ABSTRACT
This chapter illustrates the application of rapid testing to studies of contaminant bioavailability and effect using single toxic metals and metal mixtures derived from contaminated sites. Soil samples were collected in the vicinity of an abandoned precious metal and base metal mining district in central Colorado. Free metal concentrations of elutriates were estimated from total metal concentrations and pH, and toxicity assessments were done using estimated free metal concentrations. Elutriates from contaminated soils strongly affected ciliate growth, and elutriates from those soils expected to be most toxic often completely inhibited ciliate growth. Methods for evaluating adverse effects of toxic substances rely on having test organisms of known size and age available for testing. Culturing test organisms often consumes much of the research effort leaving less time available for field evaluations of contamination. Features of test organism biology make microscale tests rapid and inexpensive, since the high cost of maintaining organism cultures is reduced.
