Cadmium

Ways Cadmium Is Absorbed by the Human Body

• Inhalation: Cadmium is primarily absorbed through the lungs when inhaled as particulates or fumes, especially in industrial environments or from cigarette smoke. Absorption rates can range from 10% to 50% depending on particle size and solubility
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• Ingestion: Cadmium is absorbed through the gastrointestinal tract, especially from contaminated food and water. The absorption rate is lower (about 3–9%) compared to inhalation, but can be higher in individuals with nutritional deficiencies (e.g., low iron, calcium, or zinc)
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• Skin contact: Absorption through the skin is rare but possible with certain cadmium compounds

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Foods Containing Cadmium

• Grains and cereals: Especially rice and wheat grown in contaminated soil.
• Leafy vegetables: Such as spinach and lettuce.
• Shellfish and seafood: Particularly mollusks and crustaceans

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• Root vegetables: Like potatoes and carrots.
• Organ meats: Liver and kidney from animals exposed to cadmium.
• Chocolate and cocoa products: Can contain higher cadmium levels due to soil contamination

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Toxicity and Mechanisms

• Oxidative stress: Cadmium induces the production of reactive oxygen species, leading to cellular damage and apoptosis

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• Disruption of calcium signaling: Interferes with cellular calcium homeostasis
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• Epigenetic changes: Causes DNA methylation and histone modifications, affecting gene expression
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• Disruption of cellular signaling pathways: Affects pathways such as MAPK, NF-κB, and p53, contributing to pathological conditions and cancer
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• Immune system effects: Reduces immune cell function and alters gut microbiome composition

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Accumulation in the Body

• Cadmium accumulates in the body, especially in the kidneys and liver, but also in the lungs, gut, and bones

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• Biological half-life: Estimated at 10–35 years, making long-term accumulation and toxicity a significant concern

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Diseases and Health Effects

• Kidney damage: Nephrotoxicity is the most well-known effect, leading to renal dysfunction and failure

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• Liver damage: Causes fibrosis, steatosis, and hepatotoxicity
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• Bone disease: Linked to osteoporosis and reduced bone mineral density
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• Cancer: Classified as a Group 1 carcinogen by the IARC, associated with lung, prostate, breast, pancreas, bladder, and nasopharynx cancers
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• Cardiovascular disease: Associated with increased risk of coronary heart disease, stroke, and peripheral artery disease
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• Neurological effects: Potential links to neurodegenerative diseases such as Alzheimer’s and Parkinson’s
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• Gastrointestinal effects: Causes inflammation and damage to the intestinal lining
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• Immune system effects: Suppresses immune function and alters gut microbiota

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Safe Levels

• Dietary intake: The European Food Safety Authority (EFSA) has set a tolerable weekly intake (TWI) of 2.5 μg/kg body weight for cadmium

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• Blood and urine: Regulatory agencies monitor cadmium levels in blood (recent exposure) and urine (long-term exposure) to assess health risks
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• Occupational exposure: Lower limits are set for workplace exposure to protect workers from chronic toxicity

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Summary Table

Cadmium is a cumulative toxin with significant long-term health risks, especially for those exposed to high levels through diet, smoking, or occupation

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