Lead

• Lead poisoning

  Also known as lead toxicity, a condition caused by increased concentrations of lead in the blood
• Lead

  • A heavy metal found in the environment, with no physiological function
  • Can cause both reversible and irreversible health effects depending on exposure
• No level of lead exposure is safe, children most commonly affected, adult males more frequently affected than females
• Acute lead poisoning

  Most commonly caused by occupational exposure
• Occupations with increased risk of lead exposure

  • Battery manufacturing and recycling
  • Lead mining and refining
  • Auto repair
  • Certain types of construction
• Chronic lead poisoning

  Most commonly affects children, from slow environmental exposure over time
• Sources of chronic lead exposure

  • Leaded paint in older homes
  • Leaded gasoline exhaust contaminating environments
  • Old toys with leaded paint
• How lead causes disease

  Affects heme synthesis, inhibits glutathione and superoxide dismutase, leading to increased reactive oxygen species and cell damage
• Effects of lead poisoning

  • Hematological
  • Gastrointestinal
  • Neurological
  • Renal
• Hematological effects

  Anemia, microcytic anemia with basophilic stippling, normal iron studies
• Gastrointestinal effects

  Abdominal pain, nausea, vomiting, diarrhea, constipation (in children)
• Neurological effects in children

  Irritability, aggression, decreased concentration, encephalopathy, developmental delay, language delay, school difficulties
• Neurological effects in adults

  Wrist drop (radial neuropathy)
• Serum lead levels associated with increased aggression and decreased IQ
• Lead lines

  Black/bluish lines on gums (Burton's lines) and long bone epiphyses
• Renal effects

  Fanconi's syndrome (phosphaturia, glucosuria, aminoaciduria), chronic lead nephropathy
• Cardiovascular effects

  Hypertension, increased risk of cardiovascular disease and stroke
• Reproductive effects

  Reduced libido, abnormal spermatogenesis, infertility in males, increased risk of miscarriage and stillbirth in females
• Mnemonic for clinical findings

  L - Lead lines, E - Encephalopathy and erythrocyte basophilic stippling, A - Abdominal pain/anemia, D - Drops (wrist/foot)
• Diagnosis of lead poisoning

  Measure whole blood lead level, free erythrocyte protoporphyrin levels, complete blood count with microcytic anemia and basophilic stippling, imaging for long bone lead lines and abdominal radio-opacities
• Treatment of lead poisoning

  Identify and remove lead source, monitor for health problems, chelation therapy with DMSA, EDTA or dimercaprol if lead level is high, gastric lavage and whole bowel irrigation, supplementation with vitamin C, iron, calcium and vitamin D