Multiple potentially toxic elements in urban gardens from a Brazilian industrialized city

Abstract

Urban agriculture should be promoted as long as the food produced is safe for consumption. Located in the metropolitan region of São Paulo-Brazil, Santo André has intense industrial activities and more recently an increasing stimulus to urban gardening. One of the potential risks associated to this activity is the presence of potentially toxic elements (PTEs). In this study, the concentration of PTEs (As, Ba, Cd, Co, Cu, Cr, Ni, Mo, Pb, Sb, Se, V and Zn) was evaluated by soil (n=85) and soil amendments (n=19) in urban gardens from this municipality. Only barium was above regulatory limits in agricultural soil, although enrichment of all elements was observed. A multivariate statistical approach was applied and indicated two groups of elements with strong in uence of the petrochemical complex located in this region. However, carcinogenic, and non-carcinogenic risks were not observed. Soil amendments were identi ed as a possible source of contamination for Ba, Zn and Pb and for pathogenic bacteria. Besides that, the occurrence of antimicrobial resistance suggests some soil management practices are necessary.

Home food gardening in modern cities: advances, issues, and future perspectives

“…Urban soils in industrialized cities can contain high levels of contaminants, such as heavy metals and organic pollutants (e.g., petroleum hydrocarbons, antibiotics, microplastics), which can be emitted from sources like automotive exhaust. These contaminants have the potential to accumulate in the human body when consuming food grown in polluted soils, leading to various side effects, including carcinogenic risks (Gao et al, 2015;Manucharova et al, 2021;Nematollahi et al, 2022;Zhu et al, 2023;Lange et al, 2024). While food contamination from polluted urban soil can be addressed through the adoption of substrate culture or hydroponics, it is important to note that toxic heavy metals present in the atmosphere of densely populated areas may pose a threat to the safety of home-grown food (Izquierdo-Díaz et al, 2023).…”