I think smart phones are just generally bad for people, and not because of cancer.
I remember when people first started getting iPhones and Blackberries. They were really expensive, but seemed so advanced. I couldn't afford one, and I swore I'd never get one. I was paranoid about privacy issues: I didn't like the idea of a touchscreen ("but won't it turn on in my pocket?!"), and I hated how everyone seemed to be glued to their phones. I felt so superior hanging on to my "dumbphone" long after smartphones were standard.
Then I got one myself, and I'm now one of the annoying people that is glued to the phone. I think it's made my obsessions worse, because I always have the internet with me, or music, or a game, or a shopping list. I don't even have to interact with anyone.
This technology just helps us to stay in our own little worlds all day, even NTs. I think for me it's worse, because having ASD means I get "addicted" to things easily.