Chromium toxicity

Background

  • Blue white metal
  • Essential in glucose and fat metabolism
  • The predominant forms are trivalent (Cr3+) and hexavalent (Cr6+)
  • Cr6+ is a carcinogen
  • Uses
    • Chrome platting
    • Component of making stainless steel
    • Used to make cement
    • Welding
    • Joint arthroplasty
    • Coronary artery stents
    • Tanned leather products

Toxicokinetics

Form Toxicity Absorption Distribution Elimination
Cr3+
  • Rarely develops toxicity
  • Limited oral absorption with 98% recovered in feces
  • Urinary excretion
Cr6+
  • Main cause of toxicity
  • Oxidative agent producing oxidative DNA damage
  • Modestly absorbed
    • 10% orally
    • 50-85% inhalational
  • 50% total body burden is localized to the kidney and liver
    • With additional stores in bone marrow, lymph nodes, spleen, and testes
  • Cr6+ is rapidly converted to Cr3+ in the blood

Clinical Features

Acute

Chronic

  • Most are occupational inhalation exposures
  • Chrome holes
    • Nasal septal perforation
    • Skin ulcerations
  • Chronic cough
  • Dyspnea and bronchospasm
  • Anaphylactoid-like reactions
  • Pneumoconicosis
  • Increase risk of lung cancer
    • Small cell lung cancer, however all types are associated with Cr6+ exposure
  • Contact dermatitis and Type IV hypersensitivity reaction

Differential Diagnosis

Heavy metal toxicity

Evaluation

  • BMP
  • LFTs
  • CBC
  • CPK
  • EKG
  • If toxicity present add coagulation factors

Chromium levels

Baseline levels have varied over the past 50 years by 5000-fold, additionally it is difficult to establish standard reference range, use caution when interpreting these levels; phlebotomy needles and blood containers for storage can contain chromium

  • Whole blood: 20-30 μg/L (380-580 nmol/L)
  • Serum: 0.05-2.86 μg/L (1-56 nmol/L)
  • Urine: < 1μg/g creatinine (<19.2 nmol/g creatinine)
    • Can reflect acute absorption of chromium over the past 1-2 days, however wide variation in metabolism and total body burden

Management

  • Decontamination
    • Activated charcoal not indicated
    • Consider NG lavage if Cr6+ ingestion and presenting within 1-2 hours without signs of vomiting
    • Consider oral N-acetylcysteine
      • Shown to increases renal elimination of chromium in rats
  • Supportive care
  • Chelation
    • Not effective in reducing chromium levels
  • Dialysis
    • Not effective in those with normal renal function
    • Consider in those on chronic dialysis

Disposition

  • Acute toxicity likely requires intensive care unit
  • Consult Toxicology or poison control

References

Bird, S. Chromium. In: Goldfrank's Toxicologic Emergencies. 9th Ed. New York: McGraw-Hill; 2011: 1243-1247