Sensitivity of ecotoxicological tests in analysis of superfund sites

During the analysis of environmental risk posed by hazardous waste disposal sites, ecological impact on whole ecosystems should be assessed. It requires a complex testing scheme where surrogate species represent key elements of the ecosystem. However, different organisms are exposed to a differing degree, also, their sensitivity to the same contaminant may vary. A possible way to determine which test reflects most the actual toxic conditions, correlation can be calculated between the measured ecological parameter (such as growth inhibition, mortality, etc.) and a contaminant gradient. The basic aim of this study was to determine which ecotoxicological test shows the best correlation with the measured analytical parameters. The selected tests were Lemna minor (representing primary producers), Thamnocephalus platyurus (a primary consumer organism) and Vibrio fischeri (decomposer). When testing soil samples, the Thamnocephalus test showed excellent consistency with most contaminants but was oversensitive in the case of groundwater samples. The Vibrio fischeri bioluminescence inhibition test (ToxAlert) behaved in a different way, reflecting well the distribution of most contaminants in groundwater samples. Finally, Lemna test proved to be completely inadequate.