Mercury poisoning

Question 1

Forms entering body?

Answer 1

• Elemental mercury
• Mercury salts
• Organic Hg (methyl-Hg)

Question 2

Sources of intoxication?

Answer 2

Elemental mercury:

• Manufacture of electrical equiments
• Paint products
• Dental amalgam

Mercury salts:

• Disinfectants (bactericidal)

Question 3

Route of absorption?

Answer 3

• Elemental mercury* - respiratory tract
• Mercury salts* - GIT and skin
• Organic Hg* - GIT (methyl-Hg eliminated in bile and reabsorbed), skin and respiratory tracts

Question 4

Distribution?

Answer 4

• Soft tissues
• Kidney (mainly)
• Brain (methyl-Hg)

Question 5

Elimination?

Answer 5

Kidney

Question 6

Acute clinical effects and its treatment?

Answer 6

Acute (hydragyrism) clinical features:

• Elemental mercury - Pulmonary edema
• Mercury salts - Corrosive hemorrhagic gastroenteritis ==> hypovolemic shock
• Acute tubular necrosis
• Oliguric kidney failure
• Anuria

Therapy:

• Supportive care
• Dithiol chelators

Question 7

Chronic clinical features and its treatment?

Answer 7

Chronic symptoms:

• Tremor (choreiform movements of limbs)
• Neuropsychiatric distubrances
  
  • Memory loss, fatigue, insomnia, change in mood (depression and anger may alternate)
• Neuropathy
• Anemia
• Gingivostomatitis
• Loosening of skin
• Kidney damage
• Acrodynia (children): painful erythema of the extremities

Treatment:

• Chelators ?
• Dimercaprol redistributes mercury to CNS

Question 8

Clinical features of methyl-mercury poisoning?

(Minamata disease)

Answer 8

• CNS symptoms:
  
  • Paresthesia
  • Ataxia
  • Visual and hearing impairement
  • Tremor
  • Spasticity
  • Coma, death
• Prenatal exposure ==> mental retardation!