Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied?
This original experiment quantified heavy metal content in sweet potato produced in soils amended with varying proportions of gold-mine tailings and composted cow manure, with emphasis on cadmium, copper, lead, and zinc. Conducted in a controlled greenhouse pot trial, the study tested whether organic amendments reduce plant uptake or modify translocation of these metals, and whether Ipomoea batatas could serve as a phytoremediation crop in tailings-impacted settings relevant to HTMC thresholds for consumer safety. According to the article’s design and results sections, metal concentrations were measured in roots and shoots by AAS, translocation factors were calculated, and outcomes were interpreted against FAO/WHO limits, generating actionable evidence for certification protocols. Table 1 on page 3 details starting metal burdens in tailings (e.g., Zn ~11,507 mg/kg; Cu ~6,142 mg/kg), underscoring the contamination gradient imposed by treatments, while Figure 3 on page 7 shows translocation factors typically >1, indicating preferential shoot loading.
Who was studied?
The test organism was the orange-fleshed sweet potato clone MZ119, a stable, high-yielding genotype established in Indonesian breeding programs. Growth media combined topsoil with gold-mine tailings from Kertajaya Village, Sukabumi, West Java (Indonesia), at 0%, 30%, 50%, 70%, and 100% (w/w) plus composted cow manure at 0, 250, 500, and 750 g per 10 kg of media. Plants were fertilized uniformly (NPK 5 g/pot), watered to ~60% field capacity, and harvested 18 weeks after planting. Tissues were separated into roots and shoots for heavy-metal analysis, and translocation factors were computed to assess movement from roots to aerial parts. The design directly reflects field-realistic contamination scenarios pertinent to heavy metal content in sweet potato entering supply chains.
Most important findings
| Critical point for HTMC | Details and regulatory relevance |
|---|---|
| Tailings proportion drives uptake | Increasing tailings from 0% to 100% markedly elevated Cd, Cu, Pb, and Zn in plant tissues; 100% tailings produced the highest shoot Cu and Zn, indicating a severe risk when crops are grown on or near tailings. Table 6–8 shows monotonic increases, with Zn in shoots rising by ~1,050–2,936 mg/kg above control and roots up to ~4,580 mg/kg at 100% tailings. This directly signals disqualification for edible certification. |
| Exceedance of food limits | All measured metals in shoots and/or roots exceeded FAO/WHO permissible limits for vegetables (Cd 0.2 mg/kg, Pb 0.3 mg/kg, Cu 73.3 mg/kg, Zn 99.4 mg/kg). The authors explicitly conclude that sweet potatoes grown on contaminated media “may not be used for consumption,” a decisive metric for HTMC. |
| Translocation to edible biomass | Translocation Factor (TF) values for Cd, Cu, Pb, and Zn were generally >1 across treatments, demonstrating preferential accumulation in shoots (Figure 3, p. 7). For certification, TF>1 elevates concern because aerial parts are closer to edible storage roots and indicate strong upward mobility under field conditions. |
| Effect of composted cow manure | Manure decreased Zn accumulation in shoots by ~826–1,678 mg/kg compared with no manure and tended to reduce Cd in shoots as application rate increased; however, Pb often remained high and, in some combinations with heavy tailings, still rose. Thus, organic amendments mitigate some bioavailability but do not ensure compliance with HTMC edible thresholds. |
| Biomass impacts and phyto-use | Gold tailings suppressed root and shoot biomass up to ~98% without manure, while manure partially restored growth on uncontaminated soil. Despite toxicity, the crop’s ability to accumulate Zn>Cu>Pb>Cd supports targeted phytoremediation, not food use, in tailings-affected sites. |
| Metal ranking and matrix chemistry | Accumulation followed Zn>Cu>Pb>Cd; low pH and sulfur in tailings increased metal solubility, enhancing plant uptake. These geochemical drivers explain persistent exceedances and inform site remediation prerequisites before any certification pathway. |
Key implications
For HTMC, the primary regulatory impacts include categorical non-eligibility of crops grown on tailings-impacted soils due to systematic exceedances and TF>1. Certification requirements should mandate site history verification, soil testing, and rejection criteria where tailings are present. Industry applications include using this cultivar for phytoremediation with strict disposal controls. Research gaps include edible root data and field-scale kinetics. Practical recommendations emphasize pre-plant soil screening, amendment efficacy verification, and supply-chain traceability.
Citation
Noviardi R, Karuniawan A, Sofyan ET, Suryatmana P. Heavy metals content in sweet potato (Ipomoea batatas L.) grown on soil contaminated by gold mine tailings with composted cow manure amendment. Journal of Degraded and Mining Lands Management. 2023;10(4):4601-4610. doi:10.15243/jdmlm.2023.104.4601
Heavy metals are high-density elements that accumulate in the body and environment, disrupting biological processes. Lead, cadmium, arsenic, mercury, nickel, tin, aluminum, and chromium are of greatest concern due to persistence, bioaccumulation, and health risks, making them central to the HMTC program’s safety standards.
Cadmium is a persistent heavy metal that accumulates in kidneys and bones. Dietary sources include cereals, cocoa, shellfish and vegetables, while smokers and industrial workers receive higher exposures. Studies link cadmium to kidney dysfunction, bone fractures and cancer.
Lead is a neurotoxic heavy metal with no safe exposure level. It contaminates food, consumer goods and drinking water, causing cognitive deficits, birth defects and cardiovascular disease. HMTC’s rigorous lead testing applies ALARA principles to protect infants and consumers and to prepare brands for tightening regulations.
