## 3 Endocrine-Disrupting Compounds EDCs
### Estrogen Degradation  
Natural estrogens are estrone (E1), 17\(\beta\)-estradiol (E2), and estriol (E3). If they enter living organisms from the outside, they are regarded as endocrine-disrupting compounds. E2 is the most common and causes the most endocrine disruption, although several E2 metabolites also have estrogenic endocrine activity. Chemically, E2 is a steroid that is a derivative of estrone. Estrogens play an important role in human health; however, when released into the environment, they become a problem. Synthetic estrogens are used as an ingredient in some oral contraceptives and in hormone replacement therapy [39]. In recent years, with the development of sensitive analytical techniques, it has become possible to determine estrogens at low concentration levels. It has been shown that conventional wastewater treatment plants are not able to completely degrade this type of pollutant, and their removal requires the search for more advanced technologies. Recently, natural estrogens have been reported in both drinking water and surface water [39]. So far, all knowledge about the adverse effects of estrogens on living organisms has meant that estrogens and their degradation products have been the first, next to diclofenac, to be included in the watch list in accordance with Directive 2013/39/EU of the European Parliament and of the Council adopted on 12 August 2013. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Compound** & **Initial** & **Dose/Kind** & **Yield of Degradation/Mineralization** & **Refs.** \\ \hline Sulfamethoxazole (SMX) & 0.1 mM & 5 kGy/\(\gamma\) & Decomposition—100\% & [29] \\ \hline SMX & 0.1 mM & 4 kGy/\(\gamma\) & Improvement in biodegradability & [30] \\ \hline Lincomycin (LMC) & 17 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Improvement in biodegradability of about 18.9\% & [22] \\ \hline SMX & 17 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Improvement in biodegradability of about 28.33\% & [22] \\ \hline Tetracycline (TCN) & 17 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Improvement in biodegradability of about 36.62\% & [22] \\ \hline SMX & 1 mg dm\({}^{-3}\) & 300 Gy/\(\gamma\) & Degradation—100\% & \\  & 2 mg dm\({}^{-3}\) & 300 Gy/\(\gamma\) & Degradation—96.2\% & [31] \\  & 5 mg dm\({}^{-3}\) & 300 Gy/\(\gamma\) & Degradation—91.3\% & \\ \hline SMX & 5 mg dm\({}^{-3}\) & 100 Gy/\(\gamma\) & Degradation—44.84\% & [31] \\  & +2 mM NO\({}_{2}\)– & 100 Gy/\(\gamma\) & Degradation—34.84\% & [31] \\ \hline SMX & 5 mg dm\({}^{-3}\) & 100 Gy/\(\gamma\) & Degradation—34.84\% & [31] \\  & +2 mM NO\({}_{2}\)– & & & \\ \hline Sulfadiazoline (SD) & 25 mg dm\({}^{-3}\) & & Degradation—100\% & \\  & +18.5 mM H\({}_{2}\)O\({}_{2}\) & 1 kGy/\(\gamma\) & Degradation—74\% & [32] \\  & +0.3 mmol dm\({}^{-3}\) Fe\({}^{2+}\) pH 2.6 & & & \\ \hline Sulfametiazol (SMT) & 20 mg dm\({}^{-3}\) pH 6.5 & 5 kGy/\(\gamma\) & Degradation—95.5\% & [33] \\  & & & Mineralization—6.8\% & [33] \\ \hline Amoxicillin, & 30 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Degradation—100\% & \\ Cerfradine, LMC, TCN & 30 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Degradation—100\% & \\  & 30 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Degradation—100\% & [34] \\  & 30 mg dm\({}^{-3}\) & 2 kGy/\(\gamma\) & Degradation—100\% & \\ \hline Amoxicillin, & 50 mg dm\({}^{-3}\), pH 9 & 30 kGy EB & Degradation—97\% & [35] \\ Ofloxacin, Cerfradine & 50 mg dm\({}^{-3}\), pH 9 & 30 kGy EB & Degradation—96.9\% & [36] \\  & 50 mg dm\({}^{-3}\), pH 9 & 30 kGy EE & Degradation—96.9\% & \\ \hline TCN & 300 mg kg\({}^{-1}\) & 1 kGy EB & Degradation—42.77\% & \\  & (Livestock samples) & 3 kGy EB & Degradation—62.20\% & \\  & & 5 kGy EB & Degradation—77.83\% & \\  & & 10 kGy EB & Degradation—90.50\% & \\ \hline Norfloxacin, Ciprofloxacinacin & 0.1 mM & 2 kGy/\(\gamma\) & Degradation—100\%/TOC reduction—25\% & [37] \\ \hline Ornidazole & 50 mg dm\({}^{-3}\) & 3 kGy/\(\gamma\) & Degradation—100\% & [38] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Selected antibiotic degradation using radiation technologies.