Lead and Other Heavy Metal Toxins

Lead and Other Heavy Metal Toxins

Shane M. Meehan, MBBCh

Acute tubular injury with prominent eosinophilic nuclear inclusions image is evident in this example of acute lead nephropathy. There is mild interstitial edema and inflammatory exudates.

Acute lead nephropathy has nuclear inclusions composed of central, electron-dense spicules image and a halo of less electron-dense material image by electron microscopy. (Courtesy A. Cohen, MD.)



  • Group of disorders characterized by renal dysfunction due to toxic effects of lead and other metals


Toxic Renal Injury

  • Principal toxic metals encountered include lead (Pb), mercury (Hg), gold (Au), cadmium (Cd), copper (Cu), chromium (Cr), bismuth (Bi), antimony (Sb), arsenic (As), uranium (U), platinum (Pt), iron (Fe), and lithium (Li)

  • Exposure to toxic metals may be environmental, occupational, iatrogenic, or secondary to metabolic and hematologic disease states

  • Routes of entry include ingestion, inhalation, and absorption through skin

    • Environmental exposure

      • Ingestion: Contamination of water supplies in lead pipes or lead soldered joints, moonshine stills, lead paint, contaminated foods

      • Inhalation: Lead, mercury, and cadmium vapors, fumes, or dust

      • Application of mercury-containing skin lightening products

      • Mercuric chloride and colloidal bismuth ingestion in suicide

    • Occupational exposure

      • Paint manufacture and spraying, plumbing, welding, smelting, mining, pesticides, thermometer manufacturing, and others

    • Iatrogenic exposure

      • Gold therapy in rheumatoid arthritis

      • Colloidal bismuth in treatment of peptic ulcer and syphilis

      • Copper intrauterine contraceptive devices

      • Lithium in bipolar disorders

      • Platinum in cancer chemotherapy

      • Iron for deficiency states

    • Metabolic and hematologic diseases

      • Hemochromatosis

      • Wilson disease

      • Hemolysis

  • Metals may be absorbed through gastrointestinal tract, lungs, or skin, entering bloodstream

  • Circulating metals are filtered by glomeruli, often secreted by tubules and excreted in urine

  • Renal injury is by 2 principal mechanisms

    • Direct tubular toxicity causes tubular injury

      • High-dose exposure leads to acute nephropathy

      • Low-dose prolonged exposure leads to chronic nephropathy

    • Glomerular immune complex deposition results in membranous glomerulopathy

      • Associated with gold and mercury toxicity

      • Neither metal is detected in immune deposits



Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Lead and Other Heavy Metal Toxins

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