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, titled “Heavy Metals and Metalloids in Food: Current Status, Health Risks, and Mitigation Strategies,” systematically examined the contamination status, dietary intake, and health risks associated with three major heavy metals/metalloids—arsenic (As), cadmium (Cd), and lead (Pb)—in the global food supply. The review synthesized recent findings from Total Diet Studies, national surveys, and epidemiological research to provide an updated assessment of metal and metalloid concentrations in various food categories, patterns of population exposure, and the key food sources contributing to overall intake. The article also evaluated the effectiveness of intervention and mitigation strategies across the food chain, from agricultural practices to breeding low-accumulation crop cultivars and dietary changes. Emphasis was placed on the implications for vulnerable populations, such as infants, children, and pregnant women, and on comparing national and international regulatory guideline values for these toxicants.
Who was reviewed?
The review encompassed studies and data from diverse populations worldwide, with a focus on both the general population and vulnerable groups, including infants, children, pregnant women, and the elderly. Dietary exposure assessments and health risk evaluations were drawn from multi-country Total Diet Studies (e.g., from China, Japan, Chile, European nations, and the US), as well as targeted surveys in hotspots with high environmental contamination. The review also considered populations specifically at risk due to regional contamination (e.g., communities near mining/smelting sites, or those relying on rice from regions with high groundwater arsenic). The literature synthesized included epidemiological studies, risk assessments, and intervention trials.
Most important findings
| Critical Points | Details |
|---|---|
| Food as a major exposure pathway | For As, Cd, and Pb, dietary intake—especially from rice, cereals, seafood, vegetables, and cocoa—is the predominant exposure route in most populations, surpassing water or air in many contexts. |
| Vulnerable populations at higher risk | Infants, children, and pregnant women often have dietary intakes of As, Cd, and Pb at or above health-based guidance values, increasing their risk for neurotoxicity, developmental effects, and carcinogenicity. |
| Geographical and food-category variation | Seafood (especially seaweed and some shellfish) has the highest total As, though usually as less-toxic organic forms. Rice accumulates more As and Cd than other cereals, with significant geographical variation in inorganic As (iAs) and toxic methylated species. Cocoa and shellfish are notable Cd sources, and vegetables/tea can be major Pb contributors. |
| Metal speciation matters | In seafood, most As is organic (less toxic), but certain rice and seafood products contain highly toxic species like inorganic As and dimethylmonothioarsenate (DMMTA), the latter being more cytotoxic than iAs. Standard testing may underreport these forms. |
| Health-based guidance values and dietary intakes | Most general population exposures are below international tolerable intake limits, but many individuals—especially in high-consumption or contaminated regions—exceed these thresholds. European, Asian, and Bangladeshi populations show particularly high exposure to iAs and Cd from rice and cereals. |
| Health risks and population differences | Chronic exposure, even below regulatory limits, is associated with cancer (As), kidney damage (Cd), and neurodevelopmental toxicity (Pb). Children and women are often more susceptible to adverse effects. |
| Effectiveness of mitigation strategies | Liming, biochar application, water management, and breeding low-accumulating crop varieties are effective at reducing metal accumulation in food, while dietary diversification decreases individual risk. |
| Regulatory and monitoring gaps | Current food safety monitoring may not capture local contamination hotspots or account for all toxic species; more sensitive and comprehensive testing is needed for certification purposes. |
Key implications
The review underscores that food is the dominant source of toxic metal and metalloid exposure for most populations, making rigorous food-based monitoring and certification essential. Heavy Metal Tested and Certified (HTMC) programs must address the complexity of speciation, geographical variation, and vulnerable population intake, and integrate mitigation strategies across the food chain to reduce health risks.
Citation
Zhao D, Wang P, Zhao FJ. Toxic Metals and Metalloids in Food: Current Status, Health Risks, and Mitigation Strategies. Curr Environ Health Rep. 2024;11:468–483. doi:10.1007/s40572-024-00462-7.
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.
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.
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.
