Comprehensive eco-geno-toxicity and environmental risk of common antiviral drugs in aquatic environments post-pandemic

The eco-geno-toxicological impacts of the most widely used antiviral drugs against SARS-CoV2 - ribavirin, ritonavir, nirmatrelvir and tenofovir - were investigated in freshwater organisms. Ribavirin and tenofovir exhibited the highest acute toxicity in the rotifer Brachionus calyciflorus at concentrations of a few mg/L while ritonavir and nirmatrelvir showed similar effects at tens of mg/L; acute toxicity of ribavirin was also observed in the crustacean Ceriodaphnia dubia at similar concentrations. In contrast, the crustacean Thamnocephalus platyurus showed the lowest sensitivity to the antiviral drugs tested with no sublethal effects. Chronic toxicity tests revelead that these antivirals induced effects in consumers at concentrations of environmental concern (ng-µg/L). Ribavirin showed the highest toxicity to the alga Raphidocelis subcapitata, while ritonavir showed the highest toxicity to B. calyciflorus and C. dubia. DNA damage and oxidative stress were observed in C. dubia at 0.001 µg/L and 0.1 µg/L when exposed to ritonavir and nirmatrelvir respectively, and at 1 µg/L when exposed to ribavirin and tenofovir. Toxic and genotoxic environmental risks were assessed with risk quotients for ritonavir, tenofovir and ribavirin exceeding the threshold of 1, indicating significant environmental concern.