Toxicity of mixtures of aquatic contaminants using the luminescent bacteria bioassay

Abstract

The toxic effect of single organic contaminants to aquatic biota is relatively easy to assess using classic aquatic toxicity bioassays. Unfortunately, contaminants are present in the aquatic environment in mixtures of unknown composition. Moreover, antagonistic and synergistic interactions make the prediction of the real environmental hazard posed by organic contaminants more complicated. A mathematical algorithm has been developed to predict the toxicity of mixtures of organic contaminants to aquatic biota using toxicity data for the individual components of the mixture. The MicrotoxQ toxicity bioassay was used to obtain the toxicity data for a set of chlorinated phenols that were used as test compounds to validate the model. The unique characteristics of the Microtox bioassay make it a perfect tool to confirm experimentally the ability of the model to estimate the combined toxic effect of mixtures of organic contaminants.

Toxicity of pesticides in wastewater: a comparative assessment of rapid bioassays

“…Interestingly, more complex mixtures, those with three and four components (Tables 6 and 7), were generally at least as toxic as the most toxic pure compound present, even though the latter constituted as little as 1/3 or 1/4 of the mixture. Toxicities of the mixtures did not have a consistent pattern with respect to the amount of most toxic component; in particular, mixture toxicity did not correlate with the weighted sum of toxicities of individual components present, as has been claimed for mixtures of certain toxicants [11]. Ribo and Rogers [11] showed that for many nonspecific toxicants, the mixture toxicity correlated with that of individual component toxicity in accordance with the equation: where EC 50 M is the toxicity of the mixture, C is concentration (mmol l −1 ), and subscripts A, B, etc., denote individual components.…”

Application of geochemical and ecotoxicity indices for assessment of heavy metals content in soils / Zastosowanie wskaźników geochemicznych i ekotokysycznych w ocenie zawartości metali ciężkich w glebach

“…A characteristic feature of Vibrio bacteria is the designation of a major part of their metabolic energy to luminescence. Any change in metabolism under the infl uence of a toxic substance causes a change in the produced luminosity (Ribo and Rogers 1990). Using bacteria for environmental monitoring gives very good results due to the short reaction time of a bacterial colony to the toxic effect of the harmful factor.…”

Study of Cr(VI) and Cd(II) Ions Toxicity Using the Microtox Bacterial Bioassay

“…Within the studied 6.0-9.0 pH range, the average EC 50 for phenol after 5 min exposure was 29.94 ±2.4 mg l -1 indicating the absence of significant change in toxicity due to pH. Our value is in accordance with the EC 50 values reported in literature (Hindwood and McCormick 1987;Ribó and Rogers 1990). When evaluating the effect of ionic strength, phenol EC 50 values were determined in different media.…”