Effects of Cadmium on Streams and Irrigated Agriculture in the Presence and Absence of Oil Shale Leachate

摘要

The goal of this study was to identify potential effects should oil shale leachates in Utah and Colorado reach hardwater stream ecosystems or irrigate agricultural lands. The experimental work focused on interactions between raw oil shale leachate and heavy metals in concentrations naturally occurring in these streams and how these interactions affect the toxicity and bioaccumulation of metals. For the studies on hardwater streams, eight identical stream microcosms were constructed and allowed to establish self-sustaining communities of aufwuchs and invertebrates on natural river substrates. Pairs of streams were exposed to treatments of 20 micrograms Cd/l (representing the most severe likely concentration in the natural streams), 20 micrograms Cd/l plus leachate from crushed raw oil shale, and crushed raw oil shale leachate alone. Sampling was conducted to determine changes in community structure and observe biological cadmium accumulation.