"the light spectrum" will show you that all EMF has energy levels by far lower than visible light, not to mention ultraviolet, x-ray and gamma ray. The last three which do cause problems to the body. What we do know is that any energy that doesn't ionize the cells isn't harmful. Visible light and below don't ionize the cells so they aren't harmful.

It's like having a giant rock wall and you are throwing stones at it. No matter how many stones you throw it's not going to do any damage to the wall. Ionizing radiation is like shooting cannons at that wall. It will cause damage to it. Luckily your body can repair itself, so as long as you aren't damaging it faster than it can repair itself then you are good (speaking very basic here).

Now, this is what the science says as it is known today. Could there be more that we don't understand? Sure, and I would be willing to admit my ignorance and accept the new findings when the need findings come. But, if visible light, which my body absorbs its energy for more than EMF, doesn't do damage to me then I don't see how EMF could.