Cobalt

General information

Cobalt is a metallic element (symbol Co; atomic no. 27). It is an important constituent of the cobalamins (vitamin B ₁₂ ) and is found as arsenates and arsenides in naturally occurring minerals such as erythrite, skutterudite, and smaltite.

Cobalt has been used in the treatment of anemia, because of its erythropoietic action. However, it is toxic to many organs, and its medicinal benefits have repeatedly been questioned. In most countries the use of cobalt in anemia has been abandoned, although it is possible that in very rare cases there may be a need for it. If it is still to be used at all, the administration of cobalt ought to be entrusted to an experienced clinical hematologist.

Adverse effects are related to wear and loss of integrity of these implants in the course of time and are often related to the mechanics. On the other hand, specific ions may leak from the implants and concentrations may be increased in the surrounding tissue [ , ].

Occupational exposure is mainly due to cobalt powders. Its main other uses are in metal alloys and medical devices (for example aneurysm clips) [ ].

The toxicity of cobalt has been reviewed [ , ].

One tragic case in 1989 concerned a 13-month-old baby treated with a commercial iron–cobalt formulation that was still on sale, resulting in hypothyroidism, cardiomyopathy, polycythemia, and hypertrichosis [ ].