Heavy metals in the body — how can you get rid of them?

Aim of the study: The heavy metal lead (Pb) is a major environmental and occupational hazard. Epidemiological studies have demonstrated a strong association between lead exposure and the presence of chronic kidney injury.

Results: However, calcium disodium EDTA chelation in lead exposure is controversial due to the potential for adverse effects such as acute tubular necrosis. Therefore, we investigated the available randomized controlled trials assessing the renoprotective effects of calcium disodium EDTA chelation therapy. Our meta-analysis shows that calcium disodium EDTA chelation therapy can effectively delay the progression of chronic kidney disease in patients with measurable body lead burdens reflected by increasing the levels of estimated glomerular filtration rate (eGFR) and creatinine clearance rate (Ccr). There appears to be no conclusive evidence that calcium disodium EDTA can decrease proteinuria.

Aim of the study: Exposure to heavy metals is common. This exposure is related to environmental contamination of air, water and soil, occupational exposure, accumulation in food, tobacco, and other factors.

Results: In patients with a history of myocardial infarction, the Trial to Assess Chelation Therapy study showed that EDTA chelation decreased the likelihood of cardiovascular events, particularly in patients with diabetes. However, heavy metal levels were not measured in this study. It is clear that more research is needed in this area. There is also a need to more frequently consider and test for the possibility of cadmium and lead toxicity in patients with increased risk, such as those with hypertension, diabetes mellitus, and chronic renal disease.

Aim of the study: Exposure to cadmium and lead is widespread, and is related to environmental contamination, occupational sources, food, tobacco and other consumer products. Lower socioeconomic status increases the risk of heavy metal exposure and the diseases associated with cadmium and lead toxicity.

Results: In patients with a history of myocardial infarction, the Trial to Assess Chelation Therapy (TACT) study showed that Ca EDTA chelation decreased the likelihood of cardiovascular events, particularly in diabetics. Ca EDTA chelation administered carefully at lower dosage (<50 mg/kg per week) is generally safe. In the past, acute renal failure associated with much higher dosage was reported. We suggest that the preponderance of the evidence favors a more activist approach towards diagnosis and possible intervention in heavy metal toxicity.

Aim of the study: The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due to the inconvenience of parenteral administration, their own toxicity and tendency to increase the neurotoxicity of several metals.

Results: In copper overload, DMSA appears to be a potent antidote, although d-penicillamine is still widely used. In the chelation of iron, the thiols are inefficient, since iron has higher affinity for ligands with nitrogen and oxygen, but the new oral iron antidotes deferiprone and desferasirox have entered into the clinical arena. Comparisons of these agents and deferoxamine infusions are in progress. General principles for research and development of new chelators are briefly outlined in this review.

Aim of the study: Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces.

Results: 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents) or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.

Aim of the study: Mercury is a widespread heavy metal with potential severe impacts on human health. Exposure conditions to mercury and profile of toxicity among humans depend on the chemical forms of the mercury: elemental or metallic mercury, inorganic or organic mercury compounds.

Results: Treatment using chelating agents is recommended in case of symptomatic acute mercury intoxication; sometimes it improves the clinical effects of chronic mercury poisoning. Although it is currently rare to encounter situations of severe intoxication, efforts remain necessary to decrease the mercury concentration in the environment and to reduce risk on human health due to low level exposure (dental amalgam, fish contamination by organic mercury compounds…). In case of occupational exposure to mercury and its compounds, some disorders could be compensated in France. Clinicians should work with toxicologists for the diagnosis and treatment of mercury intoxication.

Aim of the study: Widespread exposure and bioaccumulation of toxic heavy metals have increased the incidence of metal poisoning, particularly in children. Although chelation therapy can remove toxic metals, current drugs are limited by toxicity and side effects, restricting treatment to severe cases.

Results: Dex-DOTA also showed excellent colloidal stability, no cytotoxicity, and improved cell survival following metal exposure. In C. elegans, the conjugate was nontoxic and mitigated heavy metal-induced toxicity. These findings establish Dex-DOTA as a stable, selective, and biocompatible chelator with strong potential for safer systemic treatment of heavy metal poisoning.

Aim of the study: The incidence of copper sulfate poisoning varies across different regions. It is relatively rare in Western countries but more prevalent in South Asian nations, accounting for approximately 40% of all heavy metal poisoning cases.

Results: It is relatively rare in Western countries but more prevalent in South Asian nations, accounting for approximately 40% of all heavy metal poisoning cases. The majority of affected individuals are rural residents, with a mortality rate ranging from 14% to 36%. Copper sulfate poisoning often leads to gastrointestinal corrosion, intravascular hemolysis, hemolytic anemia, methemoglobinemia, and acute multi-organ dysfunction, often resulting in death due to delayed treatment. In June 2024, we successfully managed a case of acute oral copper sulfate poisoning through early interventions, including gastric lavage and sodium dimercaptopropane sulfonate (Na-DMPS) for copper chelation, resulting in the patient's recovery and discharge after 1 week.

Aim of the study: Lead exposure remains a significant yet under-recognised public health concern in the UK, particularly among vulnerable paediatric populations. Its non-specific, multisystemic involvement and rare neurological presentations make recognition and timely treatment of lead poisoning especially challenging.

Results: This case highlights the importance of considering lead toxicity in unexplained encephalopathy or refractory seizures in children, with early recognition to prevent irreversible neurological sequelae.