Pharmaceutical residues and ecotoxicology in seawater – Pharm@ecotox

The pharmaceutical substances represent a diverse collection of over 1000 biologically active molecules used in human and veterinary medicine. Increased consumption of drugs and the development of more powerful analytical techniques in environmental resulted in the identification of these emerging contaminants in all aquatic compartments, ranging from the effluent of wastewater treatment plants, surface water, groundwater in the marine environment . Unlike conventional pollutants (pesticides, detergents, hydrocarbons ....), pharmaceutical residues are released continuously and at low doses in the environment, leading to potential chronic poisoning.
From a regulatory standpoint, the dangers posed by the release of pharmaceutical substances towards aquatic organisms are taken into account in recent years and only when the predicted concentrations in the environment exceed a threshold value of 0.01 ?g/l. Thus the data on the ecotoxicity of these substances are relatively sparse. The studies conducted so far on the topic mainly concern the identification and determination of residues in surface waters with a strong interest in terms of human health towards the consumption of drinking water. The available ecotoxicological data mainly concern hazard assessment related to acute toxicity. They focused on fifteen of molecules while their metabolites and certain drug classes such as anti-cancer agents and neuroleptics are poorly informed. Finally, data on the impact of these residues in sea level and especially on invertebrates is extremely low.
Our project aims to assess the impact of these substances from a global ecotoxicology point of view towards the aquatic organisms but also in marine organisms and especially in those with a significant economic impact for Normandy: abalone, oysters, cuttlefish. An integrated approach will link the observed effects on marine organisms to measure environmental contamination carried out into 3 separate zones: a densely anthropized area, a moderately anthropized area and a breeding area. Beside theses measures, the level of contamination for individuals will be done.
To determine the potentially toxic residues in silico, in vitro and in vivo methods will be used. The use of in silico approaches coupled with experimental validation will predict the toxicity of many residues and their metabolites belonging to different drug classes. This approach can be used within a regulatory framework. It will also highlight some particular modes of action contributing to a better understanding of mechanisms in relation to toxic action in invertebrates. Pharmaceutical substances are inherently biologically active substances. In silico approach will be combined with an in vitro approach to highlight potential effects on specific physiological functions of invertebrates: immune system, digestive system, nervous system, endocrine system and DNA. However, if in vitro assays allow sensitive detection and early effects of exposure to a contaminant, in vivo assays are essential for the study of long-term effects. Therefore, according to the analytical results, impacts on the same physiological functions with environmental concentrations will be assessed.