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 comprehensive review examined heavy metal toxicity mechanisms and heavy metal toxicity treatment, with particular emphasis on environmental sources, bioaccumulation pathways, and organ-specific toxicity patterns. The authors analyzed how heavy metals, including lead, mercury, cadmium, arsenic, chromium, nickel, copper, zinc, antimony, manganese, thallium, and cobalt, enter the environment through both natural and anthropogenic sources, accumulate in biological systems, and cause damage through various molecular mechanisms. The review synthesized evidence on neurotoxicity, nephrotoxicity, hepatotoxicity, carcinogenicity, immunological toxicity, cardiovascular toxicity, skin toxicity, reproductive toxicity, and genotoxicity. Additionally, the study evaluated treatment approaches using natural products and nanotechnological interventions, examining how compounds like curcumin, quercetin, and various plant extracts counteract metal-induced oxidative stress, inflammation, and cellular damage.
What was reviewed?
The authors conducted a comprehensive literature review spanning multiple databases to examine experimental studies on heavy metal toxicity and treatment options. The review encompassed both in vitro and in vivo studies using various animal models (primarily rats, mice, and guinea pigs) as well as human cell lines and clinical observations. The analysis included studies on bioaccumulation patterns in food crops, particularly vegetables grown in contaminated soil, and the transfer of heavy metals through the food chain. The review also evaluated emerging nanotechnology-based approaches for heavy metal detection and removal from water and food sources, including metal oxide nanoparticles, carbon nanotubes, graphene derivatives, and magnetic nanoparticles.
Most important findings
| Aspect | Details / Findings |
|---|---|
| Heavy Metal Toxicity – Lead | Methylmercury bioaccumulates via the aquatic food chain, causing neurological damage; hair mercury correlates with atherosclerosis and cardiovascular disease risk. |
| Heavy Metal Toxicity – Cadmium | Antioxidant activity, anti-inflammatory effects, modulation of apoptotic pathways, and enhancement of endogenous antioxidant enzymes. |
| Heavy Metal Toxicity – Mercury | Methylmercury bioaccumulates via the aquatic food chain, causes neurological damage; hair mercury correlates with atherosclerosis and cardiovascular disease risk. |
| Common Mechanisms | Oxidative stress and reactive oxygen species generation are shared pathways across tissues. |
| Natural Product Interventions – Curcumin | Protects against arsenic-induced dopaminergic changes, cadmium nephrotoxicity (reduces kidney injury molecule-1), and lead hepatotoxicity; effective at 50–400 mg/kg in animal models. |
| Natural Product Interventions – Quercetin | Protects against nickel-induced hepatic dysfunction and mercury-induced kidney damage; effective at 20–250 mg/kg doses. |
| Other Natural Compounds | Grape seed proanthocyanidin extract and lutein reduce arsenic-induced reproductive toxicity via Nrf2 signaling. |
| Mechanisms of Protection | Antioxidant activity, anti-inflammatory effects, modulation of apoptotic pathways, enhancement of endogenous antioxidant enzymes. |
Key implications
This review provides key evidence for heavy metal certification programs, establishing critical dose-response relationships and highlighting that most human exposure occurs through food. It finds that chronic low-dose cadmium exposure increases cardiovascular mortality risk, necessitating stricter safety thresholds. The contamination of food crops is shown to depend on soil, plant genotype, and agricultural practices, with mineral fertilizers being a significant source. For certification testing, nanotechnology-based methods offer superior sensitivity and selectivity. However, a major limitation is that most data come from animal studies, indicating a need for caution when applying these findings to human safety standards.
Citation
Mitra S, Chakraborty AJ, Tareq AM, et al. Impact of heavy metals on the environment and human health: Novel therapeutic insights to counter the toxicity.Journal of King Saud University – Science. 2022;34(3):101865. doi:10.1016/j.jksus.2022.101865
Heavy metal toxicity occurs when metals such as lead, cadmium, arsenic, mercury, nickel, tin, aluminum, and chromium accumulate beyond detoxification capacity, causing oxidative stress, cellular dysfunction, and chronic disease. The HMTC program sets stricter limits to protect vulnerable populations and ensure product safety.
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.
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.
