Environmental Toxicology

Members

Luc P. Belzunces, DR1          

Claude Collet, CR1                         

Jean-Luc Brunet, IE2                     

Marianne Cousin, AI                        

Mercédès Charreton, AI                 

Sylvie Tchamitchian, TRS             

Keywords

Toxicity, electrophysiology, metabolism, fertility, reproduction, nervous system, muscle contraction, pesticides, modes of action, pollutants, bees, man, invertebrates, biomarkers, bioindicators, environmental health.

Missions

The task of the Environmental Toxicology Laboratory (LTE) is to study the effects of plant protection products and, in general, pollutants of different origins in biological organisms, and bees in particular. The themes addressed mainly focus on the effects of low doses of toxins in bees and humans.
The research developed aims to understand the modes of action of toxicants which lead either to deleterious effects at sublethal doses and low doses or to differential effects, the effects of which vary according to the physiological and developmental state of the organism . Among the deleterious effects at sublethal doses, two axes of study are favored: (i) effects induced by interactions between chemical and biological stressors and (ii) physiological, neurological and behavioral effects at low sublethal doses.
In order to establish toxicological knowledge on an organism biology that is as well characterized as possible, LTE develops, in parallel, fundamental research, notably on the functioning of the nervous system and the physiological systems controlled by the nervous system, bee metabolism, Reproductive function in males and queens of bees and the immune system. Basic and toxicological research is therefore developed using a multidisciplinary approach that combines specialties such as biochemistry and molecular and cellular biology, physiology, neurobiology, pharmacology and ethology.

Main lines of research

1.Effects of pesticides at low doses.

Attention is drawn to the deleterious effects induced by low doses of toxic by considering both acute toxicity at doses <1 μg / kg body weight and chronic toxicity at exposure levels <1 μg / Kg of food or environment.
The work is developed using a multidisciplinary approach with an experimental scale that extends from the molecule to the population. This approach makes it possible to characterize all types of effect, whether molecular, cellular, metabolic, physiological or behavioral.

2. Interactions between Stressors

Interactions between pesticides

The main challenge is to implement a relevant assessment of the risks presented by pesticide associations in honey bees, particularly considering synergistic actions. Because of their unpredictable nature, the phenomena of potentialisation are the object of particular attention.

Interactions between Toxics and Pathogens

It is a question of investigating the effects of associations by focusing attention on the associations that can occur at low noise, that is, in the presence of pathogens that do not induce pathologies and pesticides, Leading to no noticeable effects on colonies.
Various aspects of toxico-pathological interactions are studied: (i) Modulating the pathogenicity of microorganisms by pesticides, (ii) Modulating the toxicity of pesticides by pathogens and (iii) Modulating the efficacy of veterinary drugs Pesticides.

3. Modes of action of stressors

Pesticides have primary targets responsible for the expected effect, as this notion of expected effect is obviously strongly linked to the target organism (herbicidal action in plants, insecticidal action in insects, etc.). However, at sub-lethal doses, biological targets differ from those that induce lethal effects. These targets are of greater affinity and lead to different mechanisms of action depending on the level of exposure. LTE studies the targets and metabolic pathways involved in the action of pesticides at low doses and in the interactions between pesticides and pathogens.