Evaluation of heavy metals accumulation potential of hemp (Cannabis sativa L.)

Abstract

Heavy metals accumulation in crops and soils poses a significant threat to the human health. A study was carried out in 2016 in order to assess hemp (Cannabis sativa L.) ability to accumulate heavy metals and to reveal its possibility as a phytoaccumulator or phytostabilizer. Two soil types from Croatia were used in experimental pots: Gleysoils (alkaline soil) and Stagnic Luvisol (acid soil). Majority of the varieties accumulated more heavy metals in roots than in above-ground biomass. Removal of Cd, Ni, Pb, Hg, Co, Mo and As was higher in acid soil. Potential ability for phytostabilization was observed in alkaline soil in order Cu>Cr> Cd>Mo>Hg>Zn>Ni>Co>As>Pb, while for acid soil in order Zn>Cd>Cr>Ni>Hg>Cu> Mo>As>Co>Pb. Some varieties exhibited a translocation coefficient (TC) more than 1 and shown the ability of hyper-accumulation for Zn, Hg, Mo and Cd. Higher accumulation of heavy metals in some varieties could lead to their general application for phytoaccumulation of heavy metals from polluted soils.

Macro and Trace Elements in Hemp (Cannabis sativa L.) Cultivated in Greece: Risk Assessment of Toxic Elements

“…The concentration of macro and trace elements accumulated by cannabis varies, depending on several factors, such as the type and the variety of the plant, the geographical origin (soil) where the plant grew, the application of pesticides and fertilizers, the drying methods of the hemp, and the storage conditions (Galic et al, 2019).…”

“…As cannabis can accumulate both natural and anthropogenic contaminants of high concern during its growth, it is considered a potential source of risk for human health (Fu et al, 2018;Craven et al, 2019;Atapattu and Johnson, 2020). In particular, in cannabis, trace and macro elements can build up, including also toxic ones, mainly via the soil and water in which it grows, or through the deposition of fertilizers, pesticides, and fungicides that are commonly applied to crops and contain such elements (Galic et al, 2019). The variety of the plant, harvesting time, geographical origin, topography, and duration of the exposure to the contaminants are factors playing an essential role in the accumulation of elements in the cannabis plant (Arpadjan et al, 2008;Nagajyoti et al, 2010).…”

The Remediation of Agricultural Land Contaminated by Heavy Metals

“…A necessary resource availability and a low human impact on the environment during remediation are the basic factors of a high phytoremediation potential for the sake of a wide implementation in Croatia, especially for the sake of a remediation of soils contaminated with Cd. The recent increase of hemp cultivation in Croatia could also bear future importance for the phytostabilization of soil Cd and Cr, being successfully applied to both the acidic and alkaline soils in Croatia (Galić et al, 2019). A phytostabilization using hemp and a chemical immobilization using straw are currently some of the most viable remediation strategies for a prevalent problem of Cr soil contamination in Croatia.…”

Global Impact of Non-essential Heavy Metal Contaminants in Industrial Cannabis Bioeconomy

“…Exposure to air pollutants, domestic e uents, direct root absorption from the earth's crust, cross-contamination during the drying process, and post-processing adulteration with additives to enhance market value are the main sources of non-essential heavy metals (HMs) in cannabis products (Busse et al 2008). Decision-making in industrial cannabis production must integrate the following: (1) that one-third of the global arable lands are contaminated (Tripathi et al 2016) with HMs such as lead (Pb), chromium (Cr), arsenic (As), zinc (Zn), cadmium (Cd), copper (Cu), mercury (Hg), and nickel (Ni), (2) that Cannabis species have a high propensity to bioaccumulate HMs from their growing medium (Galić et al 2019;Husain et al 2019;Linger et al 2005), and (3) that there is no market value for cannabis product contaminated with Hg, Cd, As, and Pb above the permissible threshold. This cohort of elements (As, Pb, Cd, Hg, Cr) are often with unknown biological purposes and toxic at higher concentrations in plants (Fig.…”

“…1; Hajar et al 2014). While de ciency and excessive uptake of bene cial elements in cannabis is phenotypically expressed, hyperaccumulation of HMs in the roots and above-ground tissues is associated with no detectable morphological changes (Galić et al 2019;Linger et al 2005). This suggests that the cultivation of cannabis should be accompanied by HMs monitoring at all growth stages.…”