Signs and Symptoms of Cadmium Toxicity
Cadmium toxicity presents with a distinct pattern of symptoms affecting multiple organ systems, primarily targeting the kidneys, bones, lungs, and cardiovascular system, with manifestations varying based on acute versus chronic exposure.
Acute Cadmium Toxicity
Respiratory Symptoms
- Inhalation of cadmium oxide fumes can cause:
- Inhalation fever (metal fume fever)
- Chemical pneumonitis
- Shortness of breath
- Chest pain
- Cough
Gastrointestinal Symptoms
- Nausea and vomiting
- Abdominal pain
- Diarrhea
- Excessive salivation
Other Acute Symptoms
- Headache
- Dizziness
- Fever and chills
- Muscle aches
- Fatigue
Chronic Cadmium Toxicity
Renal Effects (Primary Target)
- Renal tubulopathy (earliest and most sensitive manifestation)
- Tubular proteinuria (increased urinary excretion of low molecular weight proteins like retinol binding protein)
- Progressive decline in glomerular filtration rate
- Potential development of renal Fanconi syndrome
- Eventual renal failure with prolonged exposure 1, 2
Skeletal Effects
- Osteomalacia (softening of bones)
- Diffuse osteoporosis
- Bone pain
- Increased risk of fractures
- Height loss 3
Cardiovascular Effects
- Hypertension
- Increased risk of cardiovascular disease 1
Neurological Effects
- Peripheral neuropathy
- Cognitive impairment
- Olfactory dysfunction
Other Chronic Effects
- Anemia
- Liver damage
- Reproductive system impairment
- Increased cancer risk (cadmium is classified as a human carcinogen by IARC) 3
Special Considerations
Environmental Exposure Signs
- Environmental cadmium exposure has been linked to higher blood pressure levels, particularly among women 4
- Cadmium toxicity can occur through various exposure routes:
- Respiratory system (13-19% absorption from air)
- Digestive system (10-44% absorption)
- Accumulation in tissues: 0.14-3.2 ppm in muscles, 1.8 ppm in bones, 0.0052 ppm in blood 1
Diagnostic Indicators
- Urinary cadmium concentration is the most relevant biological exposure index
- Early kidney effects can be detected at urinary cadmium levels between 0.5-3 μg/g creatinine 5
- Blood, hair, nail, and saliva samples can also be used to measure cadmium levels 6
Risk Factors and Vulnerable Populations
- Smokers (tobacco is a significant source of cadmium)
- Occupational exposure (battery manufacturing, metal plating, pigment production)
- Individuals with iron deficiency (increases cadmium absorption)
- People with pre-existing kidney disease, diabetes, or hypertension
- Children (more vulnerable due to higher absorption rates and developmental concerns) 4
Clinical Pitfalls to Avoid
- Tubular proteinuria is not detected by routine clinical dipstick testing for proteinuria
- Symptoms may be mistaken for other conditions due to their non-specific nature
- The long biological half-life (16-30 years) means symptoms may appear long after exposure has ceased 1
- Patients with cadmium toxicity require supportive care and possibly chelation therapy, though no specific chelating agent has been definitively established for human cadmium poisoning 3
Remember that cadmium toxicity should be considered in patients with unexplained renal dysfunction, especially when combined with bone abnormalities and a history of potential exposure through occupation, smoking, or contaminated food/water.