Metal(loid) concentrations, bioaccessibility and stable lead isotopes in soils and vegetables from urban community gardens
Edgar Hiller, Zuzana Pilková, Lenka Filová, Martin Mihaljevič, Veronika Špirová, Ľubomír Jurkovič
Chemosphere
Urban Farm DB summary
A 2022 study of urban community gardens in Bratislava, Slovakia, measuring total metal(loid) concentrations in soils and in two commonly grown vegetables (tomato and lettuce), gastrointestinal bioaccessibility using a modified physiologically based extraction test (PBET), and stable lead isotopes. Although some soils would count as contaminated against Slovak agricultural-soil legislation, bioaccessibility in the intestinal phase did not exceed 20% except for cadmium, and tomatoes and lettuce contained low total and bioaccessible metal(loid) concentrations, making them safe for people eating their own produce. Lead isotope composition differed between bulk soils, vegetables and the bioaccessible fraction, with less radiogenic lead preferentially mobilised, and enrichment factors separated naturally derived elements (As, Co, Cr, Fe, Mn, Ni, V) from those with anthropogenic contributions. The result is a counterweight to blanket alarm about urban soil metals: exceeding a total-concentration threshold is not the same as a dose that reaches the human body.