Approach to the Analysis of Toxicant Interactions in the Aquatic Environment

Most methods currently used to evaluate the joint action (the effects of toxicants applied in combination) of two toxicants rely on toxicity estimates of the individual components and one mixture. For both theoretical andpractical reasons, such approaches are unsatisfactory oversimplifications that are insensitive when applied to experimental data. Although isoboles can be used to illustrate interactive patterns for several mixtures, direct statistical analyses of isoboles are awkward because the variances are not restricted to a single axis. An alternative approach is proposed based on a comparison of the assumption of simple similar action with two models of interactive joint action.