Toxicity of mixtures of organic chemicals to microorganisms

Microbial Toxicity in Soil Medium

“…Microtox Speece, 1990, 1991) and activated sludge and Polytox (Nirmalakhandan et al, 1994). Moreover, from the results of tests carried out at different moisture-holding capacities it can be concluded that the test procedure is valid and reproducible at different soil moisture levels.…”

Structure– and Property–Activity Relationship Models for Prediction of Microbial Toxicity of Organic Chemicals to Activated Sludge

“…Even though numerous toxicological studies on higher aquatic life forms have been reported in the literature, systematic toxicity assays of SOCs on microorganisms used in waste mineralization have been undertaken only recently (Blum and Speece, 1990;Tang et al, 1992;Nirmalakhandan et al, 1993;Sun et al, 1994). Apart from the IC values, these data sets also encode valuable toxicological information: interspecies correlations; organism sensitivity; chemical structure-toxicity and chemical property-toxicity relationships, etc.…”

“…Using these techniques, it is now possible to derive models from available test results that could predict reliable data for related, untested chemicals. While the state-of-the-art QSAR and QPAR techniques cannot yet completely replace experimental testing, they are being extensively used to complement test data in design of new chemicals with desired characteristics (Cramer, 1980); environmental assessments (Borman, 1990); screening and grouping of similar chemicals for collective evaluation ; prioritization of testing ; classification of mechanisms and modes of toxic action (Bradbury, 1994); and prediction of joint toxicity in mixtures of chemicals (Nirmalakhandan et al, 1993;Hall et al, 1996;Xu and Nirmalakhandan, 1997).…”

Comparative evaluation of the effects of pesticides in acute toxicity luminescence bioassays

“…Mixtures of compounds may pose bigger problems because the toxicity of a mixture is not easily linked to individual toxicities of components in the mixture; synergistic and antagonistic response are know to occur [2][3][4]. Thus, for predicting the impact of a wastewater stream on the ecology of a receiving body such as a biological wastewater treatment facility, or a lake, the toxicity of the contaminated water needs to be determined with single and multiple contaminants and with a selection of assay methods.…”