Mobile Phone Affects Cerebral Blood Flow in Humans

Abstract

Mobile phones create a radio-frequency electromagnetic field (EMF) around them when in use, the effects of which on brain physiology in humans are not well known. We studied the effects of a commercial mobile phone on regional cerebral blood flow (rCBF) in healthy humans using positron emission tomography (PET) imaging. Positron emission tomography data was acquired using a double-blind, counterbalanced study design with 12 male subjects performing a computer-controlled verbal working memory task (letter 1-back). Explorative and objective voxel-based statistical analysis revealed that a mobile phone in operation induces a local decrease in rCBF beneath the antenna in the inferior temporal cortex and an increase more distantly in the prefrontal cortex. Our results provide the first evidence, suggesting that the EMF emitted by a commercial mobile phone affects rCBF in humans. These results are consistent with the postulation that EMF induces changes in neuronal activity.

Acute Mobile Phones Exposure Affects Frontal Cortex Hemodynamics as Evidenced by Functional Near-Infrared Spectroscopy

“…fNIRS during exposure to mobile phones G Curcio et al These findings support the notion that an acute 40-mins exposure to a GSM signal emitted by a commercially available MP affects the frontal hemodynamics, as indexed by fNIRS. This result extends the PET data showing a metabolic increase over the anterior regions (Aalto et al, 2006;Huber et al, 2002Huber et al, , 2005, and provides a physiologic substratum to the attentional improvements observed under GSM irradiation (e.g., Koivisto et al, 2000;Curcio et al, 2004).…”

“…Conversely, if changes in [HHb] concentration mainly reflect variations in oxygen supply, it will be positively correlated with local activation. According to this second hypothesis, the observed increase in [HHb] as a function of MP exposure may be interpreted as a local activation, coherent with the PET studies (Aalto et al, 2006;Huber et al, 2002Huber et al, , 2005.…”

“…However, no change in rCBF as a function of the exposure to RF GSM-like signals has been found during the performance on a visual memory task (Haarala et al, 2003), with the exception of a rCBF decrease in the bilateral auditory cortex, possibly because of the noise coming from the working battery. This acoustic confounding effect was ruled out in a methodologically improved protocol (Aalto et al, 2006), in which a decrease in rCBF during the active exposure condition in the fusiform gyrus (directly under the antenna) and a bilateral increase in the medial and superior frontal gyri have been observed. Taken together, these data indicate that exposing the brain to a MP may induce an increase in rCBF in the prefrontal areas.…”

“…To enhance the validity of this study, the protocol will mimic a normal MP daily exposure (a 40-min exposure). Thus, given the well-known responsivity of the frontal-prefrontal cortex to the RF irradiation (Huber et al, 2002;Aalto et al, 2006) and considering that the MP exposure can improve frontal functioning, as suggested by behavioral data (e.g., Koivisto et al, 2000;Curcio et al, 2004), we hypothesized that the MP exposure will induce an increased activity over the frontal areas as measured by fNIRS.…”

GSM Mobile Phone Radiation Suppresses Brain Glucose Metabolism

“…In addition, a 10-minute interval between phone exposure and subsequent scanning makes the relationship between exposure and CBF responses questionable. In contrast, Aalto et al (2006) Here, we measured relative cerebral metabolic rate of glucose (CMRglu) to trace brain activation (Chang et al, 1987). Cerebral metabolic rate of glucose and CBF are closely coupled (Fox et al, 1988) but represent different physiological processes: CMRglu is a more direct marker of neural activity than CBF.…”