Metal(loid) concentrations, bioaccessibility and stable lead isotopes in soils and vegetables from urban community gardens

• Published in: Chemosphere (Oxford) Vol. 305; p. 135499
• Main Authors: Hiller, Edgar, Pilková, Zuzana, Filová, Lenka, Mihaljevič, Martin, Špirová, Veronika, Jurkovič, Ľubomír
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2022
• Subjects: Bioaccessibility; Community garden; Human health risk assessment; Metal(loid)s; Soil; Stable lead isotopes; Community garden; Soil; Bioaccessibility; Stable lead isotopes; Metal(loid)s; Human health risk assessment
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.135499

Community gardens are “green oases” of recent cities with many benefits for human society. From a human health perspective, these benefits can be damaged by chemical contamination of soil and cultivated vegetables. Using geochemical approaches, this study characterised (i) total metal(loid) concentrations in soils and two commonly grown vegetables in urban community gardens (Bratislava, Slovakia), (ii) gastrointestinal bioaccessibility using a modified physiologically based extraction test (PBET), and (iii) stable lead (Pb) isotopes in order to identify sources of metal(loid)s, solubilisation in the human body and migration of Pb from soil to vegetables. While some soils could be considered contaminated when compared to the Slovak legislation for agricultural soil, the bioaccessibility of metal(loid)s did not exceed 20% in the intestinal phase, with the exception of cadmium (Cd). Tomatoes and lettuce contained low total and bioaccessible concentrations of metal(loid)s, being safe for people who consume their own grown vegetables. There were differences in Pb isotope composition among bulk soils, vegetables and bioaccessible Pb, with less radiogenic Pb being preferentially mobilised. Statistical methods considering the compositional nature of the geochemical data and the enrichment factor (EF) distinguished well metal(loid)s of natural origin (As, Co, Cr, Fe, Mn, Ni, V) from those with anthropogenic contributions. This research has shown the usefulness of integrating different methodologies to better understand the geochemistry of metal(loid)s in urban soils with their highly diversified sources. [Display omitted] •Several metal(loid)s were studied in community garden soils and vegetables.•Metal(loid) bioaccessibility in intestine lower than in stomach, excepting As, Cu, Sb.•Bioaccessibility of several metal(loid)s in soil correlated negatively to total Fe/Mn.•Stable lead isotopes in soils differed from vegetables and bioaccessible pools.•No human health risk from exposure to metal(loid) in soils and vegetables.