According to The New York Times and reputable researchers like Dr. Henry Lai of the University of Washington, indicates that about 70% of the non financed wireless-industry studies show that the everyday radiation has a bad biological impact. The biological effects can be ordered in 3 different categories: the cell growth, the DNA-replication and the neurological functions.
The impact on the cell growth went from a set delay of the cell growth and cell damage, to a disturbance of the cell adhesion (Aldinucci et al. 2003, Buemi et al. 2001, Pacini et al. 1999, Raylman et al. 1997, Linder-Aronson & Lindskog 1995).
On a genetic level deviations in the gene expression (Hirose et al. 2003, Hirai et al. 2002) and in the fetal development have mainly been established at the level of the cardiovascular system. Until today most studies have been done in a controlled laboratorium. It’s hard to say how this manifests on a scale of the population. It can take quite some years until the side-effects have been discovered (in addition, exposure to radiation in order of magnitude more than 15 years ago).
The fear is that small but overall scattered changes in the cellular and genetic processes in the early childhood will have an effect on the development, especially for children. The brain of children is constantly developing and their tissue absorbs relatively much radiation compared to adults.