A Quick Review of Mercury Poisoning
- Most human exposure results from fish consumption, dental amalgam, or occupational exposure.
- Approximately 80% of metallic mercury vapor outgassed from amalgams is absorbed through inhalation, compared with about 7 to 10% absorption of ingested metallic mercury, and about 1% absorption of metallic mercury through skin
Important Elemental Forms:
- Mercury vapor: Most toxic form. Transported to the brain, either dissolved in serum or adherent to red cell membranes.
- Metallic mercury: Passes easily through the blood brain barrier and through the placenta. Rapidly oxidized, although not so quickly as to prevent considerable uptake by the central nervous system
- Poisons cellular function by altering the tertiary and quaternary structure of proteins and by binding with sulfhydryl and selenohydryl groups.
- The chief target is the brain, but peripheral nerve function, renal function, immune function, endocrine and muscle function, and dermatitis.
- Low-level exposures: nonspecific symptoms like weakness, fatigue, anorexia, weight loss, and gastrointestinal disturbance
- Higher exposure levels:
- Mercurial tremor: fine muscle fasciculations punctuated every few minutes by coarse shaking.
- Erethism: severe behavior and personality changes, emotional excitability, loss of memory, insomnia, depression, fatigue
- Acute myocardial infarction, carotid atherosclerosis
- Blood and urine levels correlate fairly well to each other, but not to total body burden
- It has not been possible to set a level for mercury in blood or urine below which mercury related symptoms will not occur.
- DMPS: increases in urinary mercury output; evidence of decreased body burden
- Safer than British Anti-Lewisite and more potent than DMSA