**6. Conclusions**

The authors have achieved the objectives proposed in the research as defined in the introduction. The literature review allowed the development of research hypotheses, which were subsequently demonstrated in Sections 3 and 4 of the paper.

An interesting econometric model was built to study the connection between the factors contributing to the increase of microplastic water pollution. Following the implementation of this model at the OECD database level, proposals for improving public policies in the field of combating water pollution caused by microplastics were carried out.

The novelty of the econometric model and public policy proposals for decreasing water pollution caused by microplastics are the strengths of this scientific approach. The novelty of the approach lies in linking chemical elements with economic and social impacts at a regional level. The model is entirely unprecedented and is in no way an adaptation or update of an existing model. The public policy proposals in this area were also innovative.

This scientific work encountered difficulties, including the lack of official statistical information on water pollution caused by microplastics and the lack of a unified approach and common regulations at an international level.

The main limitation of this paper is the relatively small number of indicators used in the analysis. The authors propose to expand the number of indicators analysed and the statistical basis of observations through international collaboration, at least at the academic level, in a future scientific approach on the same topic.

**Author Contributions:** Conceptualization, V.M.A., R.V.I., M.L.Z., C.I., P.L.G. and M.C.; methodology, C.I., P.L.G., R.V.I., M.L.Z. and V.M.A.; validation, V.M.A., R.V.I., M.C. and M.L.Z.; formal analysis, C.I., M.C. and P.L.G.; investigation, C.I., R.V.I., P.L.G., M.C. and M.L.Z.; resources, C.I., P.L.G. and V.M.A.; data curation, V.M.A., C.I. and R.V.I.; writing—original draft preparation, R.V.I., V.M.A., M.L.Z., C.I., P.L.G. and M.C.; writing—review and editing, P.L.G.., M.L.Z., M.C. and C.I.; visualization, V.M.A. and C.I.; supervision, C.I. and R.V.I. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Fondo Proserpina S.R.L., grant number 2506/2022, "The Impact of Heavy Metals and Microplastics from Aquatic Organisms on Human Health".

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** The technical support was provided by the Rexdan Research Infrastructure, the infrastructure created through the project An Integrated System for the Complex Environmental Research and Monitoring in the Danube River Area, REXDAN, SMIS code 127065, project co-financed by the European Regional Development Fund through the Competitiveness Operational Programme 2014–2020, contract no. 309/10.07.2020.

**Conflicts of Interest:** The authors declare no conflict of interest.

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