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 research article conducted a comprehensive risk assessment of heavy metal pollution in agricultural soils surrounding industrial enterprises in Lanzhou, China, with direct relevance to heavy metal certification programs such as the Heavy Metal Tested and Certified (HMTC) initiative. The focus keyphrase, “heavy metal pollution in agricultural soils,” is central as the study quantifies contamination levels, spatial variability, ecological risks, and health impacts across multiple industrial sectors. Utilizing indices such as the geo-accumulation index (Igeo), Nemerow composite pollution index (PN), potential ecological risk index (RI), and US EPA-based health risk models, the research systematically evaluated the presence and risk of eight heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, Hg, As) in surface soils. Special attention was given to identifying contamination hotspots, understanding exposure pathways, and differentiating risks for adults and children, providing a robust foundation for risk-based soil management and potential regulatory standards.
Who was studied
The study focused on agricultural soils in the vicinity of 16 industrial enterprises and one sewage-irrigated area in Lanzhou, China, encompassing six specific sectors: waste disposal, pharmaceutical manufacturing, chemical manufacturing, petrochemical, metal smelting, and mining, plus a sewage-irrigated zone. A total of 334 surface soil samples were systematically collected from these zones, representing a broad cross-section of farmland environments exposed to industrial emissions. Human health risk assessment models were applied to hypothetical populations—adults and children—using standardized exposure parameters relevant for regulatory frameworks. This dual focus on environmental and human health endpoints ensures the study’s outcomes are highly applicable for both environmental certification and public health risk management.
Most important findings
| Critical Points | Details |
|---|---|
| Contamination hotspots identified | The sewage-irrigated zone (SIZ) and pharmaceutical manufacturing zone (PMZ) showed 100% strong pollution in samples, especially for Hg and Cd. |
| Severity and distribution of key metals | Mercury (Hg) exhibited the highest accumulation and risk (Igeo=1.89, critical risk in 41.32% of samples), with cadmium (Cd) also significant (Igeo=0.61, strong risk in 32.63%). |
| Overall pollution status | All sampled areas showed moderate to strong pollution by the Nemerow index, with 67.37% of samples in the strong category. |
| Exposure pathways and health risk | Oral ingestion was the dominant exposure route. While non-carcinogenic and adult carcinogenic risks were within acceptable limits, children had oral exposure carcinogenic risk (CR=1.33×10⁻⁴) exceeding safety thresholds. |
| Regulatory and certification implications | Despite high concentrations, differences in toxicological parameters (RfD, SF) mean high levels of Hg and Cd do not always directly equate to proportional health risks, highlighting the need for nuanced, risk-based certification. |
| Recommendations for control and monitoring | Hg and Cd should be prioritized for control in SIZ and PMZ, especially regarding exposure prevention for children. Remediation and stricter irrigation water quality controls are recommended. |
Key implications
This study shows that heavy metal pollution in agricultural soils near industrial zones in Lanzhou is severe, especially for Hg and Cd. For a heavy metal certification program, risk-based standards are essential, prioritizing monitoring and remediation in high-risk areas and protecting vulnerable populations, particularly children.
Citation
Duan K, Li Y, Yang W, Lin Y, Rao L, Han C. Risk Assessment of Heavy Metal Pollution in Agricultural Soils Around Industrial Enterprises in Lanzhou, China: A Multi-Industry Perspective Promoting Land Sustainability. Sustainability. 2025;17:5343. doi:10.3390/su17125343
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.
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.
Aluminum is a pervasive metal found in a wide range of consumer products, from food packaging and cookware to medications and personal care items. Although often overlooked, aluminum exposure can accumulate over time, posing long-term health risks, especially to vulnerable populations like infants, children, and individuals with kidney conditions.
Nickel is a widely used transition metal found in alloys, batteries, and consumer products that also contaminates food and water. High exposure is linked to allergic contact dermatitis, organ toxicity, and developmental effects, with children often exceeding EFSA’s tolerable daily intake of 3 μg/kg bw. Emerging evidence shows nickel crosses the placenta, elevating risks of preterm birth and congenital heart defects, underscoring HMTC’s stricter limits to safeguard vulnerable populations.
Mercury (Hg) is a neurotoxic heavy metal found in various consumer products and environmental sources, making it a major public health concern. Its regulation is critical to protect vulnerable populations from long-term health effects, such as neurological impairment and cardiovascular disease. The HMTC program ensures that products meet the highest standards for mercury safety.
Arsenic is a naturally occurring metalloid that ranks first on the ATSDR toxic substances list. Inorganic arsenic contaminates water, rice and consumer products, and exposure is linked to cardiovascular disease, cognitive deficits, low birth weight and cancer. HMTC’s stringent certification applies ALARA principles to protect vulnerable populations.
