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 field study examined the phytoremediation properties of sweet potato for the removal and partitioning of lead (Pb), zinc (Zn), and cadmium (Cd) from soils surrounding abandoned lead-smelting tailings in Shymkent, South Kazakhstan. Researchers mapped contamination gradients, quantified soil metals at 5 and 15 cm depths, cultivated sweet potatoes for 133 days on three contaminated household fields and one control site, and measured metal concentrations in tubers and leaves using flame atomic absorption spectrometry. Risk characterization included geoaccumulation (Igeo), contamination factor (Cf), and Hakanson ecological risk indices (Er, RI). Bioconcentration (BCF) and translocation factors (TF) were calculated to evaluate uptake and within-plant movement. A spatial heat-map on page 8 visualizes Pb, Zn, and Cd hotspots near tailings, while Table 5 (page 9) and Table 8 (page 11) provide concentration, BCF, and TF values.
Who was studied?
Three farmstead plots adjacent to the tailings and one distant control plot were studied as environmental “subjects,” with sweet potato (Ipomoea batatas L.) serving as the test organism. Fields differed in proximity and wind exposure to the mine waste, creating gradients in soil contamination that influenced plant uptake. Planting used 25–30 cm stem cuttings placed 7–10 cm deep and grown for 133 days (May–September 2022). Sampling quantified Pb, Zn, and Cd in bulk soil and in two plant compartments, tubers and leaves, enabling calculation of BCF and TF to determine whether the phytoremediation properties of sweet potato align with hyperaccumulation or stabilization behaviors across heterogeneous urban-agricultural conditions.
Most important findings
| Critical point | Details |
|---|---|
| Soil contamination profile | Tailings contained very high Pb (1354.5 mg/kg), Zn (262.9 mg/kg), and Cd (61.08 mg/kg). Adjacent soils spanned Pb 7.76–551.49 mg/kg, Zn 8.25–245.74 mg/kg, and Cd 5.40–19.23 mg/kg; control soils were much lower (Pb 2.20, Zn 3.70, Cd 3.18 mg/kg). Igeo values indicated heavy to extremely high contamination, especially for Zn at Field 3 (Igeo ≈ 11.32 at 5 cm). |
| Ecological risk category | Hakanson indices showed overall moderate comprehensive risk (RI), driven primarily by Cd Er at Field 3, despite large absolute Pb and Zn loads. |
| Plant metal concentrations | In contaminated fields, tuber metals reached Pb 28.7–45.1 mg/kg, Zn 70.0–94.2 mg/kg, and Cd 0–1.80 mg/kg. Leaves reached Pb 2.34–32.5 mg/kg, Zn 8.24–59.4 mg/kg, and Cd up to 2.75 mg/kg. Control tubers had Pb ≈ 0.96 mg/kg and Zn ≈ 38.5 mg/kg; Cd was undetected. |
| Uptake behavior (BCF) | Sweet potato exhibited BCF >1 for Pb and Zn across multiple fields, indicating hyperaccumulation potential. Representative tuber BCFs: Pb 6.36–10.50; Zn 0.85–35.77 (Field-specific). Cd BCFs were <1 (0.08–0.30), signifying limited cd accumulation relative to soil.< td> |
| Translocation behavior (TF) | TF highlighted compartment-specific movement: Cd showed TF >2 at Field 3 (2.31), signaling active shoot transfer when present; Zn TFs were ≤0.63; Pb TFs ranged 0.08–0.95, indicating dominance of tuber/root retention and partial leaf movement under higher exposure. |
| Partitioning trend | Metal affinity followed Zn > Pb > Cd for overall accumulation. Tubers generally contained higher Pb and Zn than leaves, relevant for root-harvested phytoextraction paired with careful biomass handling. |
| Spatial evidence | The page 8 maps (Figure 3) show strongest Pb/Zn/Cd zones closest to tailings; Table 6 (page 10) confirms extreme Igeo classes for Zn and high Igeo for Pb at near-field sites, aligning plant uptake patterns with depositional gradients. |
| Analytical robustness | Calibration curves for Pb, Zn, Cd showed R² ≥ 0.9998 with LODs ~0.06–0.10 mg/L and recoveries ~99–101%, supporting confidence in soil/plant concentration estimates. |
Key implications
For HTMC, primary regulatory impacts include classifying adjacent soils as heavily to extremely contaminated by Igeo, with phytoremediation properties of sweet potato demonstrating hyperaccumulation for Pb and Zn under field conditions. Certification requirements should prohibit edible use of biomass from remediation plots and mandate a chain-of-custody for harvested tubers and leaves. Industry applications include staged phytoextraction to depress bioavailable Pb and Zn in peri-urban farms, supported by periodic BCF/TF verification. Research gaps include cultivar variability, safe biomass end-uses, and Cd behavior under amendments. Practical recommendations prioritize source containment, plot zoning, monitoring at 5–15 cm depths, and documented disposal pathways.
Citation
Toishimanov M, Abilda Z, Daurov D, Daurova A, Zhapar K, Sapakhova Z, Kanat R, Stamgaliyeva Z, Zhambakin K, Shamekova M. Phytoremediation Properties of Sweet Potato for Soils Contaminated by Heavy Metals in South Kazakhstan. Applied Sciences. 2023;13(17):9589. doi:10.3390/app13179589
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.
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.
