In 2015 one case got on the upper atmosphere that radiations from smart watches was observed Scientists aren’t willing to say that no, beyond any shadow of a doubt, cell phones increase the likelihood of cancer(because such a statement, barring some radical discovery followed by several remarkably longterm and well-done follow-up studies, would be a dumb one for a scientist to make) so we should probably all be concerned about cell phones, and by extension the new smart devices like fitness trackers and smartwatches. I mean, we all use them, but at what cost, by God.