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?
The focus keyphrase “heavy metal accumulation in Ghanaian foodstuffs” is central to this study, which systematically assessed the accumulation of heavy metals and a metalloid in foodstuffs cultivated around the Tarkwa area of Ghana, an active gold mining region. Specifically, the investigation measured concentrations of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in agricultural soils and two staple food crops—cassava (Manihot esculenta) and plantain (Musa paradisiaca). The study also evaluated the transfer efficiency of these metals from soil to food crops using the bioconcentration factor (BCF) and assessed the associated human health risk through the target hazard quotient (THQ), with a particular focus on possible exposure due to dietary intake. The intention was to elucidate the extent and impact of heavy metal accumulation in Ghanaian foodstuffs in communities exposed to mining-related contamination, providing critical insights for food safety and heavy metal certification programs.
Who was studied?
The study population comprised food crops and soils sampled from thirteen communities surrounding Tarkwa, Ghana—a region characterized by intensive gold mining operations and agricultural activity. Sixty soil samples and sixty-five foodstuff samples (33 cassava and 32 plantain) were collected randomly from local farms. Local dietary habits were considered for health risk assessment, with estimated daily intakes for adults (cassava: 601 g/day, plantain: 369 g/day) and children (cassava: 400 g/day, plantain: 200 g/day). The analysis thus indirectly included local residents as a modeled population for health risk assessment, focusing on both children and adults, as their exposure was estimated based on the measured contaminant levels in staple foods and their typical consumption patterns. This selection ensures relevance to real-world exposure scenarios for communities in mining-impacted regions of Ghana.
Most important findings
| Critical Point | Details |
|---|---|
| Elevated Pb in Cassava | 30% of cassava samples exceeded Codex Alimentarius Commission standards for lead (Pb), with some communities (Techiman, Wangarakrom, Samahu, Tebe) showing the highest levels. THQ values for Pb in these communities were above 1 for both adults and children (children especially at risk), indicating significant potential health hazards from cassava consumption. |
| Bioconcentration Factor (BCF) and Metal Transfer | Nickel (Ni) had the highest BCF (2.0–2.2), indicating strong transfer from soil to both food crops. Other metals, including Pb, Zn, and Cu, showed lower BCFs. No significant correlation was found between soil pH, organic matter, and BCF, suggesting that plant metal uptake is not strongly influenced by these soil parameters in the studied context. |
| Overall Metal Distribution | Concentration order in cassava: Zn > Ni > Cu > Pb > Cr > Co > As > Cd ≈ Hg. In plantain: Zn > Ni > Cu > Cr > As > Pb > Co > Cd ≈ Hg. Most metals were present at lower levels in foodstuffs than in soil, but notable exceptions were observed for Ni, with higher concentrations in foodstuffs. |
| Health Risk Assessment | The THQ for Pb in cassava from several communities exceeded 1, especially for children, signifying unacceptable health risks. Other metals (As, Cd, Hg) in both cassava and plantain were below risk thresholds. Plantain generally posed a lower risk compared to cassava for all metals assessed. |
| Regulatory Implications | The findings highlight the need for continuous monitoring, strict regulation, and possible interventions (such as food processing or source mitigation) to protect consumers, especially children, from chronic Pb exposure in mining regions. These results are directly relevant for heavy metal certification programs that seek to ensure food safety in contaminated regions. |
Key implications
This study demonstrates that heavy metal accumulation in Ghanaian foodstuffs, particularly cassava, poses a significant health risk from lead exposure in certain mining-affected communities. For heavy metal certification programs, these results stress the necessity for routine testing, enhanced regulatory oversight, and targeted risk management to protect public health, especially children.
Citation
Bortey-Sam N, Nakayama SMM, Akoto O, Ikenaka Y, Fobil JN, Baidoo E, Mizukawa H, Ishizuka M. Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks. Int J Environ Res Public Health. 2015;12(8):8811-8827. doi:10.3390/ijerph120808811
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.
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.
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.
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.
