Margueritta Al Zallouha, Yann Landkocz, Julien Brunet, Renaud Cousin, Eric Genty, Dominique Courcot, Stéphane Siffert, Pirouz Shirali, Sylvain Billet
Unité de Chimie Environnementale et Interactions sur le Vivant EA4492, Université du Littoral Côte d′Opale, 189 A Avenue Maurice Schumann, 59140 Dunkerque, France
The exposure of A549 cells to VOCs and by-products at the Air-Liquid Interface exposure system were tested and showed toxic effects. Additionally a catalyst setup coupled to the Vitrocell system for testing by-products of toluene oxidation has been validated. The toxicological analysis is done with a cell viability test (LDH) and a TaqMan gene expression kit (RT-qPCR).
Toluene is one of the most used Volatile Organic Compounds (VOCs) in the industry despite its major health impacts. Catalytic oxidation represents an efficient remediation technique in order to reduce its emission directly at the source, but it can release by-products. To complete the classical performance assessment using dedicated analytical chemistry methods, we propose to perform an untargeted toxicological validation on two efficient catalysts. Using biological system allows integrating synergy and antagonism in toxic effects of emitted VOCs and by-products, often described in case of multi-exposure condition. Catalysts Pd/α-Al2O3 and Pd/γ- Al2O3 developed for the oxidation of toluene were both coupled to a Vitrocell® Air-Liquid Interface (ALI) system, for exposure of human A549 lung cells during 1 h to toluene or to catalysts exhaust before quantification of xenobiotics metabolizing enzymes. This study validated initially the Vitrocell® as an innovative, direct and dynamic model of ALI exposure in the assessment of the performances of new catalysts, showing the presence of chemically undetected by-products. The comparison of the two catalysts showed then that fewer organic compounds metabolizing genes were induced by Pd/γ-Al2O3 in comparison to Pd/α-Al2O3, suggesting that Pd/γ-Al2O3 is more efficient for toluene total oxidation from a toxicological point of view.
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