Hard metal lung disease

The inhalation of hard metal may produce various respiratory manifestations including upper respiratory tract irritation, asthma, hypersensitivity pneumonia (HP), and a particular form of interstitial lung disease. Co is the main cause of the adverse health outcomes in hard metal workers. A particular form of interstitial lung disease, called hard metal lung disease (HMLD) includes giant cell interstitial pneumonia (GIP) and pulmonary fibrosis. Clinical and radiologic features of GIP resemble those of HP. In patients with HMLD, pulmonary fibrosis showing usual interstitial pneumonia (UIP) pattern is found. It is unclear that GIP progresses to severe fibrosis showing UIP pattern if the exposure to hard metal is not stopped. Follow-up CT scans suggest that GIP dose not progress to fibrosis showing UIP pattern. GIP and hard metal induced pulmonary fibrosis may be two different representations resulting from exposure to hard metal. Under current diagnostic criteria, both GIP and pulmonary fibrosis with UIP pattern are included.

Cobalt exposure can occur inhalation, ingestion, and dermal routes. There is knowledge regarding the importance of cobalt ions skin absorption in relation to absorption via the respiratory tract in cobalt exposure. Co ions skin absorption can be considered as the reason that cases of hard metal workers’ asthma and HMLD occur more often at the wet area than at the dry area.