The effect of silver nanoparticles on the mutagenic and the genotoxic properties of the urban wastewater liquid sludges

Nanoparticles are very effective compounds to transform and detoxicate common environmental contaminants. For this reason, crude urban liquid wastewater sludges were treated by silver nanoparticles (Ag-NPs, 100 nm) for 24 h. Both Ag-NPs' treated and untreated sludges were examined for the evaluation if there are possible mutagenic/anti-mutagenic, cytotoxic, and genotoxic/anti-genotoxic effects by Ames and Allium cepa tests. The results were then subjected to statistical analyses by using SPSS software and p < 0.05 was accepted as a significant value. The data obtained from the Ames test showed that while untreated crude liquid sludge had a significant mutagenic effect, Ag-NP-treated one decreased its mutagenicity. Similar effects were also observed in the chromosome aberration-Allium cepa tests. Significant chromosome aberrations observed were C-metaphase, sticky metaphase, sticky anaphase, anaphase bridge, vagrant chromosome, and multipolar anaphases. Both tests demonstrated that silver nanoparticle treatment decreased the major mutagenicity and genotoxicity detected in the liquid wastewater sludges.