## 2 Contaminants of Emerging Concern (CECs)
### Pesticides (Other Than Organochlorine)  
Pesticide is a broader term that covers herbicides, insecticides, nematicide, fungicides, plant growth regulator, defoliants, desicants, and biocides. The pesticide pollution of surface waters or groundwater may have different pathways: surface run-off from farmyards, wastewater treatment plants, forestry, municipal use, grasslands and domestic gardens, or animal husbandry. Unlike pharmaceuticals, pesticides are designed to act against organisms (plants, insects) and have an inherent effect on the environment [28; 44]. In the European Union, the presence of pesticides in water is regulated through the Directive 2006/118/EC [72], which refers to groundwater, the Directive 98/83/EC [73] on the quality of water intended for human consumption, and the general Framework of Water Directive 2000/60/EC [74]. EU standard acceptable concentration for pesticides in ground water and drinking water is 0.1 \(\upmu\)g/L [73]. Concerning the surface waters, Directive 2013/39/EU includes on a priority substances list several pesticides, among which are: triazine, organophosphorus pesticides, phenylurea pesticides (diuron, isoproturon), the pyrethroid cypermethrin, and various organochlorine pesticides, which are considered persistent organic pollutants (POPs) [35]. Recent Decision 2015/495/EU [75], Decision 2015/495/EU, 2018/840/EU [36], and Decision 2020/1161/EU [37] updated the previous regulations and several compounds such as azoles fungicides (e.g., imazalil, metconazole, miconazole, penconazole, prochloraz, tebuconazole), neonicotinoids (imidazol, thiacloprid, thiamethoxam, clothianidin, acetaminophen), triallate, and methiccarb were included on the \"watch lists\" with predicted no-effect concentration (PNEC) values set as maximum acceptable method detection limit and EQS. Within the present research, seven studies on pesticides in the surface water samples, and sediment in the selected area were identified (Table 3). Target compounds selection was based on literature reporting the occurrence of the contaminants and the list of priority substances under the WFD [35]. Complex monitoring studies consider also the abiotic transformation products of such compounds, which in some cases may be more toxic, persistent, and bioaccumulative than the parent compounds (e.g., metolachlor-ESA, 2-hydroxypropazine, 2-hydroxysimazine, desethylturbylazine) [26; 45; 53]. Among the detected compounds in the Lower Danube basin, relevant concentrations were reported for carbendazim (in a range of 0.6-269 ng/L), atrazine (4-392 ng/L), metolachlor (80-150 ng/L), dimethoate (7-23 ng/L), and imazalil (2.5-80 ng/L) (Figure 4). Griseofulvin was detected in the Danube Delta and Siret River [10]. Maximum concentrations were reported generally in tributary Tisa, Morava, and Siret River [10; 39]. Higher concentration of dimethoate of 1222 ng/g was reported in Tisa River [39]. It is noteworthy that in the Dniester River, significantly higher concentrations than the Danube basin were reported, revealing the influence of untreated waters [26]. Thus, the concentrations of 4612 ng/L for metolachlor and 107 ng/L for imidalcoprin recorded in the Prut River are over 30 times higher than the maximum concentrations in the Danube basin. Terbuthylazine maximum concentration of 2514 ng/L in the Dniester River is also significantly higher relative to those reported in the Danube (of 200 ng/L) and in the Prut river (of 41.4 ng/L). Concentration of carbandazim (of 755 ng/L) was almost three times higher than that reported for the Danube. A maximum concentration of diuron of 1197 ng/L was measured in the central part of Dniester basin (Moldova) [26]. For comparison reasons, worth mentioning are the maximum concentrations of imazalil of 409.73 ng/L and diuron of 150 ng/L measured in the Ebro River basin (Spain) [76].