In a combined endeavour with the collaboration project Heavy Metal City-Zen (https://cityzenboden.com/about/), samples from the Viennese urban gardens Tigergarten and Paradeisgartl were analysed for their elemental and isotopic composition. The outcomes of the ICP-MS analyses were published in Environmental Science and Pollution Research by Simone Trimmel, Stefan Wagner, Laura Feiner, Maria Feiner, Daniela Haluza, Rebecca Hood-Nowotny, Ulrike Pitha, Thomas Prohaska, Markus Puschenreiter, Philipp Spörl, Andrea Watzinger, Elisabeth Ziss and Johanna Irrgeher: https://doi.org/10.1007/s11356-024-34240-7
Following the finding of elevated Pb contents in soil and plant samples from Paradeisgartl and in one plant sample from Tigergarten in Heavy Metal City-Zen, the overarching aim of this follow-up investigation was the assessment of measures which can be taken to reduce human intake of potentially toxic elements from garden products. The skin, pulp and seeds of tomato fruits, as well as the peel, bulb, root tips and leaves of radishes were processed separately to investigate to which extent contaminants accumulate in specific plant tissues. While there was only minor variation in the elemental contents between tomato fruit parts, in the root tips and in particular in the leaves of radishes, the highest contents of potentially toxic elements such as Cd, Tl and Pb was observed.
Washing of lettuce leaves was found to significantly reduce the contents of potentially toxic elements such as Be, Al, V, Ni, Ga and Tl. Additionally, compost amendments led to promising results, with reduced Zn, Cd, and Pb levels in radish bulbs, demonstrating an effective measure for mitigating soil contamination. Pb isotope ratios in soil and spinach leaf samples taken in the previous study were assessed to trace Pb uptake from soils into food. A direct linkage between the Pb isotopic signatures in soil and those in spinach leaves was observed, underscoring their effectiveness as tracers of Pb sources in the environment.
