Genotoxicity assessment of disperse red 1 dye in aquatic species using fish cell lines

Abstract

After a dye is used in an industrial process, 1 to 5% is not used and stays in the water baths. This waste is usually treated in an activated sludge plant and the liquid effluent released in the aquatic environment. In general azo dyes are toxic to aquatic organisms and some types of dyes are more toxic than others. But although these compounds as well as their reduced/chlorinated transformation products can be found in aquatic ecosystems, mutagenicity data in aquatic organisms are scarce. In aquatic ecotoxicology assessment, alternative in vitro models such as fish cell lines represent standardized easy-to-use systems that can be conducted in fully controlled environment, giving fast, affordable and ethically eligible results. In this project, we propose to study two fish cell lines, representing an interesting eukaryotic model retaining specific fish physiological characteristics (ectothermia, tolerance towards osmolality variation and some specific metabolic and DNA repair capacities). Concerning genotoxicity, one of our goals in this work, is to use endpoints as sensitive as possible since Disperse Red 1 dye is found at rather low concentrations in rivers and could exhibit various modes of action leading to a large panel of lesions. Considering these criteria, we chose primary DNA damage (Fpg-modified comet assay), admitted as a very early and universal genotoxicity endpoint and micronucleus formation considered as an effect biomarker detecting unrepaired and post-mitotic lesions. Results obtained in this study will give us the possibility of evaluate the risk of Disperse Red 1 for the aquatic life and also provide scientific basis for the regulation of azo dyes in the aquatic environment. (AU)