Heavy Metals Interaction in Soil-Plant System of Carmagnola cannabis Strain

Evolution in the legislation of Cannabis in Lebanon regarding production and consumption of related products for medicinal and recreational uses is leading to emerging regulations regarding the potency and cannabinoid profiles. On 21 April 2020, the Parliament passed a law legalizing cannabis cultivation for medical use. The objective of this work was to estimate the heavy metals accumulation in the soil-plant system and to help the governmental regulatory body on having also into account the impurities of metals within their rules of regulation. The impurity content of hyperaccumulating metals (zinc, chromium, arsenic, manganese, cadmium, barium, aluminum, iron, cobalt, nickel, copper and lead) was evaluated by inductively coupled plasma atomic emission spectrometry (ICP-OES) taking into account the pseudototal and mobilizable concentrations of the elements in the rhizosphere of plants and the total concentrations of their aerial parts and spikes from allotments in Kropia region-Athens, Greece. The main physicochemical assets of topsoil samples such as pH (7.99±0.05) and organic matter content (rich), the X-ray crystallography test (basically quartz, albite and vermiculite) and soil texture determination test (basically sandy loam soil) were also determined. The concentrations of most of our studied elements in soil plant system samples were recorded below or around the plant reference material concentrations used in our analysis. Results showed also that Al was highly toxic in soil and plant samples. In the plant samples, the arsenic was nearly absent and the lead, nickel, copper, chromium and cadmium contents were less than those found in the plant reference material. In the soil samples, only copper and zinc concentrations were found to be within the accepted ranges. The maximum transfer factor is found in lead (Tf – Pb = 0.8223). Average transfer factor of elemental concentrations showed that heavy metals were not easily translocated in the soil-plant system (0.0514±0.0032). In addition, hemp plants that are considered as "hyper-accumulators" showed very acceptable results for industrial and other uses.