LOS ALAMOS, N.M. (AP) – Los Alamos National Laboratory says nearly 1,900 workers and visitors might have been exposed to beryllium, a substance that can cause lung disease.

The lab began notifying current or former employees and visitors after finding beryllium contamination in a storage area. They will be offered a chance to be tested, and decontamination of the area is under way.

Beryllium is a metal used in defense and aerospace industries that’s hazardous in finely powdered form. In rare cases, individuals who inhale the particles can develop a serious lung problem called chronic beryllium disease.

The contamination was discovered late last year. Officials say 240 employees who work in the affected area had the most potential exposure.