Antimony

Abstract

Antimony is a silvery-white brittle metalloid of medium hardness not known to be metabolized in mammals. It exists in four valence states: 0, -3, +3, and +5. Most absorbed antimony is excreted rapidly through the urine and feces. Elimination and the route of excretion depend on the type of antimony compound. Urinary excretion is higher for pentavalent than for trivalent antimony compounds, whereas gastrointestinal excretion is higher for trivalent than for pentavalent antimony. Some data on humans, as well as on animals, indicate that a small part of absorbed and retained antimony may have a long biological half-life, especially in the lung. After acute or chronic oral or parenteral exposure to antimony, the highest concentrations are found in the thyroid, adrenals, liver, and kidney.Industrial exposure may give rise to symptoms of irritation in the respiratory tract. Pneumoconiosis, occasionally in combination with obstructive lung changes, has been reported after long-term exposure in humans. Focal fibrosis of the lung has been seen in animal trials. Effects on the heart, even fatal, have been related to long-term industrial exposure to antimony trioxide. Secondary cardiovascular effects as a result of treatment of parasitic disease with antimony compounds have also been reported. In addition, cardiovascular effects have been observed in animal experiments. Rats exposed to antimony trioxide through inhalation for long periods of time showed a high frequency of lung tumors.