Aluminum oxide, also known as alumina, is a chemical compound that contains aluminum ions and oxide anions. In the chemical formula Al2O3, the aluminum ion is a trivalent cation with a charge of +3. The oxide anions are of a smaller charge, usually -2, and are found in a close packed structure.
This ionic compound is used in many different industrial processes. It is also a component of antacid medicines. However, it can cause upper respiratory tract irritation.
When aluminum oxide is inhaled, it can irritate the mucous membranes of the nasal cavity and the eyes. If the exposure is chronic, it can lead to nonspecific chronic industrial bronchitis.
There is evidence that the small percentage of aluminium ions inhaled may be sequestered in the lungs. However, this is based on a study of the effects of a tagged gamma aluminum oxide.
One study exposed workers to finely divided aluminas, silica, and other substances. They developed dyspnea, pneumothorax, and other adverse effects. These included diffuse irregular lace-like granular shadows, fibrosis, and non-nodular fibrosis.
A study of female New Zealand rabbits exposed to a dust of aluminum oxide for five months revealed that the aluminum concentration in the brain was 2.5 times higher in the animals exposed to the dust than in control animals. Focal deposits of hyaline were also noted in the alveolar walls.
Exposure to corundum also caused respiratory difficulties. Workers in a corundum facility were exposed to fumes containing fine aluminum oxide. Although the workers did not experience pulmonary fibrosis, they did develop pneumothorax.