Assessing Environmental Risks of Local Contamination of Garden Urban Soils with Heavy Metals Using Ecotoxicological Tests.

Abstract

Heavy metal soil contamination in urban areas poses a significant environmental hazard, particularly in regions with historical or ongoing industrial activities. These areas are often polluted with metals such as Pb, Cu, Cd, and Zn, which can be absorbed by plants and pose risks to both ecosystems and human health. This study investigates soil contamination in urban gardens in Wroclaw, Poland, where elevated levels of trace elements were detected. Standard soil analyses, including macroelement content, granulometry, and trace element concentrations, were performed alongside an ecotoxicological evaluation using an Ostracodtoxkit test. The test evaluates the impact of contaminants on organism growth. An uncontaminated urban garden soil served as a reference. This study revealed that Zn, Cu, Pb, and Cd concentrations in soils exceeded limits permitted by Polish regulations in several soil samples. Despite the high concentrations of total metals, the bioavailable forms of these metals (measured by extraction of 1 M NH₄NO₃ extraction) were significantly lower, highlighting that the total metal content may not fully reflect the environmental risk. Pb was identified as the primary contributor to growth inhibition of test organisms, showing a particularly strong correlation with ecotoxicity. These findings underscore the importance of using ecotoxicological tests to evaluate soil contamination risks.