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 investigated the effect of boiling on heavy metal and cyanide concentrations in cassava (Manihot esculenta) and cocoyam (Colocasia esculenta) cultivated near a gold mining area in Kade, Ghana. The study specifically evaluated the extent of cadmium (Cd), mercury (Hg), arsenic (As), and cyanide accumulation in these staple crops, both before and after thermal processing, and assessed the associated health risks for consumers. The research aimed to quantify the impact of traditional cooking methods on reducing dietary exposure to these contaminants, thereby informing food safety strategies in mining-impacted regions. Using systematic sampling and robust analytical protocols, the study generated data to guide recommendations for heavy metal certification and public health interventions in communities exposed to mining-related contamination.
Who was studied?
The study focused on cassava and cocoyam crops grown within 2 kilometers of an active gold mining site in Kade, Eastern Region, Ghana. Sampling was conducted across six points, each separated by 50 meters, to capture spatial variability in contamination. These root crops were selected due to their prevalence in the local diet and their significance to food security. The health risk assessment considered exposure scenarios for both adults and children in the surrounding population, reflecting the typical local consumption patterns. Thus, the study is directly relevant to the agricultural communities residing near gold mining operations and indirectly addresses consumers who rely on these staple foods.
Most important findings
| Critical Points | Details |
|---|---|
| Heavy metal & cyanide levels in raw crops | Unprocessed cassava and cocoyam contained measurable levels of Hg (0.301–0.426 mg/kg), As (0.010–0.020 mg/kg), Cd (0.024–0.030 mg/kg), and cyanide (0.301–0.620 mg/kg). All were below WHO food safety standards, though As and Hg levels in raw samples posed potential health risks for children. |
| Effectiveness of boiling | Boiling (thermal processing) reduced Hg by 65%–80%, As by 85%–95%, and Cd by 60%–75% in both crops. Cyanide was significantly reduced, often to undetectable levels, especially in cassava. |
| Health risk assessment | Hazard index (HI) calculations revealed that unprocessed samples, particularly for children, exceeded the safety threshold for As (HI 23.36–25.10) and Hg (HI 2.53–2.39). After cooking, HI values for all contaminants fell below 1 for both adults and children, indicating minimal noncarcinogenic health risk. |
| Spatial variability and monitoring | Although contamination was present, levels varied by sampling location, emphasizing the need for site-specific assessment and regular monitoring in agricultural areas near mining operations. |
| Regulatory and certification relevance | The ability of traditional cooking to reduce contaminant levels supports the inclusion of preparation methods in heavy metal certification protocols and risk communication strategies. |
Key implications
This study demonstrates that while cassava and cocoyam grown near gold mining sites in Ghana can accumulate hazardous heavy metals and cyanide, traditional boiling substantially reduces these contaminants to levels below international safety limits. For heavy metal certification programs, including preparation methods in protocols, is essential to accurately assess dietary risk and ensure consumer safety. Regular site-specific monitoring remains vital in mining-impacted regions.
Citation
Fobi COA, Eshun G, Kwarteng TA, Amponsah AS, Adoma PO. Effect of Boiling on Heavy Metal and Cyanide Concentrations and Associated Health Risks in Cassava and Cocoyam From a Gold Mining Area in Kade, Ghana. Int J Food Sci. 2025;2025:5137953. doi:10.1155/ijfo/5137953
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.
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.
