Simple two‐step sediment extraction procedure for use in genotoxicity and toxicity bioassays

Three simple sediment extraction procedures, using Milli-Q water, DMSO, and methanol, were applied to 16 sediment samples collected from the Thames River, Ontario, Canada. The three extracts were tested for the presence of toxicity and genotoxicity using the Microtox,® Toxi-Chromotest,® and Mutatox® (with and without S9) procedures. Results of the study indicated that the Mutatox genotoxicity screening test was an extremely sensitive procedure responding to chemicals in all three types of extracts. Methanol was found to be more efficient than DMSO in extracting toxic and genotoxic chemicals from these sediments. Procedural details and results are discussed.