Assessing exposure risks for aquatic organisms posed by Tamiflu use under seasonal influenza and pandemic conditions

- Environmentally relevant concentrations of anti-influenza drug have ecotoxicologically important effects.
- Tamiflu is unlikely to pose a significant chronic environmental risk during seasonal influenza.
- Chronic environmental risk posed by Tamiflu during pandemic is alarming.
- Tertiary process in sewage treatment plants is crucial in mitigating Tamiflu exposure risk.

Environmental pollution by anti-influenza drugs is increasingly recognized as a threat to aquatic environments. However, little is known about empirical data on risk effects posed by environmentally relevant concentrations of anti-influenza drug based on recently published ecotoxicological researches in Taiwan. Here we linked ecotoxicology models with an epidemiological scheme to assess exposure risks of aquatic organisms and environmental hazards posed by antiviral oseltamivir (Tamiflu) use in Taiwan. Built on published bioassays, we used probabilistic risk assessment model to estimate potential threats of environmentally relevant hazards on algae, daphnid, and zerbrafish. We found that Tamiflu use was unlikely to pose a significant chronic environmental risk to daphnia and zebrafish during seasonal influenza. However, the chronic environmental risk posed by Tamiflu use during pandemic was alarming. We conclude that no significant risk to algal growth was found during seasonal influenza and high pandemic Tamiflu use.