Carpenter is the director of the Institute of Health and Environment at the University of Albany.
"Because the skull is so thin, and the head is relatively small, the radiation penetrates almost through the head. In the adult, it only penetrates a smaller distance, so the exposure for children is greater than that of an adult," said Dr. Carpenter.
Other scientists disagree, saying the low energy produced by cell phones cannot penetrate bone. Some point out, that while the use of cell phones has exploded, the incidents of brain tumors is down.