Geez, I hate thinking about things like this, AKA facing the truth.
In my humble opinion, pretty much *everything* modern, everything that is "hi tech" & takes us away from hard work farming organically under the glorious sun every day (as most humans did to some extent or another through out history), is bad for us. It's just up to each of us to decide how much of a toxic load we're willing to carry. And it really sucks IMO.
Computers do release electromagnetic rays. Some people do claim that they are ruining the humans that sit in front of them. Along with those folks that use microwave ovens, sleep with an electric alarm clock next to their beds, use cell phones, or, I even read a site talking about how unhealthy those little light up toddler shoes are! You can Google "electromagnetic rays from computer are harmful" as a start if you're willing to. This short article
has a little info.
I personally don't use microwave ovens or cell phones because I want to protect myself from cancers the best I can.... but I still live within a mile of major power lines, and sit in front of this computer.... and dye my hair.
We all have to decide how much we're willing to do to find a comfortable balance I guess.
It's all just really sucky if you ask me.
I think we really are surrounded by toxins.
ETA: I'm so computer clueless that I didn't even know if we have wifi in our house or not. Just now when I was telling DH about some of the scary things I was just reading about, related to having wifi in your house, he said "I know, that's why I ran that cord all over the house & plugged all the computers in right after we moved in". lol That was 2.5 yrs ago. Shows how much I pay attention. But I'm glad my husband's on top of these things.
He also has been trying to convince me to get a regular old cord telephone in our house instead of cordless phones for the same reason. But so far I haven't been willing to give in.