More research has been published supporting the belief that electromagnetic fields can have a negative impact on the brain. Because research on human fetuses is unethical--as it should be--these researchers used Wistar rats. Their findings, published in the March 6, 2014 issue of Toxicology and Individual Health, found that rats exposed prenatally to the type of wireless radiation commonly found in cell phones (and wireless routers and security systems) showed deficits in both the ability to acquire new skills and the ability to remember what was learned.
The researchers also used EEGs to measure brain function and found clear differences between groups exposed to the radiation and those not exposed. The only good news is that examination of the brains themselves showed that cell structure was the same.
This is in contrast to another study which showed that the hippocampus--an important region for learning and memory--was smaller and had a reduced number of cells. Here is the abstract for that study:
The effects of electromagnetic fields (EMFs) emitted by mobile phones on humans hold special interest due to their use in close proximity to the brain. The current study investigated the number of pyramidal cells in the cornu ammonis (CA) of the 16-week-old female rat hippocampus following postnatal exposure to a 900 megahertz (MHz) EMF. In this study were three groups of 6 rats: control (Cont), sham exposed (Sham), and EMF exposed (EMF). EMF group rats were exposed to 900 MHz EMF (1 h/day for 28 days) in an exposure tube. Sham group was placed in the exposure tube but not exposed to EMF (1 h/day for 28 days). Cont group was not placed into the exposure tube nor were they exposed to EMF during the study period. In EMF group rats, the specific energy absorption rate (SAR) varied between 0.016 (whole body) and 2 W/kg (locally in the head). All of the rats were sacrificed at the end of the experiment and the number of pyramidal cells in the CA was estimated using the optical fractionator technique. Histopathological evaluations were made on sections of the CA region of the hippocampus. Results showed that postnatal EMF exposure caused a significant decrease of the pyramidal cell number in the CA of the EMF group (P<0.05). Additionally, cell loss can be seen in the CA region of EMF group even at qualitative observation. These results may encourage researchers to evaluate the chronic effects of 900 MHz EMF on teenagers' brains.
A caveat: the sample size in both experiments was small: 8 rats per group in the first experiment and 6 rats per group in the second. These experiments should be replicated using a larger population of animals.
The take-home message: when your elementary school age child begs you for a cell phone, you may want to talk to him about this research.