## 5 Conclusions  
This study indicated that there is a potential CBZ modulating effect, which led to an enhanced intake of As, where the total As and As species accumulation in the organs of the As + CBZ exposure group tended to increase compared to the As exposure group. However, the capacity to methylate the more toxic inorganic As species to its less toxic methylated forms was comparable in the As and As +CBZ groups, suggesting As toxicity could potentially be more pronounced in the As + CBZ group than the As group. This study also found that high As exposure interacted with CBZ in the As + CBZ group but did not cause an enhanced uptake of CBZ in the liver compared to the CBZ alone exposure group. It was observed that exposure to CBZ at concentrations detected normally in surface water caused its accumulation in the liver of the CBZ exposed groups (CBZ and As + CBZ), raising concerns about potential toxic effects in mammals from long-term exposure. However, the concentration levels detected were too low to assess the metabolic pathway of the drug at subtherapeutic exposure concentrations in the investigated mammalian organisms. Glutathione peroxidase (GPx) activity, used to assess the antioxidant enzyme defence responses against single and co-exposure of the two pollutants, showed the CBZ group exhibited comparable activity to that of the control group, while the As group showed down-regulation and the As + CBZ group showed up-regulation. These results suggest that the CBZ group experienced minimal oxidative stress conditions similar to the control group. The As group showed a rapid adaptation/response to curtail or offset potential oxidative stress tissue damage conditions compared to the slow adaptation/response in the As + CBZ group. These aspects are novel and deserve further elucidation. Moreover, the animals were exposed to a whole cocktail of pollutants, and their potential impact should be investigated as a whole in further research. Therefore, the potential mutual effects of emerging pollutants and risk elements should be targeted in future research because the co-exposure of wildlife to both groups of environmental pollutants cannot be avoided.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15031662/s1](https://www.mdpi.com/article/10.3390/app15031662/s1)]([https://www.mdpi.com/article/10.3390/app15031662/s1](https://www.mdpi.com/article/10.3390/app15031662/s1)). Figure S1: The results of statistical evaluation of the data; Table S1: The total arsenic contents in the individual organs (mg/kg) and initial and final body weights of the animals (g); Table S2: Total As and As species contents (mg/kg) in the liver samples; Table S3: GPx activity in blood plasma of the animals (U/mL).  
Conceptualization, J.S. and Z.C.; methodology and analyses, F.B., J.S., C.S., M.G., L.P. and F.M.; data processing, F.B. and J.S.; writing--original draft preparation, F.B.; writing--review and editing, J.S., Z.C. and P.T. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the grant project of GACR 23-07811S.  
The experimental procedure was approved by a committee from the Ministry of Education, Youth and Sports, Czech Republic; with approval code MSMT-1082/2017-2. The provision of animal care was supervised and authorized by [PERSON], (Ph.D.), holder of Certificate No. CZ 02201 issued by Central Commission for Animal Welfare of the Czech Republic.  
Not applicable.  
Data Availability Statement: The data presented in this study are available on request from the corresponding author.  
The authors declare no conflicts of interest.