Of course its harmful. It affects us as well. Everyday, no matter how much sleep people get I hear them complain about being tired. Well, besides the garbage we eat, we are also tired because of all the artificial light.
Your phone alone does this. When you look at your phone at night the light tells your brain not to produce melatonin and that it's not yet time to sleep. Hence why it is even harder to fall asleep. Even when we do sleep it's not good, quality sleep. Your lights told your brain not to sleep, so you forced it. Then you sleep around artificial lights and active electronics.
Is it really a surprise you can never feel rested? I meet a ridiculous amount of people who "have" to sleep with their propaganda machine (t.v.) on. Of course it sadly doesn't matter because it isn't affecting people right now and in more obvious ways.
It's sad and bothersome that we have become so self centered and obsessed with materialism that we don't care what happens to our families once we are gone. Living unhealthy lives and leaving an unhealthy world for people we "care" about. But hey, screw it! I've got my cookies, sodas and America's Go "Talent"!