More than 1,000 former Chicago-area U.S. Department of Energy employees will be tested in an expansion of the federal government's health screening for employees who may have been exposed to beryllium dust or fumes in their work in the nuclear weapons program.

During the next two weeks, department officials said, former workers are to be contacted by mail. They include 461 from Argonne National Laboratory near Darien, 226 from Site B Metallurgical Laboratory that was part of the World War II-era Manhattan Engineer District program at the University of Chicago and 53 from Fermilab near Batavia.

In addition, 325 former employees of the Department of Energy and predecessor agencies, most of whom worked at Argonne, and 18 former workers from the department's Argonne site in Idaho will be contacted for testing.

The screening is an extension of a program begun about seven years ago, when the department started screening former employees at its Rocky Flats plant in Colorado, Oak Ridge facilities in Tennessee, and Hanford facility in Washington state. Other medical screenings were undertaken at the Los Alamos National Laboratory in New Mexico, Lawrence Livermore National Laboratory in California and more than 15 other sites.

The workers may have been exposed to harmful levels of beryllium, a metallic element used in nuclear reactors primarily for its ability to reflect neutrons. The affliction associated with exposure, chronic beryllium disease, brings about scarring in the lungs and restricts breathing. In some cases, it can be fatal.

Chronic beryllium disease is incurable but can be treated.

Most of the former employees probably were exposed to the metal dust of beryllium in machine shops, where the metal was drilled, ground and similarly manipulated, Department of Energy spokesman Brian Quirk said Monday.

The federal law to compensate those who contacted chronic beryllium disease was passed in 2000. The program calls for providing diagnosis, medical treatment and up $150,000 in compensation to each former employee or their heirs. The cost of the program remains uncertain, but estimates have ranged as high as $1 billion.

The employees who were exposed to the metal dust or fumes will be given blood tests starting July 31, Quirk said. Those who test positive will receive a second blood test and more extensive diagnostic examinations, Quirk said.

Current employees who work with beryllium are routinely screened for harmful effects. Former employees may call 877-447-9756 to receive more information.