The important part is the wattage output of the antenna, which exponentially dissipates over distance (3D). We have lived in a soup of EM radiation for the past 100 years or so. Any more general long-term effects should become visible in the next years. Until now, it has been mostly harmless unless you get too close to a high-powered source for a very long time.
Discussion
I think the question is less about EMF sources but more modern High frequency stuff.
Evidence seems inconclusive, leaning not harmful at quick glance.
It’s really about whether it’s ionising radiation or not, being “too close” isn’t a real concern for phones and wifi.
Ionizing radiation is proven to be bad. I think most people discuss non-ionizing radiation in these topics. You can have non-ionizing radiation that enters the skin and blood with an amount of energy big enough to cause electronic excitation. That can be used for the good and the bad. See therapeutic photomedicine, for instance, where people beam the body with visible light at such a high level that it can temporarily cut neuron transmission and block pain.
Agree. My point is that frequency is not that important at the level we usually see in communications. The wattage of the wave is.