Night Shift Linked to Cancer

Working the night shift might increase your risk of getting cancer, an international health agency says. That theory has been percolating for decades, but it will gain credence next month when the WHO declares night work a probable carcinogen, the AP reports. The designation, likely to be followed by the American Cancer Association, will put working at night into the company of UV radiation and anabolic steroids.

Studies have found an increase in breast cancer for women and prostate cancer for men among late-shift workers. Explanations are elusive, but most theories revolve around the disruption of the body's circadian rhythm and the mysterious healing properties of a good night's sleep. "The balance between light and dark is very important for your body," said one expert.  (More cancer stories.)