Elemental characterization of medicinal plants of the Sundarban by INAA and AAS techniques: health risk assessments and statistical analysis

This study evaluates essential and toxic element contents in three widely used medicinal plants ( Acanthus ilicifolius , Avicennia officinalis , and Xylocarpus mekongensis ) of the Sundarban mangrove ecosystem and the possible health risks through the consumption of these plants. Total concentrations of 20 chemical elements (Al, As, Br, Ca, Cd, Ce, Co, Cr, Fe, K, La, Mn, Na, Pb, Sb, Sc, Sm, Th, V, and Zn) were determined by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS) techniques. The determined concentrations of the elements were compared with available WHO permissible limits which indicate that the average concentration of Zn in A. ilicifolius (41.2 ± 10.1 mg/kg) was higher than that of the permissible WHO limit (27 mg/kg). The average concentrations of Cr in A. ilicifolius (3.35 ± 0.37 mg/kg) and X. mekongensis (4.02 ± 2.30 mg/kg) were also higher than that of the WHO permissible limit (2 mg/kg). However, the average daily intake of the toxic elements was below the maximum tolerable daily intake (MTDI) values. The target hazard quotient (THQ) values were also within the permissible limit (THQ < 1). The elemental transfer factors and pollution index for the medicinal plants were determined and statistical analyses were used to clarify the elemental correlations in the studied plants. Therefore, this study will give valuable information to the public about the elemental contents and health risks due to consumption of the medicinal plants.