Features Etoposide Irinotecan Chemical structure Physical property [8] log Kow: 0.6, solubility: 59 mg/L --- Environmental occurrence [36] hospital effluent: 42 ng/L --- Ecotoxicology [17] EC50 > 10 mg/L in various assays --- Treatment strategy [21, 32] KMnO4, NaOCl electrolysis

Table 7: Summary of topoisomerase inhibitors.