This review traces how lead, cadmium, mercury and inorganic arsenic enter and bioaccumulate in the food chain, explains their mechanisms of toxicity, and stresses that risk depends on chemical species and daily dose.
Authors
- Mititelu M, Neacșu SM, Busnatu ȘS, Scafa-Udriște A, Andronic O, Lăcraru AE, Ioniță-Mîndrican CB, Lupuliasa D, Negrei C, Olteanu G. , Toxics. 2025
What was studied
The review titled “Assessing Heavy Metal Contamination in Food: Implications for Human Health and Environmental Safety” examines how toxic heavy metals and metalloids enter the food supply and what they do once consumed. It identifies the main human-made sources and the pathways by which metal pollutants spread, with an emphasis on chemical speciation and bioavailability. It traces how lead (Pb), cadmium (Cd), mercury (Hg) and the inorganic arsenic (As) species As(III) and As(V) move into ecosystems, bioaccumulate in the food chain, and compromise food safety and nutritional value. The review also describes the biochemical mechanisms of toxicity and considers mitigation strategies.
Who was studied
This is a narrative review of published research, not a sampling study, so no new food samples or human subjects were analysed. It draws on the literature on environmental sources, food-chain transfer, exposure routes and toxicological mechanisms of heavy metals and metalloids, and it considers the consequences for public health and agricultural sustainability.
Most important findings
| Critical Points | Details |
|---|---|
| Species and dose determine toxicity | Heavy metals and metalloids vary in toxicity with their molecular form and daily dose, so identifying the chemical species is essential for judging their effect on health and the environment. The authors stress precise terminology: toxicity is tied to dose and chemical species rather than to the element as such. |
| Sources and pathways | The review identifies the main anthropogenic sources and dissemination pathways of metal pollutants and how they reach ecosystems and food. |
| Food-chain bioaccumulation | Toxic metal species such as Pb, Cd, Hg, As(III) and As(V) infiltrate ecosystems and bioaccumulate within the food chain, compromising both the safety and the nutritional value of food. |
| Mechanisms of harm | Toxic metals displace essential ions from enzyme active sites and transport proteins by competitive binding, induce oxidative stress through reactive oxygen species, and disrupt metabolic pathways and signalling cascades. Together these contribute to both chronic and acute health conditions. |
| Mitigation | The authors call for integrated, multidisciplinary strategies to reduce these risks, improve ecosystem stability and protect long-term food security. |
Key implications
The review supports a food-safety approach that looks beyond total element content to the chemical form of each metal, its bioavailability and the daily dose consumers actually receive. For testing and certification programs such as the Heavy Metal Tested and Certified (HMTC) program, this underlines the value of knowing where contamination comes from, measuring the metals of greatest concern (lead, cadmium, mercury and inorganic arsenic), and interpreting results against dose-based reference values. Because the paper is a review, it does not report new contamination measurements or compliance rates.
Citation
Mititelu M, Neacșu SM, Busnatu ȘS, Scafa-Udriște A, Andronic O, Lăcraru AE, Ioniță-Mîndrican CB, Lupuliasa D, Negrei C, Olteanu G. Assessing Heavy Metal Contamination in Food: Implications for Human Health and Environmental Safety. Toxics. 2025;13(5):333. doi:10.3390/toxics13050333
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 for which no safe blood lead level in children has been identified. It contaminates food, consumer goods and drinking water, and exposure is linked to cognitive deficits in children, adverse pregnancy outcomes such as preterm birth and low birth weight, 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.
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.
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.