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DEPE | Séminaires BEEPSS / BEEPSS Seminars » From ecotoxicology to stress ecology

From ecotoxicology to stress ecology

Last update: : Tuesday 3 October 2017, by Nicolas Busser

Presented by: Renaud Scheifler, Chrono-environnement, Université de Franche-Comté / CNRS, Besançon
Date: Thursday 19th Oct 2017, 13:30-15:00
Place: IPHC, Amphithéâtre Grünewald, bâtiment 25

Ecotoxicology is the science studying the fate and the effects of pollutants in the environment. More than 133 millions of substances have been registered worldwide, the toxicity of most of them being few or even not documented. Consequently, there has been a strong social demand for concepts and methodologies allowing assessing the toxic effects of substances, either before their industrial use and release into the environment or after them. Both approaches allowed the development of different and complementary paradigms.

The laboratory-based paradigm was mainly based upon dose-response relationships obtained from standardized lab tests, performed on various organisms and whose results were used to underpin decisions on authorization of chemicals and on derivation of environmental quality criteria. A second framework is the study of toxic chemicals and ecological responses in the field, usually along pollution gradient from point sources emitting a single chemical or a simple mixture of chemicals. Ecological variables on target organisms are studied as a function of distance from the source, with the hypothesis that high concentrations close to the source are associated to adverse effects. Data may then be used to derive critical concentrations in relation to effects in the field.

Despite the undoubtful efficiency of those two approaches to give sound scientific data upon which environmental protection against pollutants could have been built, these paradigms suffer from strong limitations. Apart from the speed of substance production that often overtakes risk assessment regulatory procedures, the two approaches generally oversimplify the system studied and do not consider pollution as only one of the numerous stressors that may affect natural populations. A new paradigm has therefore emerged recently, that proposes to consider pollutants and pollution impacts (i.e. ecotoxicology) in the real complexity of ecosystems (stress ecology).

In the present talk, I will present shortly those paradigms and some results from our team regarding the second and the third paradigms, in particular the relationship between pollutants and pathogens in wildlife.