I should point out a couple of factors that you missed.. First, 3E+8m/s is the speed of light/radio waves while traveling in a vacuum, traveling through flesh is somewhat slower, velocity factor 0.6 to 0.7, (shorter actual wavelength).. Second item, peak exposure across tissue is 1/2 wave length(peak to peak), thus peak exposure is down to 40mm range. which is way larger than an average 2 gram rat brain(reduced occurrence), no so for humans.
As we bring the cell phone in closer to our bodies, the received S/N ratio drops, (our body blocks the received signal), which in turn causes the phone to ramp up it's transmit power.
As for physical effects, I 've got a pair of slowly healing rf burns on my right inner thigh(10 years+). They are located where the two ends of my old moto cell phone antenna used to sit in my right pants pocket. That's more than enough evidence for me..
Procedure to reduce RF exposure, distance is your friend, keep your cell phone as far away from your body as possible. My cell phone resides in a outer pocked of a backpack, while I'm driving/biking/etc. At home it's a minimum of several meters away being charged up, bluetooth'd to my low power DECT cordless phones. P.S. The higher cell phone frequencies are some what more dangerous, and they have been in widespread use for the last 10 to 15 years.