PDF Version: http://mcs-america.org/August2009pg12345.pdf
Online Version: http://mcs-america.org/mcsanewsaugust2009.htm#_The_Facts_About
"Unmodulated radio waves are relatively safe. It has been known since the work of Suzanne Bawin and her co-workers in the mid 1970s that pure low power radio waves, of strengths similar to those used by cell phones, are relatively harmless. Pretty much the only damage that can be done by an unmodulated signal is due to the heating effect of the radiation as it passes through the body, and the ICNIRP safety guidelines adopted by many governments are more than adequate to protect you against that.
Modulated radio waves are not safe. Bawin et al. also showed that the situation changes drastically when the signal is "amplitude modulated" so that its strength rises and falls in time with a lower frequency. In particular, they found that signals that were far too weak to generate significant heat, could now drive structurally important calcium from the surfaces of brain cells. Other work showed that pulses with very sharp rise and fall times were even more effective. The loss of this calcium weakens the membrane and makes it more likely to leak and gives unwanted biological effects."