n-TiO2 and CdCl2 co-exposure to titanium dioxide nanoparticles and cadmium: Genomic, DNA and chromosomal damage evaluation in the marine fish European sea bass (Dicentrarchus labrax)

Due to the large production and growing use of titanium dioxide nanoparticles (n-TiO2), their releasein the marine environment and their potential interaction with existing toxic contaminants represent agrowing concern for biota. Different end-points of genotoxicity were investigated in the European sea bassDicentrarchus labrax exposed to n-TiO2(1 mg L−1) either alone and combined with CdCl2(0.1 mg L−1) for7 days. DNA primary damage (comet assay), apoptotic cells (diffusion assay), occurrence of micronucleiand nuclear abnormalities (cytome assay) were assessed in peripheral erythrocytes and genomic stability(random amplified polymorphism DNA-PCR, RAPD assay) in muscle tissue. Results showed that genometemplate stability was reduced after CdCl2and n-TiO2exposure. Exposure to n-TiO2alone was responsiblefor chromosomal alteration but ineffective in terms of DNA damage; while the opposite was observedin CdCl2exposed specimens. Co-exposure apparently prevents the chromosomal damage and leads to apartial recovery of the genome template stability.