Showing papers by "Robert A. Hoke published in 2020"

Freshwater Sediment Quality Criteria: Toxicity Bioassessment

Abstract: Chironomus tentans is a representative of a group of insects known as the midges, which are widely distributed in freshwater sediments during their larval stage of development. Ambient water quality criteria have been established in the United States for a relatively small number of contaminants, but no such criteria have yet been developed for sediments. Sediment toxicity can be estimated by comparing the concentrations of toxic substances associated with sediments with known dose-response relationships. The theory on which the equilibrium partitioning approach is based assumes contaminants associated with the solid phase of sediments will reach an equilibrium with the porewater and associated organisms which can be predicted from the physical and chemical properties of the sediment and chemical of interest. The results of bioassays with benthic organisms can then be compared to the concentrations of individual toxicants in the sediment to determine where on the dose-response relationship the sediment is for each chemical.