## 5 Conclusions  
Soils with low heavy metal pollution (as in this study) are approved for agricultural use in the production of crops, but not those directly consumed. Following the principles of human and animal health safety, constant monitoring of such soils and plants grown there is recommended. It is closely connected with food security and the potential transport of heavy metals via the food chain to humans. The presented findings underlined the potential utilization of soils with elevated amounts of Cu for agricultural purposes to produce crops, which are not directly consumed by humans. However, continuous monitoring of the actual heavy metal contamination in soil, as well as metal concentrations in crops, is essential and necessary for the simultaneous application of chemical immobilizing methods. The conducted studies confirmed the applicability of immobilizing agents (compost and fly ash) introduction into the soil with elevated Cu contents. In this study, Cu and Zn were analyzed and their contents in amelina and oat were significantly reduced in soils enriched with either compost or fly ash. The positive influence of compost and fly ash was expressed in the case of bioavailability amounts of Cu and Zn as well as their BCF\({}_{\text{B}}\), because these values significantly decreased in comparison to the control conditions. Despite the fact that under the influence of the applied soil additives the total content of Cu and Zn increased in relation to their amounts in the control soil, the calculated concentration coefficients (BCF\({}_{\text{T}}\)) for the soil fertilized with compost (TI) and fly ash (TII) were lower compared to the values calculated for the control soil (T0). The EDI and HRI values calculated for Cu and Zn individually for amelina and oat decreased significantly in the case of plants grown in the soil with the applied immobilizing agents compared to the values obtained for the control plants. The findings connected with EDI and HRI data showed that amelina and oat are safe as potential food products. The Cu and Zn amounts theoretically consumed with oat flakes or amelina oil by humans do not pose any potential health risk. The lack of significant differences between compost and fly ash in relation to the efficacy of Cu and Zn immobilization indicates that the practical usefulness of these substances is similar, and in practice the selection of either of the two depends only on their local availability. In light of the obtained findings, the utilization of bioconcentration factors, estimated daily intake, and health risk indices should be considered helpful tools in assessing the influence of Cu and Zn on their accumulation in plants as a result of probable transfer from soil, as well as qualitative appraisal of food products in terms of potential health risks.  
Conceptualization, M.J.; methodology, M.J.; software, E.B.; validation, M.J. and E.B.; formal analysis, E.B.; investigation, M.J.; resources, M.J.; data curation, E.B.; writing--original draft preparation, M.J.; writing--review and editing, M.J. and E.B.; visualization, E.B.; supervision, M.J.; project administration, M.J.; funding acquisition, E.B. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This study was partially funded by a grant from the Rector of the Poznan University of Technology (grant number 0213/SIGR/2154). The publication was co-financed within the framework of the Ministry of Science and Higher Education Program as \"Regional Initiative Excellence\" in years 2019-2022, Project No. 005/RID/2018/19.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.