This kind of result is indicative of cause and effect. So they do expose our heads to measurable RF radiation. Hence, portable non-cell phones are low risk, but not risk free. Some people report a 'fuzzy head' after a long call on a portable phone. Cell phone users describe dose-response symptoms of dizziness, loss of memory and concentration and headaches.
Some people also report nausea.
This probably is caused by differential heating of fluid in the middle ear affecting the balance mechanism. Your report has confirmed to me what I have already been coming to the conclusion about recently. However, I'm absolutely sure it's true. My brother tells me that his eye starts twitching uncontrollably when he uses his. On longer conversations, I find myself needing to shift frequently from ear to ear to get relief.