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Updated: Jul 25, 2026

Sediment Core Sectioning and Extraction of Pore Waters under Anoxic Conditions
Published on: March 7, 2016
Sediment core versus grab samples: evaluation of contamination and toxicity at a DDT-contaminated site
C W West1, G L Phipps, R A Hoke
1U.S. Environmental Protection Agency, Environmental Research Laboratory, Duluth, Minnesota 55804.
Abstract:
Four sites from a stream system near Huntsville, Alabama, contaminated with DDT and its metabolites, were sampled using a coring device. Grab samples were also collected at these and five other sites. Analytical and toxicological evaluations were made on both sets of samples. Core samples provided vertical delineation of toxicity and contamination in sediments, and documented periods of sedimentation with clean material, which appears to be isolating the contaminated sediments from benthic communities. Grab samples yielded less information about the sites. Relationships between DDT concentration and sediment toxicity to Chironomus tentans were similar regardless of the sampling method. Substantial increases in toxicity occurred in most samples when concentrations exceeded 3000 micrograms of DDT residue/g organic carbon.
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