ID Number		28
Study Type		In Vivo
Model		915 MHz (GSM, PW, CW) exposure to rats and analysis of blood brain barrier permeability.
Details		Fisher 344 (male + female) rats exposed to 900 & 1800 MHz in TEM cells either as CW or with modulation rates of 8, 16, 50, or 200 Hz for 2 hours at SARs between 0.016 and 5 W/kg (whole body average). Rats were anesthetized with chloral hydrate and brains examined immunohistochemically for albumin and fibrinogen leakage. Leakage of Evans Blue dye-labeled proteins was also performed in a related study (Persson et al., 1992, Ann NY Acad Sci; 649: 356-8). A moderate effect was found at all SAR below 2.5 W/kg, and increased with higher SAR between 2.5 and 5 W/kg. No clear difference between CW and PW, although the authors suggest that pulsed RF was somewhat more effective at opening the BBB than CW. No clear difference between the various modulations (8-200 Hz) was reported. In subsequent studies, Fisher 344 (male + female) rats were exposed to 900 MHz (GSM) in TEM cells connected to a GSM transmitter at SARs of 0.02, 0.2, and 2 W/kg. Rats were anesthetized with chloral hydrate and brains examined immunohistochemically for albumin leakage. An increase in albumin leakage and uptake in neurons at 6-8 weeks following exposure was observed at all RF exposure levels. In 2008, a subsequent study exposed rats (n = 80 exposed, 16 controls) to RF (GSM) for 2 hours at 0.12, 1.2, 12, or 120 mW/kg followed by 14 or 28 day recovery before sacrifice. The authors report significantly increased BBB leakage at all exposure levels after the 14 day recovery. After 28 days of recovery, there was no BBB leakage although the number of dark neurons. Both 14 and 28 day recovery showed significantly increased albumin uptake in neurons. There was some suggestion of an inverse dose response relationship for the parameters. A 2009 paper used the same rats and exposure system with 900 MHz (GSM) exposure for 2 hr at 0.0012, 0.01, 0.02, 0.12, and 1.2 W/kg. Animals were sacrificed 7 days after exposure and evaluated for blood brain barrier leakage. The authors report increased BBB permeability at a rate lower than that previously observed at day 0 or day 14 following exposure in prior studies. AUTHORS' ABSTRACT: Salford et al. 2011 (IEEE #6108): Our research group has studied the effects of electromagnetic fields (EMF) upon the mammalian brain (rats) since 1988. Our major field of interest during the period has been the effects upon the blood-brain barrier (BBB) of the rat. The mammalian brain is protected by the BBB from potentially harmful compounds circulating in the blood. In the normal brain, the passage of compounds over the BBB is highly restricted. Our studies have revealed that the EMF radiation of the kind emitted by mobile phones leads to increased permeability of the BBB both immediately after 2 hours of exposure, but also after 7 days, 14 days and 50 days, all at non-thermal exposure levels. Also, damaging effects from radiofrequency EMF upon neurons has been shown after 28 days and 50 days. Of what is known today, the human BBB is very similar to the rodent BBB. With our research into the field, and comparison to other studies of BBB permeability in connection to EMF exposure, it is our sincere belief, that it is more probable than unlikely, that non-thermal EMF from mobile phones and base stations do have effects upon the human brain.
Findings		Effects
Status		Completed With Publication
Principal Investigator		Lund University, Sweden
Funding Agency		NIWL, Sweden, Hans Merit Rausing
Country		SWEDEN
References		Nittby, H et al. Pathophysiol., (2009) 16:103-112 Eberhardt, JL et al. Electromagn Biol Med, (2008) 27:215-229 Nittby, H et al. Electromagn Biol Med., (2008) 27:103-126 Persson, BR et al. Wireless Network, (1997) 3:455-461 Salford, LG et al. Microscopy Research Technique, (1994) 27:535-542 Salford, LG et al. Bioelectrochem. & Bioenerg., (1993) 30:293-301 Persson, BR et al. Ann N Y Acad Sci, (1992) 649:356-358 Nittby, H et al. The Environmentalist., (2011) 31:140-148 Salford, LG et al. Eur. J. Oncol. Library., (2011) 5:333-355 Persson, BRR et al. Acta Scientiarum Lundensia., (2012) 2012-006:1-39
Comments		The study shows an unlikely pattern of BBB leakage effect throughout the brain that is not consistent with a direct effect of RF energy that would begin in the outer tissues where most of the RF energy at 900 & 1800 MHz would be deposited. Temperatures in the exposed animal brains were not well characterized, and at the higher exposure levels may have lead to local temperature increases. There is no clear dose response with SAR from 0.02-8.3 W/kg or consistent modulation dependent effect. Attempts to replicate these findings have so far been unsuccessful (Fritz 1997, Masuda Bioelectromagnetics 2000, 21:364-371). A more exact replication of this study performed by scientists at the U.S. Air Force Research Laboratory, Brooks Air Force Base, Texas in cooperation with the original investigators is currently ongoing (Merritt BEMS 2001) and should conclusively determine whether these original findings can be validated.