Effects of Electromagnetic Fields on the Blood Brain Barrier

摘要

This report results from a contract tasking Lund University Hospital to investigate the effects of electromagnetic fields (EMF) in the 91 5-2450 MHz range on the permeability of the blood brain barrier (BBB) in rats. Male and female Fischer rats were exposed to continuous wave or pulse-modulated EMF, with different pulse powers and times up to 960 minutes. Albumin and fibrinogen were demonstrated immunohistochemically in perfused brains and classified as normal vs. pathological leakage. Leakage in exposed rats was significantly increased vs. controls. Researchers found no pronounced difference between various modulation frequencies, though continuous radiation seemed more effective in opening the BBB. There also appeared to be a biphasic closing of the opened BBB, including a fast component with a half-time of about 20 min and a more prolonged slow component. Studies related to global system for mobile communication (GSM) microwave exposures showed increased BBB permeability with GSM-900, 217-Hz modulation as well as with GSM-1800. Although results indicated that microwave exposure produced an effect on the BBB in rats, researchers noted that their method for detecting albumin leakage across the BBB was extremely sensitive and felt that small amounts of leakage detected may be harmless.