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 reviewed?
This review article synthesizes field‐tested strategies and outcomes for heavy metal-contaminated soil remediation across mining sites, tailings disasters, and agricultural land. It contrasts physical containment (capping, encapsulation), chemical stabilization (lime, phosphates, biochar), and plant-/microbe-based approaches, emphasizing real-world performance rather than laboratory proxies. The authors catalog methods commonly used in actual contamination events, summarize efficiencies and trade-offs, and track emerging tools such as nanoremediation and agromining. A central conclusion supported by case studies from U.S. Superfund mines, the Iberian Pyrite Belt, Aznalcóllar (Spain), and Germano (Brazil), is that combined strategies, especially physical containment paired with assisted phytoremediation, show the best field-scale results for heavy metal-contaminated soil remediation. The paper also highlights the growing agricultural problem, where “gentle remediation options” stabilize contaminants while maintaining productivity.
Who was reviewed?
The evidence base spans remediation campaigns at active and abandoned mines, river valleys affected by tailings dam failures, and agricultural districts with long-term inputs of fertilizers, manures, and wastewater. Mining examples include Formosa and Iron King (USA), where compost-assisted phytostabilization improved pH, microbial diversity, dust control, and plant establishment; Portuguese and Spanish sites where amendments and native excluder species stabilized contaminants and reduced bioavailability; and South African tailings where indigenous grasses accumulated substantial metal loads. Tailings disasters Xingping (China), Aznalcóllar (Spain), and Germano (Brazil) illustrate emergency removal, pH neutralization, amendment management, and ecosystem monitoring. Agricultural case work emphasizes cultivar selection (low-accumulating crops), immobilizing amendments, and intercropping to limit food-chain transfer.
Most important findings
| Critical point | Details |
|---|---|
| Combined remedies outperform single methods | Lime, composts, biochar, and phosphates can quickly raise pH and immobilize metals, but mismanagement may mobilize elements (e.g., Sb) or over-alkalinize soils; careful selection and periodic re-application are needed as effects can be temporary. |
| Biological approaches must be site-conditioned | Phytostabilization with native, metal-tolerant excluders and plant growth–promoting microbes reliably reduces bioavailability and erosion; hyperaccumulator-led phytoextraction alone is slow and biomass-limited in highly contaminated soils. |
| Amendment choice and pH control are pivotal | Vegetated covers and compost amendments at tailings sites reduced horizontal dust flux and fine particulates—the fraction with the highest inhalation risk—delivering early exposure reductions even before long-term soil recovery. |
| Dust and particulate control is an immediate health win | Vegetated covers and compost amendments at tailings sites reduced horizontal dust flux and fine particulates—the fraction with highest inhalation risk—delivering early exposure reductions even before long-term soil recovery. |
| Agricultural “GRO” strategies protect yield and safety | Gentle remediation options—immobilizing amendments, pollutant-excluding cultivars, and intercropping—lower transfer to edible parts while improving soil structure and microbiology; success hinges on cultivar selection and ongoing ecotoxicological monitoring. |
| Monitoring must be long-term and multi-metric | Post-action surveillance of pH, bioavailable fractions, enzyme activity, microbial diversity, plant tissue burdens, and dust is essential; some areas remained bare or above background years after large interventions, underscoring the need for sustained programs. |
| Emerging tools show promise but need field validation | Nanomaterials (e.g., nZVI, TiO₂ NPs) can immobilize or enhance uptake; agromining/biomass valorization can offset costs, yet both remain largely pilot-scale and require environmental risk evaluation and economic proofs. |
Key implications
For regulators, primary regulatory impacts include endorsing combined containment–amendment–phytomanagement as default for high-burden sites; certification requirements should mandate pH control, dust suppression, and demonstrable reductions in bioavailable fractions; industry applications favor native excluders with compost or lime and rigorous monitoring; research gaps persist in long-term amendment stability, nanomaterial ecotoxicology, and scalable phytoextraction; practical recommendations prioritize site-specific remedy trains, cultivar screening, biomass management, and multi-year verification within HTMC audits.
Citation
Sánchez-Castro I, Molina L, Prieto-Fernandez M-A, Segura A. Past, present and future trends in the remediation of heavy-metal contaminated soil—Remediation techniques applied in real soil-contamination events. Heliyon. 2023;9:e16692. doi:10.1016/j.heliyon.2023.e16692
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.
