Investigation of heavy metal analysis on medicinal plants used for the treatment of skin cancer by traditional practitioners in Pretoria

Abstract

Abstract The use of medicinal plants for the treatment of diseases, including cancer, is acknowledged and accepted in many African nations. Heavy metal contamination of plant materials poses a potential health risk, particularly for populations that are already vulnerable. This study determine the levels of heavy metals in medicinal plant samples used for treatment of skin cancer and evaluate the health risk caused by heavy metals to the adult population in Pretoria, South Africa using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of metals were as follows; As (< 0.2–1.04 ± 0.026), Cd (0.02 ± 0.00026–0.167 ± 0.006), Pb (0.38 ± 0.01–2.27 ± 0.05), Cr (5.31 ± 0.21– 26.9 ± 3.96) mg/kg and Hg which were lesser than 0.02 mg/kg. The mean concentrations of all analyzed heavy metals are above permissible limit except for Hg which are lower than the permissible limit. The Hazard Quotient (THQ) was less than 1 for all the heavy metals, suggesting that there is no obvious non-carcinogenic health risks associated with the consumption of these medicinal plants for now even though the prolonged use may result in health risks. The ingestion route was identified as the primary contributor to the overall risk by the health index (HI) values in the present study were more than 1, indicating that the combined effects of the heavy metal contaminants present in a particular herbal preparation pose health risk in the long term. Our findings support the need for close monitoring of potential heavy metals concentrations in medicinal plants given to patients from herbal shops.