They Stood Sentry over America's Nuclear Missile Arsenal. Many Worry It Gave Them Cancer.

Danny Sebeck was shaving on an August day in 2022, when he spotted a lump on his neck he hadn't noticed before. It was probably nothing, he thought.

Later that month, he was talking with a close friend who said he had noticed a similar bump, too. The two had served together at Malmstrom Air Force Base, Montana, as missileers -- a high-stress job in which young officers are stationed below ground in launch control centers to keep careful watch over and, if called upon, fire America's nuclear intercontinental ballistic missiles.

While Sebeck was feeling OK, his friend was experiencing fatigue, night sweats and swollen lymph nodes and decided to go to his doctor. Shortly after, his friend learned he had non-Hodgkin lymphoma, an aggressive form of cancer that can be fatal to nearly one-third of those who receive a diagnosis, according to the American Cancer Society.