Beryllium
A toxic metal found in ores containing other elements that is used in making metal alloys for nuclear reactors and the aerospace industry.
Acute exposure to beryllium fumes can cause a severe, sometimes fatal pneumonitis (inflammation of the lungs).
Chronic overexposure to beryllium is more common and causes a diffuse inflammatory reaction in the lungs resulting in granulomas and fibrosis of the lungs and, in time, increasing shortness of breath.
Beryllium poisoning is termed berylliosis