Bioaccumulation of Potentially Toxic Elements in Tilia tomentosa Moench Trees from Urban Parks and Potential Health Risks from Using Leaves and Flowers for Medicinal Purposes

Abstract

Potentially toxic element (PTE) contamination in medicinal plants, particularly those growing in urban environments, can cause human health issues. Therefore, this study evaluated trace element accumulation and translocation patterns (As, Cr, Cu, Ni, Pb, Sr, and Zn) in the aboveground tissue of common Tilia tomentosa Moench, often used as a medicinal plant, sampled in Belgrade’s urban parks (Zemunski Park, Park Blok 63, and Park Topčider). Our results indicated that this species exhibits the ability to accumulate and translocate PTEs, particularly Cu, in its aboveground parts. It was found that the levels of Cu and Sr in flowers were within the toxic range for plants, indicating a potential risk in using T. tomentosa flowers from Park Topčider for medicinal purposes. The maximum Estimated Daily Intake of Ni from the consumption of leaves and flowers of plants growing in two parks (Zemunski Park and Park Topčider) exceeded the corresponding Provisional Tolerable Daily Intake. Additionally, the Carcinogenic Risk calculated for Cr present in flowers was above the USEPA limit (3.021 x 10-3), indicating possible adverse effects on human health and a carcinogenic risk from ingesting tea prepared from T. tomentosa flowers from Park Topčider. Our research underlines how crucial it is to cautiously use medicinal tree species growing in urban parks in residential areas.