But the dangerous work done at other facilities offers ample reason for concern. For decades the federal government denied that workers were being harmed by nuclear weapons production. The recently released list of weapons-related sites is the latest step in that groundbreaking effort. Taken together with other government documents and interviews, the list opens a window on Chicago's historic role in the nuclear weapons industry and hints at the hazards that faced thousands of area workers, including machinists, welders, millwrights and engineers. Silverman said the main reason Chicago had so many firms doing weapons work was the proximity of the U. of C., where researchers with the top-secret Manhattan Project led the nation's World War II effort to build an atomic bomb.
Beryllium is the hazard that researchers can most easily tie to weapons production.
More than 300 people have contracted beryllium disease at facilities doing weapons work, government and industry documents show. Lighter than aluminum but stiffer than steel, beryllium is used to amplify the chain reaction in a nuclear bomb. In bulk form the metal is relatively harmless. But when workers grind, sand or cut it and inhale the resulting dust, they can develop an incurable disease that slowly eats away at their lungs. A third die of the illness, a third become disabled and a third remain relatively healthy, doctors say.