Adjunct Professor Emeritus
I am an ecologist and ecotoxicologist with interests in the impact of human activities, particularly the release of toxic substances, on organisms at the individual, population, and community levels. I am most interested in applying basic ecological insights (e.g., feeding and digestive strategies, animal/substrate interactions) to toxicology in order to provide greater environmental realism to questions of pollutant uptake and toxicity. Most of my research falls within the general areas of pollutant bioavailability, bioaccumulation, and toxicity, and the extension of these principles to assessment of ecological risk posed by contaminated aquatic sediments. The current research in my laboratory is focused on the environmental toxicology of pesticides, and particularly those that are sediment-associated. Prominent among these are the pyrethroids, a class of insecticides widely used in both agricultural and urban environments. Our studies have shown the compounds to commonly be found in agricultural and urban waterways, and frequently present at concentrations acutely toxic to sensitive invertebrates. My lab is currently developing several new techniques to determine what substances may be responsible for toxicity when observed, including tools to help identify when pyrethroids are playing a role in this toxicity. We are quantifying pyrethroid input to surface waters from urban storm drains, and studying the seasonality and mechanism of transport. Finally, we are evaluating several approaches for mitigating off-site transport of sediment-bound pesticides from agricultural lands, such as the use of polyacrylamide to control erosion. Another area of my recent research is the development of a procedure to better quantify the bioavailable contaminant in sediment by extraction of the sediment using the digestive fluid of deposit-feeding invertebrates. Solubilization by this fluid, rather than an exotic chemical as would be used in a conventional extraction, has greater ecological relevance and provides a better basis for environmental management decisions. Other past projects in my laboratory include evaluation of dredging as a remedial alternative for a DDT-contaminated marine system, and the environmental effects of aquaculture operations on benthic communities.
Weston, D.P. and E.L. Amweg. 2007. Whole sediment toxicity identification evaluation tools for pyrethroid insecticides: II. Esterase addition.Environmental Toxicology and Chemistry 26:2397-2404.
Weston, D.P., E.L. Amweg, A. Mekebri, R.S. Ogle and M.J. Lydy. 2006. Aquatic effects of aerial spraying for mosquito control over an urban area.Environmental Science and Technology 40:5817-5822.
Weston, D.P., R.W. Holmes, J. You, and M.J. Lydy. 2005. Aquatic toxicity due to residential use of pyrethroid insecticides. Environmental Science and Technology 39:9778-9784.
Weston, D.P., J.C. You, and M.J. Lydy. 2004. Distribution and toxicity of sediment-associated pesticides in agriculture-dominated water bodies of California's Central Valley. Environmental Science and Technology 38(10):2752-2759.
Weston, D.P., W.M. Jarman, G. Cabana, C.E. Bacon, and L.A. Jacobson. 2002. An evaluation of the success of dredging as remediation at a DDT-contaminated site in San Francisco Bay, California, USA. Environmental Toxicology and Chemistry 21:2216-2224.
Weston, D.P. and K.A. Maruya. 2002. Predicting bioavailability and bioaccumulation using in vitro digestive fluid extraction. Environmental Toxicology and Chemistry 21:962-971.
Mayer, L.M., Weston, D.P., and Bock, M.J. 2001. Benzo(a)pyrene and zinc solubilization by digestive fluids of benthic invertebrates - a cross-phyletic study. Environ. Toxicol. and Chem. 20(9):1890-1900.