Étude de xénobiotiques dans les eaux de surface au luxembourg

Xenobiotic concentrations in river waters of Luxembourg

Centre de Recherche Public Gabriel Lippmann, 41, rue du Brill, L-4422 Belvaux, Luxembourg

Auteur de correspondance : pailler@lippmann.lu

Reçu : 10 Février 2008
Accepté : 15 Avril 2008

Résumé

Le principal objectif de ce travail était d’évaluer la concentration et la dynamique de certains xénobiotiques (hormones, antibiotiques, analgésiques) dans les eaux de surface au Luxembourg. A cet effet, plusieurs points d’échantillonnage ont été réalisés dans une station d’épuration, le long de l’Alzette (profil longitudinal) et de façon plus ponctuelle sur un petit bassin d’affluent lors d’épisodes de crue. Un deuxième objectif était d’extraire tous ces composés en une seule étape sur phase solide (SPE) pour les quantifier en spectrométrie de masse en tandem. Les résultats obtenus montrent essentiellement une forte teneur en ibuprofène et des taux non négligeables en hormones et sulfonamides.

Abstract

The first studies which deal with the impact of xenobiotic compounds on human health and the environment were published in the early 1990’s. These studies pointed out the endocrine disrupting effect of some xenobiotics on biological functions in animals. This paper deals with the study of some xenobiotics and their occurrence in the surface waters of Luxembourg. Different sample points were chosen along the Alzette river, including a waste water treatment plant. Furthermore, flood events were investigated in a tributary of the Alzette, the Mess river. The twelve molecules analyzed belong to three families: the estrogens, the antibiotics (sulfonamides and tetracyclines) and the pain killers. With the goal to extract all these compounds with very different physico-chemical properties, a single step performing extraction method by solid phase extraction was developed on copolymer cartridges. After this concentration step, xenobiotics were quantified by High Performance Liquid Chromatography coupled with a tandem mass spectrometer with triple quadrupole. Among the twelve xenobiotics monitored, the pain killers are the most abundant in the surface waters. During flood events of the Mess river ibuprofen was measured at a concentration between 10 and 2300 ng/L; in the wastewater treatment plant, these concentrations reached 4000 ng/L. Compared to ibuprofen, sulfonamides reached concentrations of approximately 20 ng/L in the Alzette and 50 ng/L for the wastewater treatment plant. Because of their role in bacterial resistance these concentrations of antibiotics are of concern. Alarming are also the estrogen concentrations (1-240 ng/L) which may be responsible for disturbing the endocrine system in animals.