Ecogenotoxicological assessment of the water quality of the Danube river (site Višnjica) based on DNA damage in various fish species

Abstract

This work represents the study of quality of the Danube River, in Belgrade, at the Višnjica site, by analyzing the genotoxicity of water by using fish as bioindicators. With a population of about 2 million inhabitants (Belgrade) and poor legislation regarding the discharge of wastewaters, monitoring is the first step in approaching this serious problem. To obtain information on the genotoxicity of water as a measure of DNA damage, the comet assay, which detects the effects of exposure, and micronucleus test, which detects permanent effect, were used. For the comet assay we have used three types of cells: blood, liver, and gills, while the micronucleus test was done on blood cells. The fish used as bioindicators are the common perch (Perca fluviatilis), vimba bream (Vimba vimba), common barbell (Barbus barbus), and white bream (Blicca bjoerkna). Regarding the comet assay, significant difference in DNA damage was observed between species in all tested tissues. Vimba bream and common barbell had the highest level of DNA damage in gills, white bream in liver and common perch in blood. In the case of the micronucleus test, the highest number of micronuclei was detected in white bream blood cells. The obtained results showed that there is no correlation between comet assay and the micronucleus test suggesting the importance of performing different bioassays on multiple types of fish tissues in order to find the best biomarker for assessing the genotoxic potential of water.