Los Alamos National Laboratory (LANL) in New Mexico is warning thousands of employees and visitors of a possible exposure to hazardous beryllium dust.

Letters were sent on Wednesday to nearly 2,000 people notifying them that, between 2001 and the end of 2008, they may have been exposed to a fine beryllium powder found in a room used for storing old and surplus materials. The powder can cause the uncurable Chronic Beryllium Disease, a progressive, debilitating and occasionally deadly lung disease.

“Chronic Beryllium Disease is very rare, and a very small percentage of the population is susceptible,” said LANL spokesman Kevin Roark. “The vast majority of the people that were in there, were there for very short periods of time. We’re not really expecting anyone to have an exposure.”

Only about 2 percent of the general population has a genetic susceptibility to the disease, and, of those, only a small fraction end up being sickened, depending on the duration and severity of exposure to the dust, says Roark. More information about beryllium exposures can be found here.

The notification letters were sent to 240 people who regularly worked in the room, as well as 1,650 visitors to the room — which includes about 1,000 current and former LANL employees as well as 650 non-lab visitors.

The last time the room had been screened for beryllium was in 2001, so the lab went back to logbooks to find everyone who had entered it. Beryllium, a strong and light metal, is used in things such as golf clubs, bicycles — and nuclear weapons. It is only dangerous when inhaled as a dust.

The threshold the lab has set for beryllium contamination is 0.2 micrograms per 100 square centimetres. Checks in November and December found levels as high as several hundred micrograms per 100 square centimeters, Roark said.

He encouraged those notified to contact the lab, and to take a free genetic test to see if they are susceptible to the disease. The storage facility is being decontaminated and is set to re-open in February.