Heavy Metals Accumulation in the Edible Vegetables of Lebanese Tabbouli Salad

Nowadays soil contamination practices create hazardous environment impact that is a vital issue to prevent heavy metals from their integration in the food chain. Plant species selected for this study were the ingredients of the traditional Lebanese salad, Tabbouli, composed of parsley and lemon that were selected from Damour, olive and onion from Ghazir, peppermint and tomato from Akkar and bulgur, to fulfill all the requirements for the assessment of the major physicochemical properties and the contamination levels in vegetables from soils with heavy metal elements. The major physicochemical properties of topsoil including pH, organic matter content method (LOI) and texture showed that studied soils were almost neutral pH of 7.09 with an organic matter content of 4.22% and a texture of sandy loam. Concentration ranges of As, Cu, Fe, Zn, Mn, Ni, Ba, Cd, Co, Cr, Pb and P in studied soil samples were determined and assessed by Inductively Coupled Plasma Optical Emission Spectroscopy, following aqua regia digestion and weak acetic acid digestion. Also, similar measurements on studied plant samples following microwave assisted digestion by HNO3/H2O2 were determined and transfer factors from soils to vegetables were accordingly calculated because of their health risk. Results showed that concentrations of most of studied elements in soil and plant samples were recorded above the permissible limits set by International standards for agricultural soils and by International standards for vegetables FAO/WHO. Furthermore, soil to plant transfer is the major path way of human exposure to potentially toxic elements contamination. Good manufacturing and agricultural practices and safety measurements have to be strictly adapted.