Scientists with EMFscientist.org say effects include increased cancer risk, cellular stress, increase in harmful free radicals, genetic damages, structural and functional changes of the reproductive system, learning and memory deficits, neurological disorders, and negative impacts on general well-being in humans. According to the National Cancer Institute (NCI), cell phones emit radio frequency waves, a form of non-ionizing radiation. Some compare it to holding a microwave to your head. NCI says tissue near where the phone is held can absorb that energy.