## 3 Endocrine-Disrupting Compounds EDCs
### Non-steroidal Anti-Inflammatory Drug Degradation  
Non-steroidal anti-inflammatory drugs (NSAIDs), including analgesics, are among one of the most common groups of pharmaceutical contaminants, especially diclofenac (DCF) and ibuprofen (IBU). Consumption of these drugs is increasing every year [91]; the levels of DCF concentrations identified in surface waters have reached 15 \(\upmu\)g dm\({}^{-3}\) while in the waters discharged by wastewater treatment plants it can reach 5.5 \(\upmu\)g dm\({}^{-3}\)[92]. Both DCF and its metabolites, 5-hydroxy diclofenac and N, 5-dihydroxydxidlofenac, can cause liver damage in humans [93]. Significant population declines in Asian Gyps vultures have also been associated with the contamination of their natural habitat with diclofenac [94]. The relatively low removal of DCF from wastewater in conventional treatment plants (20-35%) has been repeatedly indicated, thus suggesting that this drug is resistant to biodegradation [95,96]. One of the first tests for DCF removal concerned the use of gamma radiation to decompose 0.1 M DCF in an aqueous solution [97]. It has been shown that both the hydroxyl radical \({}^{\bullet}\)OH and the hydrated electron e\({}_{\text{aq}}\)\({}^{-}\) participate in the reaction of DCF decomposition and reduction in toxicity. It has been shown that in the \(\gamma\)/N\({}_{2}\)O system, the dose needed to decompose 480 \(\upmu\)M was reduced from 7.4 to 1.47 kGy as compared to free O\({}_{2}\)[98]. It was also noted that the addition of H\({}_{2}\)O\({}_{2}\), S\({}_{2}\)O\({}_{8}\)\({}^{2-}\), or the saturation of the solution before irradiation with N\({}_{2}\)O significantly increases the degree of mineralization. The radiolytic degradation of diclofenac mainly occurs via hydroxyl radical reactions, and the quantitative participation of reactive radicals can be represented as follows: \({}^{\bullet}\)OH \(>\) e\({}_{\text{aq}}\)\({}^{-}\)\(>\)\({}^{\bullet}\)H [99]. The determined rate constants for the reaction with the hydroxyl radical \({}^{\bullet}\)OH and electron e\({}_{\text{aq}}\)\({}^{-}\) are (1.24 \(\pm\) 0.02) \(\times\) 10\({}^{10}\) M\({}^{-1}\) s\({}^{-1}\) and (3.1 \(\pm\) 0.2) \(\times\) 10\({}^{9}\) M\({}^{-1}\)s\({}^{-1}\), respectively [83], which is in agreement with data presented previously for \({}^{\bullet}\)OH 9.0 \(\times\) 10\({}^{9}\) M\({}^{-1}\)s\({}^{-1}\)[100] and for \({}^{\bullet}\)OH (9.29 \(\pm\) 0.11) \(\times\) 10\({}^{9}\) M\({}^{-1}\)s\({}^{-1}\) and (1.53 \(\pm\) 0.03) \(\times\) 10\({}^{9}\) M\({}^{-1}\)s\({}^{-1}\)[101]. The presence of various natural waters, i.e., nitrate, nitrite, carbonate, or bicarbonate, have reduced the efficiency of DCF degradation process. It has been shown that the DCF degradation efficiency is definitely higher in acidic aqueous solutions than in alkaline or neutral ones [102]. The presence of humic acid had a negative effect on the degradation of diclofenac. At 0.8 kGy, when the humic acid concentration was 30 mg dm\({}^{-3}\), the degradation efficiency of diclofenac decreased from 80.8% to 62.9% [16]. Regarding DCF decomposition in natural aqueous matrices, the DCF content of these samples was at levels previously determined for this type of natural samples [83]. To achieve 100% degradation efficiency of DCF 10 \(\upmu\)g dm\({}^{-3}\) in river water the required dose was 100 Gy, while in hospital wastewater it was 250 Gy. An electron beam was also used to degrade DCF in aqueous solutions, similar to gamma radiation a 100% degradation efficiency was obtained at relatively low doses while mineralization occurred much slower even for higher doses [103].