AbstractThe toxic effect of dioxins and dioxin-like compounds have largely been studied using in vivo techniques; however, in vivo studies can be limited when rapid screening is required. Microtox® can be used as a rapid ecotoxicity assessment tool for dioxins in the environment, but studies on the assessment of dioxins and dioxin-like compounds using bioluminescent bacteria Allivibrio fischeri are limited. This study investigated the potential of using A. fischeri for assessing different dioxins and dioxin-like compounds, and the toxic effects of soils contaminated with dioxins and dioxin-like compounds were tested using different fractions of dioxins in soil to determine the appropriate way of assessing the toxic effects of contaminated soils. The results show that A. fischeri can potentially be used as a test species for rapidly evaluating toxic effects of dioxins and dioxin-like compounds in the environment. With the soil used in this study, the toxic effects of the water extracts (i.e., mobile fraction of dioxins) and the soil slurries (i.e., bioavailable fraction of dioxins) were similar to that of the controls. This suggests that the toxicity assessment of the organic extracts (i.e., total amount of dioxins) can be inappropriate in a managerial perspective, as the mobile or bioavailable fraction of contaminants in soils is often more of concern than the total amount of contaminants present in soils. Overall, when A. fischeri are to be used for a rapid toxicity assessment of dioxins-contaminated soils, different fractions of dioxins need to be assessed for better management of the contaminated soils.
Toxicity Assessment of Contaminated Soils of Solid Domestic Waste Landfill
