Prolonged exposure to high levels of cobalt or cobalt-containing substances can have adverse health effects, particularly on the respiratory system. These may include asthma-like symptoms, shortness of breath, coughing, and wheezing. In rare cases, cobalt exposure can also lead to a condition called “cobalt lung” or hard metal lung disease. It is important to handle cobalt and its compounds with caution and follow safety guidelines to minimize the risks.