Table 4.

DBPs formed by chlorination of pharmaceutical/medical products and their toxicity. (Reference: (Wang et al. 2020a, b), (Negreira et al. 2016; 2015a,b,c), (Romanucci et al. 2019), (Duirk et al. 2011))

Compounds that formed DBPs with chlorine	Reaction media used in the study	DBP analogues detected	Status of toxicity assaya
Antibiotics i. Ciprofloxacin ii. Sulfamerazine iii. Chloramphenicol	Milli-Q water	THMs, HAAs (BCAA, TCAA, DCAA, MBAA, and MCAA), HKs, HANs, and TCNM	+
Anti-cancer drugs i. Etoposide	River water, WWTP influent, and effluent	By-product 1 and 2b (BP1: C28H29O13−, BP2: C26H25O13−)	−
ii. Tamoxifen (TAM)	Ultra-pure water and wastewater	OH-TAMc DBPs: DBP-438: C26H28O3NCl, DBP-472: C26H27O3NCl2, DBP-422A: C26H28O2NCl, DBP-422B: C26H28O2NCl, DBP-456: C26H27O2NCl2, DBP-440: C25H23O2NCl2, and DBP-454: C26H25O2NCl2 OH-D-TAMc DBP: DBP-424: C25H26O3NCl, DBP-458A: C25H25O3NCl2, DBP-458B: C25H25O3NCl2, DBP-458C: C25H25O3NCl2, DBP-408: C25H26O2NCl, DBP-442; C25H25O2NCl2, and DBP-440; C25H23O2NCl2	+
iii. Erlotinibd	Ultra-pure water and wastewater	TP-444: C22H22O5N3Cl, TP-428A: C22H22O4N3Cl, TP-428B: C22H22O4N3Cl, TP-428C: C22H22O4N3Cl, TP-462A: C22H21O4N3Cl2, and TP-462B: C22H21O4N3Cl2	−
iv. Vinca alkaloids: vincristine, vinblastine, vinorelbine, and deacetyl vinorelbyne	Ultra-pure water and wastewater	Total of sixty-five by-products were formed including twenty mono, 8 di-, and 2 tri-chlorinated compounds.	−
Tramadol (TRA)	Milli-Q water	BP1: C16H24ClNO2, BP2: C14H21NO3, BP3: C14H18O3, BP4: C16H23NO2, BP5: C17H23ClO5, BP6: C16H23NO3, and BP7: C15H20N2O3	+
Iodinated contrast media (ICM); iopamidol, iohexol, and iopromide	Purified water and river watere	Iodo-THMS: dichloroiodomethane, dibromoiodomethane, chlorodiiodomethane, bromochloroiodomethane, bromodiiodomethane, and iodoform. Iodo-acids: iodoacetic acid, bromoiodoacetic acid, (Z)-3-bromo-3-iodopropenoic acid, (E)-3-bromo-3-iodopropenoic acid, and (E)-2-iodo-3-methylbutenedioic acid.	Iodo-THMs + iodo-acids +

^a+ indicates toxicity assessment has been done in the respective study and the by-products were found to be toxic, − indicates toxicity assessment has not been carried out in the respective study.

^bProposed chemical formula.

^cDBPs were formed from metabolites of TAM.

^dOut of total 19 products formed, only chlorinated ones are listed.

^eIohexol and iopromide generated I-DBPs only in purified water.