Evaluation of the Amount of the Accumulation of Some Heavy Metals in a Number of Commonly Used Medicinal Plants and Their Risk in Children and Adults in Sistan and Baluchestan Province in 2021: A Laboratory Study

The use of medicinal plants is increasing among people and the presence of pollutants such as heavy metals in them can affect the health of consumers. Therefore, the purpose of this study was to determine the amount of accumulation of some heavy metals in a number of commonly used medicinal plants and to evaluate their risk in children and adults.

In this laboratory study, 5 types of medicinal plants, 4 samples of each type, were collected from different regions of Sistan and Baluchestan province in the spring of 2021. The samples were prepared and acid digested in the laboratory and were evaluated in terms of the concentration of Cd, Pb, Cu, As, and Hg by inductively coupled plasma-optical emission spectrometry (ICP-OES) and flame atomic absorption spectroscopy (FAAS). Data was analyzed by using Kolmogorov-Smirnov, one-sample t-test, and one-way ANOVA, and the risk of each of these metals was estimated due to their consumption in children and adults.

The average amount of heavy metals in different types of plants was very variable and lower than the permissible level for both children and adults. Target hazard quotient (THQ) for each of the metals and Hazard Index (HI) for all metals, in all types of medicinal plants, were significantly lower than the permissible level (THQ/HI=1).

Medicinal plants of Sistan and Baluchestan province have low levels of heavy metal contamination and their consumption is completely safe for children and adults.