COMBINED EFFECTS BETWEEN ATRAZINE, COPPER AND PH, ON TARGET AND NONTARGET SPECIES

Binary mixtures of atrazine (herbicide) and copper were studied in three microorganisms: a bacterium, a protozoan and a microalga. Factorial experiments were carried out to detect interactive effects and toxicity results were interpreted with multiple regression analysis. The levels of concentrations tested on algae were close to those found in aquatic environments. This study confirms the specific toxicity of atrazine to photosynthetic cells and the broad activity spectrum of copper which is toxic to the three species tested. No significant interactions were found between atrazine (up to 100μg/1) and copper (up to 25 μg/l Cu2+) on algae. No interactive effects were registered on protozoans either. A synergistic effect does occur on bacteria but at such concentrations (10mg/1) that this effect is not considered ecologically meaningful. © 1990.