Heavy metals: toxicity and human health effects

Area of Science:

• Environmental Science
• Toxicology
• Biochemistry

Background:

• Heavy metals are persistent environmental pollutants originating from the Earth's crust.
• Human exposure occurs through inhalation, ingestion of contaminated food/water/soil, and the food chain.
• Bioaccumulation of heavy metals leads to diverse toxic effects across multiple organ systems.

Purpose of the Study:

• To comprehensively review the mechanisms of heavy metal toxicity.
• To discuss the health effects associated with exposure to specific heavy metals.
• To outline available heavy metal detoxification methods.

Main Methods:

• Literature review of heavy metal toxicity mechanisms.
• Analysis of biochemical pathways affected by heavy metals.
• Compilation of data on heavy metal-induced diseases and their treatments.

Main Results:

• Heavy metals interfere with antioxidant systems (glutathione, antioxidant enzymes) and signaling pathways.
• Toxicity mechanisms include oxidative stress generation (ROS, Fenton reaction), essential metal displacement, and disruption of cellular processes (apoptosis, cell growth).
• Specific metals (Al, Cd, As, Hg, Pb, Cr) are linked to gastrointestinal, pulmonary, kidney, reproductive, neurodegenerative, cardiovascular, and various cancers.

Conclusions:

• Heavy metal toxicity is multifaceted, involving oxidative stress, disruption of essential metal functions, and interference with cellular processes.
• Exposure to heavy metals poses significant risks for a wide range of chronic and degenerative diseases.
• Chelation therapy offers a potential strategy for mitigating heavy metal toxicity.