposure system, plus Pb uptake and release from the blood, were at equilibrium.