heavy metals

• Management of Specific Poisons Module 13: Heavy Metals

  • Antimony and Stibine
  • Barium
  • Cadmium
  • Copper
• Poisons


  • Zootoxins
  • Phytotoxins
  • Synthetic toxins
  • Minerals
• Antimony and Stibine


  • Widely used as a hardening agent in softmetal alloys
  • Used in compounding rubber, in flame proofing compounds, and as a coloring agent in dyes, varnishes, paints and glazes
  • Exposure to antimony dusts and fumes may also occur during mining and refining of ores and from the discharge of firearms
• Antimony


  Used in core bullet
• Stibine


  Colorless gas with the odor of rotten eggs that is produced as a by-product when antimonycontaining ores or furnace slag is treated with acid
• Stibine production


  Solid antimony reacts with acids or heat
• Mechanism of toxicity for antimony and stibine

  May be similar to arsenic and arsine - SAME TOXIC EFFECT CAUSING: PROTOPLAMIC POISON- material that can damage living cells
• How antimony compounds act

  Binding to sulfhydryl groups and inactivating key enzymes
• How stibine acts


  Like arsine, may cause hemolysis. It is also an irritant gas
• Effects of antimony and sulfhydryl group

  Malfunctioning of: Respiration, cell enzymes, mitosis
• Lethal oral dose of antimony in mice is 100 mg/kg
• Recommended workplace limit (ACGIH TLVTWA) for antimony is 0.5 mg/m3 as an 8-hour time-weighted average
• Recommended workplace limit (ACGIH TLVTWA) for stibine is 0.1 ppm as an 8-hour timeweighted average
• The air level considered immediately dangerous to life or health (IDLH) for stibine is 40 ppm
• Acute ingestion of antimony causes

  • Nausea
  • Vomiting
  • Diarrhea (often bloody)
  • Hepatitis
  • Renal insufficiency
• Death is rare if the patient survives the initial gastroenteritis (inflammation of the lining of the intestine)
• Acute stibine inhalation causes

  • Acute hemolysis resulting in anemia, jaundice hemoglobinuria and renal failure
• Chronic exposure to antimony dusts and fumes may result in

  • Headache
  • Anorexia
  • Pneumoconiosis (occupational lung disease)
  • Peptic ulcers
  • Dermatitis (antimony spots)
  • Sudden death resulting from a direct cardiotoxic effect (myocardial infarction)
• Antimony trioxide Sb2O3 is cancerous
• Normal serum and urine antimony levels are below 10 µg/L
• Urinary antimony is increased after firearm discharge exposure
• Other useful laboratory studies

  • CBC, plasma free hemoglobin, electrolytes, BUN, creatinine, urinalysis for free hemoglobin, liver transaminases, bilirubin, prothrombin time (PT)
• Emergency and supportive measures for antimony poisoning

  Large-volume intravenous fluid resuscitation may be necessary for shock caused by gastroenteritis to inc. cardiac output and improve organ perfusion
• Emergency and supportive measures for stibine poisoning

  Blood transfusion may be necessary after massive hemolysis. Treat hemoglobinuria with fluids and bicarbonate as for rhabdomyolysis
• There is no specific antidote for antimony or stibine poisoning
• BAL (BRITISH ANTI-LEWISITE)


  A specific drug/antidote
• Decontamination for inhalation


  Remove from exposure and give supplemental oxygen if available. Protect rescuer from exposure
• Decontamination for ingestion of antimony salts (prehospital)


  Administer activated charcoal, if available and ipecacinduced emesis for initial treatment
• Decontamination for ingestion of antimony salts (hospital)

  Administer activated charcoal and perform gastric lavage. Do not use cathartics
• Enhanced elimination for stibine poisoning

  Exchange transfusion may be effective in treating massive hemolysis
• Barium


  • Poisonings are uncommon and usually result from accidental contamination of food sources, suicidal ingestion, or occupational inhalation exposure
  • Water-soluble barium salts (acetate, carbonate, chloride, hydroxide, nitrate, sulfide) are highly toxic
  • Insoluble barium sulfate is nontoxic because it is not absorbed, used as radiopaque medium
  • Soluble barium salts are found in depilatories, fireworks, and rodenticides and are used in the manufacture of glass and in dyeing textiles
  • Barium sulfide and polysulfide may also produce hydrogen sulfide toxicity
• Mechanism of toxicity for barium

  Systemic barium poisoning is characterized by profound hypokalemia, leading to respiratory and cardiac arrest. Barium ions have a direct action on muscle cell potassium permeability, which stimulates smooth, striated, and cardiac muscles, resulting in peristalsis, arterial hypertension, muscle twitching, and cardiac arrhythmias
• Inhalation of insoluble inorganic barium salts


  Can cause baritosis, a benign pneumoconiosis
• Pharmacokinetics of barium


  Barium is stored in bone and slowly excreted via the feces. Tissue distribution follows a 3- compartment model with half-lives of 3.6, 34 and 1033 days
• Minimum oral toxic dose of soluble barium salts is undetermined but may be as low as 200 mg
• Lethal doses of barium salts range between 1-30 g because absorption is influenced by gastric pH and foods high in sulfate
• Clinical presentation of barium poisoning

  • Hypokalemia
  • Skeletal muscle weakness progressing to flaccid paralysis of the limbs and respiratory muscles
  • Ventricular arrhythmias
  • Gastroenteritis with severe watery diarrhea
  • Mydriasis with impaired accommodation
  • CNS depression
• Diagnosis of barium poisoning is based on a history of exposure, accompanied by rapidly progressive hypokalemia and muscle weakness
• Blood barium levels are not routinely available
• Other useful laboratory studies for barium poisoning

  • Electrolytes (potassium), BUN, creatinine, arterial blood gases or pulse oximetry, ECG