Assessment of Metal Accumulation in Medicinal Plants and Their Soil in District Kamber-Shahdadkot, Sindh, Pakistan

Abstract

The current study was carried out to investigate the physicochemical properties, major elements such as Na, K, Ca, and Mg, and heavy metals like Zn, Fe, Cu, Cd, Pb, Ni, Co, and Mn in medicinal plants and their soil from the district of Kamber-Shahdadkot, Sindh, Pakistan. Five plant samples were collected from the study area and divided into five different parts: root, stem, leaf, seed, and flower. Five soil samples were collected from the same location from a 90 cm-deep ditch. Samples were prepared using acid digestion and analyzed using a flame atomic absorption spectrophotometer (FAAS). Multivariate statistical analyses, including correlation coefficient analysis, principal component analysis, cluster diagrams, and Piper diagrams, were conducted for better interpretation of the data. The concentrations of Na, K, Mg, and Ca in plants varied from 368 to 2,480 mg/kg, 866 to 1,349 mg/kg, 455 to 1,530 mg/kg, and 1,840 to 17,360 mg/kg, respectively, while heavy metals varied as follows: Fe (10.96 to 1,115.2 mg/kg), Mn (0-59.04 mg/kg), Cu (0-68.4 mg/kg), Cr (0-7.68 mg/kg), Pb (0.32-25.28 mg/kg), Zn (0-56.28 mg/kg), and Ni (0.88-8.40 mg/kg). The trace element values varied from plant to plant and also among different plant parts. The correlation and principal component analyses indicated that the major parameters showed strong positive loadings with each other, and the Piper diagram indicated that calcium is the predominant cation. The present study compares the major and trace metals in medicinal plants and their associated soils. The physicochemical results of the soil samples indicated variations from place to place due to differences in soil quality across locations.