Accumulation of Heavy Metals and Their Genotoxic Potential in Medicinal Plant Verbacsum speciosum Schrad.

Abstract

Background: Nowadays, the contamination of soil, water, and plants by heavy metals (HMs) presents a notable environmental problem. Methods: Lead (Pb) and zinc (Zn) levels in soil and Verbacsum speciosum populations were measured using atomic absorption spectroscopy, and meiosis in pollen mother cells (PMCs) was examined through the squash technique to evaluate genotoxic effects. Results: The results showed that Pb and Zn concentrations in the soil and, roots, and aboveground portions of all Verbacsum speciosum populations within the mining area exceeded permissible thresholds significantly. Particularly, the contaminated soil displayed average Pb and Zn concentrations of 3527.4±0.7 and 1671.4±0.5 mg/kg, respectively. The roots of Verbacsum speciosum plants closest to the mine exhibited the highest levels of Pb and Zn, measuring 204±0.05 mg/kg and 570±0.16 mg/kg, respectively. Additionally, the above-ground parts of the plants showed Pb and Zn concentrations of 312±0.12 mg/kg and 519±0.17 mg/kg, respectively. Moreover, the transfer factor (TF) for both Pb and Zn was found to be above one, indicating substantial accumulation of these metals in the above-ground portions. The presence of Pb and Zn also resulted in abnormalities during meiosis. As the distance from the mine increased, a decrease in the occurrence of meiosis abnormalities and an increase in the meiotic index (MI) were observed. Conclusion: These results highlight the potential risks to human health posed by industrial wastewater and the natural presence of HMs in soil. The ability of these metals to accumulate in plants and interfere with their meiosis underscores the importance of addressing and mitigating these hazards.