Keywords: EC50, eco-toxicity tests, hormesis, Matlab, nonlinear regression, polynomial functions, acute toxicity, environmental samples, environment, health, dose–response relationship
A new approach based on polynomial functions for measuring the acute toxicity of environmental samples
In this paper, a new mathematical approach for the estimation of acute toxicity in environmental samples is proposed. The concentration of pollutant or the amount of sample producing the inhibition of 50% of the living organisms used for the test (EC50) is determined by means of Polynomial Functions (PF) applied to the experimental x (concentration of pollutant) and y (concentration or number of living organisms) points instead of using the common approach by Exponential Regression Analysis (ERA). The peculiar characteristic of the proposed method is its ability to describe the dose–response relationship of a pollutant including both growing (i.e. hormetic) and lethal effects, without requiring the exclusion of hormetic points that do not obey to the exponential relationship of a lethal response. For this reason, PF approach is proposed as an alternative method to the common estimation of EC50 by ERA method. The use of PF approach is described reporting advantages and disadvantages with respect to the conventional ERA method.