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    Yves Lévi


Interview of Yves Lévi

Professor at the University of Paris Sud, president of the scientific support group for the national medication plan and member of the national pharmaceutical academy.

According to a recent study by Anses, one quarter of samples on water intended for human consumption contain traces of medication. Untreated water contains the same substances, occasionally at even higher concentrations. What is your opinion on these results?

This first, major national study provides us with a snapshot of the situation in France and confirms, first, that aquatic environments are contaminated by traces of a large number of medicinal residues and, secondly, that certain systems for the production of drinking water cannot totally eliminate all medicinal substances. We should not forget that medicines are only part of the complex pollutants affecting our water resources, which also contain many other micropollutants such as pesticides, flame retardants, plasticisers, solvents, etc. This situation is not specific to France, indeed similar results have been noted in Asia, elsewhere in Europe and in the United States. All countries are impacted because aquatic environments are the last stop for all of our pollutants.

What are the risks involved with medicinal residues?

Medicines comprise a vast quantity of substances producing varied effects, including vasodilators, antibiotics, mutagens, antidepressants, anticonvulsants, etc. Their effects are well known for humans at the doses foreseen in the market-authorisation procedures. But today, we need to know the effects on aquatic organisms following chronic exposure at very low concentrations of medicinal substances and other micropollutants. This is all the more necessary that we have already observed certain effects on animals in the most polluted zones. Thanks to considerable progress in analytical chemistry, we know how to detect the presence of many substances even at very low concentrations. On the other hand, the means to precisely measure the biological effects and the overall responses have not yet been developed and validated. It is only by measuring those effects that it will be possible to calculate the environmental and health risks caused by the mixtures of pollutants.

You chair the scientific support group for the medication plan that has formulated some recommendations. What are the priorities?

First of all, establish a national list of priority medicinal substances that will be addressed with all the scientific means available in the plan. The plan is based on risk analysis, in four parts, 1) identify hazards (detect substances and their active metabolites), 2) measure toxic and ecotoxic effects as a function of their concentrations, 3) analyse mixtures and 4) determine the exposure of populations and ecosystems by grouping our forces on a few study sites that are representative of the pressures requiring work. The resulting data will make it possible to determine the environmental and health risks, to develop new tools, to acquire new data and to prepare predictive models to assist managers. To make progress, it is essential to have data on the consumption of medicines in the studied river basins. We have suggested the creation of a joint database on the subject, open to all and free of cost.

You highlight the particular status of medicines among the many pollutants...

There is a certain ambiguity concerning medicines. They are produced and used to cure disease and improve our life expectancy, yet they have unfortunately also become pollutants. That is why the scientific support group recommends not only developing technologies and strategies to process the residues in wastewater and drinking-water production systems, but also to address the socio-economic aspects by studying the acceptability of risks as well as how medicines are prescribed and consumed. Given the prohibitive cost of eliminating medicinal residues in aquatic environments, it is important to raise the environmental issues with respect to medical consumption, while avoiding any negative impact on public health.


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