What is a major health condition associated with cobalt exposure?

Cobalt exposure is primarily associated with hard metal disease, which is a condition linked to the inhalation of cobalt-containing metal dust or fumes. This health issue is a form of pneumoconiosis, a lung disease caused by the long-term inhalation of certain dusts. Hard metal disease specifically arises in workers who handle hard metals, often containing cobalt as an essential component, leading to significant respiratory problems over time.

As cobalt is known for its use in various manufacturing processes, particularly in the production of carbide tools, exposure can result in lung inflammation and ultimately chronic respiratory conditions. Thus, individuals with sustained inhalation of cobalt dust may develop hard metal disease, which is detrimental to their lung function and overall health.

While other health conditions such as respiratory illnesses, cardiovascular diseases, and skin allergies may occur due to exposure to various toxic substances, hard metal disease is directly and specifically tied to cobalt exposure, making it the most appropriate answer to the question.