Intermediate Topic 1058 of 1102 Biochemistry, Environment & Industry

Heavy Metal Pollution

Lead, mercury and cadmium accumulate in food chains.

Practise Biochemistry, Environment & Industry All Biochemistry, Environment & Industry topics

In-depth explanation of Heavy Metal Pollution

Heavy metals such as lead, mercury, cadmium and arsenic are toxic elements released by mining, smelting, industry, batteries and old plumbing. They are not biodegradable, so they persist in soils and sediments for centuries. Metal ions bind to sulfhydryl and other groups in enzymes and proteins, disrupting their function and damaging the nervous system, kidneys and bones. They accumulate in organisms and magnify through food chains. Remediation uses chemical precipitation, ion exchange, adsorption on activated carbon or biochar, and phytoremediation with metal-accumulating plants.

Going deeper: Heavy Metal Pollution

Key ideas: Metals like lead, mercury, cadmium, arsenic and chromium are toxic at low concentrations, are not degraded and bind thiol groups of enzymes. Examples: Minamata disease from methylmercury, itai-itai from cadmium, lead lowering IQ, Cr(VI) carcinogenic. Remediation: precipitation as hydroxide or sulfide, ion exchange, adsorption, phytoremediation.

Common mistakes and connections: Mistake: calling any metal heavy metal by density; the term is used loosely for toxic metals. Organic forms like methylmercury are more toxic and biomagnify. Speciation (As3+ versus As5+, Cr3+ versus Cr6+) changes toxicity. Links to bioaccumulation, precipitation and Ksp.

Visualization of Heavy Metal Pollution

Densities of toxic heavy metals. Unlike organic poisons they do not degrade, so they persist in soil and sediment and build up in organisms. The interactive lesson shows this as a live animation or chart.

Worked example and use case

Itai-itai disease in Japan was caused by cadmium contamination of rice from mining runoff.

Frequently asked questions about Heavy Metal Pollution

What is Heavy Metal Pollution?

Lead, mercury and cadmium accumulate in food chains.

Is Heavy Metal Pollution a beginner, intermediate or advanced topic?

Heavy Metal Pollution is a intermediate topic in Biochemistry, Environment & Industry. It builds on the vocabulary of beginner topics in this area.

What should I learn before Heavy Metal Pollution?

Study these earlier topics in Biochemistry, Environment & Industry first: Eutrophication, Biochemical Oxygen Demand, Dissolved Oxygen.

What comes after Heavy Metal Pollution?

The next topics in Biochemistry, Environment & Industry are Pesticides and Bioaccumulation.

Can I practise Heavy Metal Pollution with quizzes?

Yes. The interactive lesson includes a self-check question on Heavy Metal Pollution, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.

Where Heavy Metal Pollution fits in Biochemistry, Environment & Industry

Heavy Metal Pollution is topic 83 of 127 in Biochemistry, Environment & Industry.