A huge study from Denmark offers the latest reassurance that cell phones don’t trigger cancer. Scientists tracked 420,000 Danish cell phone users, including 52,000 who had gabbed on the gadgets for 10 years or more, and some who started using them 21 years ago. They matched phone records to the famed Danish Cancer Registry that records every citizen who gets the disease–and reported Tuesday that cell-phone callers are no more likely than anyone else to suffer a range of cancer types.