Ćaćić et al. 2019 - heavy metals in hemp roots, stems, and leaves

Ćaćić and coauthors evaluated metal uptake by four hemp (Cannabis sativa L.) varieties grown in pots with two Croatian soil types. The paper is not a market-basket food survey; it is supply-chain botanical evidence showing how Cd, Cu, Ni, Pb, Zn, Cr, Hg, Co, Mo, and As partition across hemp roots, stems, and leaves under different soil pH conditions. Plant-tissue values are routeable as botanical context, while soil concentrations and phytoremediation metrics should remain context for cultivation conditions.

Key numbers

Table 3 reports plant metal concentrations in mg/kg dry weight. The table below preserves the source units and summarizes the exact four-variety ranges within each soil type and plant part; no values are converted.

Highest Table 3 values by element and plant part include alkaline-root Cr 272.1 mg/kg in variety II, alkaline-root Ni 99.4 mg/kg in variety II, acid-root Zn 688.6 mg/kg in variety III, acid-leaf Zn 440.7 mg/kg in variety II, acid-root Pb 14.6 mg/kg in variety IV, acid-root Cd 2.82 mg/kg in variety I, acid-root As 13.6 mg/kg in variety IV, and acid-root Hg 0.08 mg/kg in variety I.

Table 2 soil context values, in mg/kg, were: alkaline soil Cd 0.3, Cu 19.02, Ni 77.74, Pb 13.65, Zn 78.21, Cr 113.5, Hg 0.04, Co 10.24, Mo 0.2, As 8.53; acid soil Cd 0.18, Cu 17.5, Ni 27, Pb 18.25, Zn 46.25, Cr 18.5, Hg 0.04, Co 12.25, Mo 0.2, As 9.25. The paper’s contamination-level calculation flagged alkaline-soil Ni at 155.5% of the Croatian maximum allowable concentration and Cr at 141.9%; all acid-soil values were below 100% of the listed MAC.

Table 4 reports biological adsorption coefficient (BAC) patterns. The highest printed BAC was Cd 16.1 for variety I roots in acid soil; the highest Zn BAC was 14.9 for variety III roots in acid soil. The authors summarize potential phytostabilization ability as Cu>Cr>Cd>Mo>Hg>Zn>Ni>Co>As>Pb in alkaline soil and Zn>Cd>Cr>Ni>Hg>Cu>Mo>As>Co>Pb in acid soil.

Table 5 reports translocation coefficients. TC was generally below 1, except for Zn, Hg, and Mo in some alkaline-soil varieties and Cd, Zn, Hg, and Mo in some acid-soil varieties. The highest printed TC values were Mo 5 for variety III in alkaline soil, Mo 2 for all acid-soil varieties, Cd 2.58 for variety IV in acid soil, Zn 1.69 for variety II in acid soil, and Hg 1.33 for variety II in alkaline soil.

For above-ground biomass removal, the authors report Zn removal up to 27.1 kg/ha, with lower removals for Cr (0.15-0.35 kg/ha), Ni (0.08-0.73 kg/ha), and Cu (0.14-0.52 kg/ha).

Methods (brief)

The 2016 pot experiment used two Croatian soils: alkaline Gleysol from Raša in Istria and acid Stagnic Luvisol from near Daruvar. Four hemp varieties in the EU catalogue were planted in three replications per soil type: Fedora 17, Fibrol, Futura 75, and Santhica 27. Soil samples were air-dried, milled, sieved to less than 2 mm, and extracted with aqua regia for ICP-OES measurement. Roots, stems, and leaves were sampled separately at the end of the experiment, oven-dried at 70 °C to constant weight, milled, microwave-digested, and measured by atomic absorption spectrometry under Croatian/ISO methods cited by the paper. The source reports total elemental measurements; Hg is treated as total Hg, As as total As, and Cr as total Cr, with no methylmercury, inorganic arsenic, or Cr-VI speciation.

Implications

Certification: The paper contributes crop-tissue evidence for hemp and cannabis-derived botanical supply chains, but only as experimental cultivation context. It should not be pooled with retail supplement or food occurrence values without separating root, stem, leaf, soil pH, and pot-experiment conditions.

Courses: The study is a useful case for distinguishing soil-remediation metrics (BAC, TC, kg/ha removal) from product occurrence values. The same numbers can support phytoremediation conclusions and still be unsuitable as market-basket supplement evidence.

App: The source can inform herbal-botanicals supply-chain context for hemp-derived ingredients, especially the root-vs-leaf partitioning of Cd, Pb, tAs, and tHg.

Wiki pages this source may touch

• supplements-botanicals-herbs
• herbal-botanicals
• cadmium
• lead
• arsenic-total
• mercury-total
• nickel
• chromium
• copper
• zinc

Verification notes

• Identity checks on 2026-06-09: DOI 10.5513/JCEA01/20.2.2201, raw handle MFK_10.5513-jcea01-20.2.2201, and cite-key cacic2019-hemp-heavy-metals returned no existing source page hits before creation.
• Author metadata conflict: the extracted PDF title page renders the first author as Marija GALIĆ, but the article running header says Ćaćić et al., the corresponding email is mcacic@agr.hr, and the Journal of Central European Agriculture landing page lists Marija Ćaćić. The cite_key and frontmatter use the journal landing-page/running-header form.
• All Key numbers ranges were calculated directly from Table 3 in /tmp/hmi-june9-007.txt extracted with pdftotext -layout; spot checks include Cd acid-root values 2.82/0.6/0.88/0.24, Pb acid-root values 6.66/12.3/9.32/14.6, and Zn acid-root values 349.4/427.8/688.6/69.5.
• Speciation check: the paper reports total elements only. Frontmatter records tAs and tHg; no iAs, MeHg, or Cr-VI is claimed.
• The source is B-tier because it is a controlled pot/phytoaccumulation experiment rather than a retail food, supplement, or personal-care occurrence survey.
• No product brand names are present. Variety names are cultivars, not sampled commercial brands, and are retained as study design variables.
• Missing slug note: there is no dedicated hemp or cannabis ingredient slug in the current taxonomy snapshot; frontmatter uses the broad existing [[ingredients/herbal-botanicals]] slug and records hemp/cannabis only as matrix descriptors.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.