Profile of toxic response to sediments using whole-animal and in vitro submitochondrial particle (SMP) assays

Abstract

A rapid bioassay for monitoring acute toxicity of wastewater, ground water, and soil and sediment extracts using submitochondrial particles (SMP) has been developed. The assay utilizes the mitochondrial electron transfer enzyme complex, present in all eukaryotic cells. Prior developmental work with pure chemicals chosen from the U.S. Environmental Protection Agency's (EPA) priority pollutant list documented order-of-magnitude predictability between the bioassay response and whole-organism tests (e.g., fathead minnow). Recent work has adapted the assay for analysis of uncharacterized environmental samples, including stormwater runoff, landfill leachate, and soil and sediment extracts. A feasibility study was performed to determine whether the SMP assay could detect toxicity in samples previously assessed for toxicity to amphipods. Acute toxicity tests using Hyalella azteca were performed on 30 sediment samples from Colorado's Arkansas River, Eagle River, and Chalk Creek watersheds, all of which have been directly or indirectly affected by heavy metal mine tailings and drainage. In parallel, two SMP assay protocols designed to differentiate between modes of toxicity were performed on elutriate samples from 23 of the above sites. The results from analysis of the sediments differed widely in the nature and degree of test responses. Significant correlation was found between the responses of the SMP electron transfer protocol and the whole-organism assay, and between the responses of the SMP electron transfer protocol and levels of zinc and sulfur, as determined by inductively coupled plasma spectroscopy.