Quality assessment of new constructed technosols: Key findings on their biogeochemical and environmental characteristics

Technosols might be of a great potential to be used for urban greening. Furthermore, this research intended to evaluate nine different technosol combinations and check for the best yielded results to implement in a large scale mesocosm. The application of such materials could significantly boost the circular economy by preserving natural soil and recycling the continuous flows of urban discharges such as construction and demolition wastes (CDW). However, such application cannot be carried out without biogeochemical, physical and agronomical characterization. The focus of the study was mainly on trace metals distribution and potential impacts. Results showed that concentrations of trace metals, of most tested mixes are within Italian standards. Therefore, the technosols are not phytotoxic. Regarding environmental and ecological risk, no metal contamination was found. However, the subsequent human health risk assessment revealed some concerns particularly with children's exposure to such materials with a high hazard index and cancer risk. While the results might be overestimated it is still advisable to apply the studied materials in urban areas (urban greening) with certain precautions. Nevertheless, for other applications, such as site rehabilitation, these materials might be appropriate.