Gallium, Indium, and Thallium

Abstract

Abstract The chemical elements gallium, indium, and thallium belong to group IIIA in the periodic table. Thallium developed a well‐deserved reputation for its toxic properties and was recognized as a potent accidental, occupational, and environmental poison, with many homicide and suicide reports. Although gallium and indium are not as toxic as thallium, their production represents an important source of exposure, due to their increasing applications in semiconductor electronic devices. Gallium compounds particularly produce kidney and pulmonary toxicity, with depression of the immune system. Indium compounds mainly induce nephrotoxicity, and developmental toxicity, as well as effects on the pulmonary system. In contrast, thallium compounds act as general poisons. Some compounds are also capable of altering various cellular defense mechanisms involved in carcinogenesis. However, many aspects of the toxicity of these individual compounds in the environment and human beings, including toxicokinetics, mechanisms of action, carcinogenic and teratogenic potential, and the best treatments for acute poisoning, remain to be elucidated.