Research in Environmental Toxicology
Belden Laboratory
Department of Zoology
Oklahoma State University
Effects of Pesticides in Wetlands and Related Upland Habitat
Depressional wetlands and other temporary aquatic habitat is commonly embedded within the agricultural landscape. Organisms utilizing this habitat such as aquatic invertebrates and amphibians are at risk for pesticide exposure. Additionally, terrestrial amphibians emerging from these wetlands may be exposed to pesticides within the agricultural field. Our recent research has indicated that aerial applied pesticides pose an environmental hazard to both aquatic and terrestrial amphibians. We are continuing efforts to ascertain the actual ecological risk that is posed. Collaborators: McMurry and Smith, Zoology, Oklahoma State University
Integrative Passive Sampling
Passive sampling devices are promising tools that allow for continuous monitoring of aquatic environments without the difficulties of collecting, transporting, storing and analyzing numerous large sample volumes. Our interest is in further developing passive samplers that can integrate the environmental concentration of contaminants over time and in relating these time-weighted concentrations to toxicity. Current projects include investigating the use of POCIS samplers for measurement of explosives and modifying current integrative passive sample designs to better measure pulsed exposures (96h or less) of hydrophobic pesticides and trace metals.
Evolutionary Toxicology
Studies in evolutionary toxicology have frequently demonstrated the potential for contaminants to act as strong sources of selection in both target and non-target organisms. However, evolutionary change in aquatic organisms has also occurred as a result of anthropogenic stress not directly related to exposure to pesticides and organic contaminants. We are interested how these changes influence an organism's susceptability to chemical contaminants. In addition, we are also interested in how evolutionary changes, which occured as a result of natural stressors, influence the susceptability to novel, anthropogenic chemical contaminants. Collaborator: Jeyasingh, Zoology, Oklahoma State University
Urban Environmental Contaminants
Organic contaminants such as pesticides and PAHs are frequently encountered in the urban environment and may be a hazard to human and ecological health. Our current project is investigating if PAHs in rooftop runoff accumulate in soil and an plants after irrigation. Collaborator: Vogel, Biosystems and Agricultural Engineering, Oklahoma State University
Urban Environmental Contaminants
Organic contaminants such as pesticides and PAHs are frequently encountered in the urban environment and may be a hazard to human and ecological health. Our current project is investigating if PAHs in rooftop runoff accumulate in soil and an plants after irrigation. Collaborator: Vogel, Biosystems and Agricultural Engineering, Oklahoma State University
Toxicity of Mixtures
The most common environmental exposure scenario is to be exposed to a mixture of contaminants. Our goal is to better understand and predict the toxicity of mixtures. We are particular interested in how to predict mixture toxicity from the toxicity of individual contaminants and in situations where a contaminant potentiates other contaminant resulting in geater toxicity than would be expected.