• bioavailability
• P. americana
• plant uptake
• R. sativus
• rare earth elements
• soil

This thesis analyses the presence of rare earth elements (REEs) in soils of urban and mining origin, with reference to the sites of Parco della Pellerina (Turin, Piedmont) and Boccheggiano (Grosseto, Tuscany). The study evaluated the absorption capacity and partitioning of rare earth elements (REEs) in two plant species, Phytolacca americana and Raphanus sativus. The plants were grown in microcosms in a controlled environment and treated with citric acid and EDTA, chelating agents able to increase the bioavailability of REEs.
The results showed significant discrepancies between the two soil types. The mining soil had a higher concentration of bioavailable REEs, whereas the urban soil offered more favourable conditions for plant growth. Phytolacca americana showed a good ability to uptake and translocate REEs, particularly La, Pr and Y, while R. sativus showed a diversified distribution of elements, being mainly limited to the roots (La, Pr, Ce, Dy, Nd, Gd, Sm).
Citric acid proved effective in increasing the levels of REEs in R. sativus, while in P. americana the most efficient agent was EDTA. During the trials, an innovative digital phenotyping approach was implemented, providing a real-time monitoring of plant morphophysiological responses to treatments.
This study gives a significant contribution to gaining a deeper understanding of the presence and effects of REEs, assessing possible risks to the environment and human health and complementing the current available information.