When investigating the biological effects of high-frequency RF, there are two quite different physical conditions you encounter, and you must interpret the results with a biological target accordingly:
1. When you are several wavelengths away from the transmitter (either the cell tower or phone), you are in the "far field", where you actually have radiation and a transmission of power.
2. When you are very close to the transmitting antenna (e.g., holding the phone up to your skull), you are in the "near field", where there is no actual radiation but energy is stored in the local field.
The relationship between these two limiting cases depends on the antenna. A conductive medium (like your brain) in the near field will dissipate power due to conduction and dielectric loss, heating the tissue. In regulations and measurements, this is called "SAR", measured in W/kg. It is used in regulations for cell phones and MRI systems, both of which are near-field conditions. There are hypothetical effects of the E-field (either radiated or near field) itself on biological systems (other than heat), but I'm not familiar with the current state of this research. There are well-documented accidental doses from high-power military radar exposure (far field), including cataracts (again, probably thermal).
Anyway, when investigating possible harm, the situation is different for a relatively high-power antenna on a pole high above a schoolyard, and a relatively low-power antenna and other electronics very close to your head.
A muckraking article in the Chicago Tribune a couple of years ago took several current-model cell phones to an independent lab, who measured the SAR and found that several were over the US legal limit.