acute mercury toxicity


The patient has acute mercury toxicity. He works in a thermometer and manometer factory, and many of the medical manometers produced still contain mercury. He and several coworkers were exposed to mercury vapors. He has severe pneumonitis from the vapors. His urine mercury level was 272 μg/L (1,355.92 nmol/L), and his serum mercury level was 373 μg/L (1,859.41 nmol/L). A normal level is less than 5 μg/L (24.93 nmol/L).

Mercury is a toxic heavy metal that is widely dispersed in nature. Mercury is contained in many products, including batteries, measuring devices, electric switches and relays, lamps and light bulbs, dental amalgam, skin-lightening products, and pharmaceuticals. Mercury poisoning has a variety of clinical manifestations. Inhaled elemental mercury vapor, for example, is easily absorbed through mucous membranes and the lung and rapidly oxidized to other forms. Human toxicity varies with the form of mercury, the dose, and the rate of exposure. The target organ for inhaled mercury vapor is primarily the brain. Mercurous and mercuric salts chiefly damage the gut lining and kidney, and methylmercury is widely distributed throughout the body. Toxicity varies with dosage: large acute exposures to elemental mercury vapor induce severe pneumonitis, which in extreme cases can be fatal. Mercury levels can be measured in plasma, urine, feces, and hair samples. Urinary concentration is a good indicator of poisoning from elemental and inorganic mercury.

Treatment of mercury poisoning is supportive therapy along with dimercaprol (BAL), 2,3-dimercaptosuccinic acid and dimercaptopropanesulfoxid acid, which are used as chelating agents in severe mercury poisoning. After chelation, urine mercury levels should be checked to see whether there is an increase in urine levels. Several treatments may be required to bring down serum mercury levels. The urine and serum mercury levels of this patient through his treatment course are shown in Figure 5. He received both agents.

Corticosteroids would not treat pneumonitis from mercury vapors. Trimethoprim-sulfamethoxazole is the treatment for pneumonitis from Pneumocystis jirovecii pneumonia and not mercury poisoning. There is no evidence of P jirovecii pneumonia in this case.

Granulocyte-macrophage colony-stimulating factor is the treatment for silicon alveolar proteinosis, and there is no evidence of inhalation of silica in the occupational history.1

Footnotes

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