Role of Environmentally Relevant Chemical Mixtures on Stress Responses in Daphnia magna (Water Flea)
William S. Baldwin
Environmental Toxicology (College of Agriculture, Forestry and Life Sciences)
Daphnia magna is a popularly studied model organism in environmental toxicology. The fates of several individual chemical contaminants have been well investigated in the ecosystem and different animal species. However it is challenging to understand or predict the potential effects of chemicals when they are in a mixture. My research investigates into the synergistic and independent effects of certain chemical mixtures on the responsiveness of a freshwater model organism. We are looking into the molecular mechanisms that alter toxicity of relevant environmental toxicants such as atrazine (herbicide), pyriproxyfen (JHA insecticide) and triclosan (consumer product antibiotic). We have recently found that atrazine can induce detoxicification enzymes in Daphnia and provide protection from other toxicants such as triclosan, when exposed in mixtures. The research will also focus on understanding the crucial role of diet in rendering an organism less or more sensitive to ecological stressors. Increased knowledge of how chemicals interact as mixtures will help us to better use scientific data to develop reasonable solutions for regulating chemical mixtures and managing land and water resources that are contaminated or relatively “clean”.