Record Details
Field | Value |
---|---|
Title | Sediment characteristics as indicators of toxic cadmium and copper concentrations in Oregon estuaries |
Names |
Felstul, David R.
(creator) Hancock, Danil R. (advisor) |
Date Issued | 1987-04-29 (iso8601) |
Note | Graduation date: 1987 |
Abstract | Several physical and chemical characteristics of sediments have been proposed for use in tiered testing plans to predict the presence of trace metals in estuarine sediments. Correlations often exist, but the mere presence of a trace metal does not indicate toxicity; a more thorough approach is needed. Available information on natural background concentrations, bioavailability, and toxicity of Cd and Cu was used to determine concentrations likely to cause toxic effects in Oregon sediments. Concentrations of Cd and Cu in 31 sediment samples from nine Columbia River sites were measured using atomic absorption spectrophotometry. Correlations between the Cd and Cu concentrations and the sediment characteristics of grain size, oil and grease, volatile solids, total organic carbon, pH, iron, manganese were calculated. The percent of volatile solids was the factor which most often correlated significantly with Cd, whereas median grain size was the factor which most often correlated significantly with Cu. The characteristics best suited for predicting toxic concentrations of Cd and Cu--especially when data from other Oregon estuaries were considered--are, by weight, >5% volatile solids or >35% silt-size or finer grains. Below these indicator values, sediments with toxic concentrations of Cd or Cu are highly unlikely. |
Genre | Thesis/Dissertation |
Topic | Estuarine sediments -- Oregon |
Identifier | http://hdl.handle.net/1957/40599 |