Ethidium bromide (EtBr), is considered as the one of the first hazards to the environment when discharged into the water drainages with higher permissible levels, it act as a mutagenic interaction with molecular structure of genomic DNA and RNA. Recent studies have focused on surface modification of hydrophobic polymer matrices is an alternative way to change their surface properties. In the present work used the active polymer type of polyvinylidene chloride (PVDC), modified with extracted chitosan and titanium dioxide-(NWs or NPs)-loaded with gold nanoparticles (AuNPs) as a promising thin film-membranes (TFMs)-nanocomposites as PVDC-Cs/TiO2-(NWs or NPs)-AuNPs, furthermore, a halogen lamp 50 W/m2 was used with fixed distance 20 cm away from the TFMs nanocomposite to lose mutagenic property of ethidium bromide (EtBr). The synthetic membrane-(TFMs), were characterized by UV-Visible spectra, Fourier transform infrared (FT-IR), X-ray diffraction (XRD) pattern, and transmission electron microscope (TEM). The obtained data exhibited that ~ (80–95) % was degraded with high efficiency within 1 h and with high rates ~ (0.427– 2.75) x10-4 mol dm-3sec-1 and efficient quantities (Qe) by mg/g EtBr, within aeration process. The final products of EtBr were detected by HPLC-Chromatography; ~ 75% of EtBr was mineralized within 1 h. thus TFMs-nanocomposites were used efficiently to lose the mutagenesis.