[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › Heavy metal poisoning # Heavy metal poisoning Lead, mercury, arsenic, cadmium and iron: where exposure comes from, what each metal damages and when chelators are used. Updated Nov 2, 2026 Metals are not broken down by the body, so they accumulate. Each one has a typical source and target organ. Treatment always starts by stopping the exposure; chelating agents, which bind the metal so it can be excreted, are added for significant poisoning. ## Key points - Lead has no known safe blood level; children absorb more of it and suffer lasting harm to brain development. - Methylmercury from fish and mercury vapour from artisanal gold mining are the main mercury hazards; the fetus is most vulnerable. - Inorganic arsenic in drinking water causes skin lesions and cancers over years; acute poisoning causes vomiting, diarrhoea and neuropathy. - Iron overdose is a classic childhood poisoning; deferoxamine binds iron, and activated charcoal does not. - Chelators (edetate calcium disodium, dimercaprol, succimer, deferoxamine) never replace removing the source. ## Lead Lead comes from old paint, mining, smelting, battery recycling, lead pipes, some ceramic glazes and traditional remedies. Young children absorb several times more than adults and put dust in their mouths. In children it impairs brain development, attention and learning and causes anaemia; in adults it raises blood pressure and damages the kidneys. A blood smear can show basophilic stippling. Lead stored in bone can reach the fetus during pregnancy. ## Mercury Elemental mercury vapour is inhaled (gold mining, broken instruments); inorganic salts damage the gut and kidneys; methylmercury builds up in large predatory fish and crosses into the brain and the fetus. Effects include tremor, memory loss, headache, kidney injury and harm to development. The Minamata Convention, named after a Japanese bay where methylmercury in seafood poisoned a community, aims to phase out mercury uses. Artisanal gold mining, which uses mercury, is an important source in mining regions. ## Arsenic and cadmium Inorganic arsenic occurs naturally in some groundwater. Years of exposure cause pigment changes and thickened skin on the palms and soles, and cancers of the skin, bladder and lung. Acute poisoning brings vomiting, abdominal pain and diarrhoea, then numbness and tingling. Cadmium, an industrial metal, mainly damages the kidney. ## Iron Iron tablets, including prenatal vitamins, are a dangerous ingestion in children. Vomiting and diarrhoea come first, and serious cases develop a high anion gap metabolic acidosis. Activated charcoal does not bind iron; whole-bowel irrigation can clear tablets, and deferoxamine binds iron for excretion, sometimes turning the urine reddish. ## Chelating agents - Edetate calcium disodium: lead poisoning, often together with dimercaprol when levels are high or symptoms present; it can damage the kidney, so urine output is watched. - Dimercaprol: injected chelator for lead, arsenic and mercury. - Succimer: oral chelator used mainly for lead in children. - Deferoxamine: acute iron poisoning and transfusional iron overload. - Removing the source of exposure comes first in every case. ## Memory aid Lead hits the Little ones' brains; Mercury goes to the Mind and the womb; Arsenic marks the skin. ## Test yourself Think of the answer, then tap the question to see it. ## Why are young children more vulnerable to lead? They absorb more of an ingested dose than adults, put dust and soil in their mouths, and their developing brain is easily harmed. ## What is the main dietary source of methylmercury? Contaminated fish and shellfish, especially large predatory fish. ## Why is activated charcoal not useful in iron overdose, and what antidote binds iron? Charcoal does not bind iron; deferoxamine chelates it for excretion. ## Why is urine output monitored during treatment with edetate calcium disodium? The drug can damage the kidneys, and treatment must stop if urine output falls severely. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/topics/heavy-metal-poisoning/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Example drugs - [Sodium calcium edetate](https://durgical.com/en/pharmacology/sodium-calcium-edetate/) - [Dimercaprol](https://durgical.com/en/pharmacology/dimercaprol/) - [Succimer](https://durgical.com/en/pharmacology/succimer/) - [Deferoxamine](https://durgical.com/en/pharmacology/deferoxamine/) - [Ferrous sulfate](https://durgical.com/en/pharmacology/ferrous-sulfate/) ## Connections ## Related classes 2 - [Chelating agents](https://durgical.com/en/pharmacology/classes/chelating-agents/) - [Specific antidotes](https://durgical.com/en/pharmacology/classes/specific-antidotes/) [← All of pharmacology](https://durgical.com/en/pharmacology/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Lead poisoning](https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health) (World Health Organization, 2026); [Mercury](https://www.who.int/news-room/fact-sheets/detail/mercury-and-health) (World Health Organization, 2026); [Arsenic](https://www.who.int/news-room/fact-sheets/detail/arsenic) (World Health Organization, 2026); [DailyMed - EDETATE CALCIUM DISODIUM injection](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=710a2c8c-3620-4f6f-b8fc-fb19ab9e9f22) (DailyMed (U.S. National Library of Medicine), 2026); [DailyMed - DEFEROXAMINE- deferoxamine mesylate injection, powder, lyophilized, for solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d91e16df-8daa-4cd2-86a2-273eaa2446e0) (DailyMed (U.S. National Library of Medicine), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/topics/heavy-metal-poisoning/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/topics/heavy-metal-poisoning/