Environmental risk assessment of antineoplastic drugs: A case study in Florianópolis, Southern Brazil

Antineoplastic drugs are extensively used in cancer therapy and are mainly released into the environment via patient excretion. Due to their toxicological, mutagenic, and cytostatic effects, these compounds may pose risks to aquatic ecosystems and human health. This study assessed antineoplastic drug consumption in the Florianópolis region (southern Brazil) over a 1-year period using data from two high-complexity oncology centers. A total of 43 drugs were identified, with capecitabine, hydroxycarbamide, and fluorouracil showing the highest consumption rates (140.2, 113.0, and 11.6 µg.inhab -1 .day -1 , respectively). An environmental risk assessment was conducted in accordance with the European Medicines Agency (EMA) framework. Predicted Environmental Concentrations (PECs) were estimated for all compounds, and 20 drugs met the criteria for Phase II evaluation, although only 13 could be evaluated due to the availability of ecotoxicological data. Risk Quotient (RQ) analysis indicated that only imatinib initially presented RQ > 1; however, its RQ decreased to 1 in Phase II tier B. Overall, no significant environmental risk was identified, with RQ values ranging from 0.325 (imatinib) to 1.1 × 10 − 6 (ifosfamide), well below moderate-risk thresholds. Physicochemical properties indicated bioconcentration potential for mitotane, tamoxifen, and diethylstilbestrol, and high persistence for vinblastine. These results reinforce the need for long-term, compound-specific monitoring and future regulatory guidelines for antineoplastic drugs as emerging contaminants.