Browse 8,700 peer-reviewed studies on electromagnetic field health effects from 4 research libraries.
Showing 2,764 studies in Brain & Nervous System
Borbely et al. · 1999
Researchers exposed healthy adults to cell phone radiation (900 MHz) during sleep using 15-minute cycles. The radiation reduced nighttime awakenings and changed brain wave patterns during deep sleep, showing that phone signals can directly affect brain function even at supposedly safe levels.
Unknown authors · 1998
University of Washington researchers exposed rats to 1 mT, 60 Hz magnetic fields (power line frequency) for one hour before each water maze training session. While the rats learned to find the platform normally, they swam slower and showed impaired spatial memory during testing, suggesting the magnetic field changed how their brains processed location information.
Unknown authors · 1998
Researchers exposed rats to 60 Hz magnetic fields (the same frequency as household power lines) for one hour before maze training sessions. While the rats could still learn to find a hidden platform, they swam slower and showed impaired spatial memory when tested later. This suggests power frequency magnetic fields may affect brain function and memory formation.
Unknown authors · 1998
Researchers exposed 256 male rats to 50 Hz magnetic fields at 5 microTesla for 22 hours daily over 32 weeks, covering about 70% of their lifespan. The study found no significant differences in blood chemistry, organ structure, or brain neurotransmitters between exposed and control animals. This suggests that prolonged exposure to power-line frequency magnetic fields at this intensity may not cause detectable biological changes in rats.
Unknown authors · 1998
Researchers exposed rats to 60 Hz magnetic fields (the same frequency as power lines) for one hour before water maze training sessions. While the rats could still learn to find a hidden platform, they swam slower and showed impaired spatial memory when tested later. This suggests power line frequency magnetic fields may affect brain function and memory formation.
Unknown authors · 1998
Danish researchers tracked over 21,000 utility workers for nearly 20 years and found they had twice the normal rate of death from ALS (Lou Gehrig's disease). The increased risk appeared linked to higher electromagnetic field exposure levels and repeated electrical shocks on the job.
Unknown authors · 1998
This 1998 analysis examined whether cellular telephone headaches are real phenomena by reviewing three decades of microwave research. The authors found compelling evidence that cell phone headaches are genuine, linking them to documented effects of low-intensity microwaves on the blood-brain barrier and brain chemistry systems. The study suggests these headaches may be early warning signs of more significant biological effects.
Wagner, P, Roschke, J, Mann, K, Hiller, W, Frank, C · 1998
German researchers monitored the sleep patterns of 24 healthy men using brain wave measurements while exposing them to cell phone-like radiofrequency signals (900 MHz GSM signals). The study found no statistically significant changes in sleep quality, REM sleep duration, or brain wave patterns during EMF exposure. The researchers noted their failure to replicate previous findings might indicate that EMF effects on sleep depend on the specific exposure dose.
Urban, P, Lukas, E, Roth, Z · 1998
Researchers exposed 20 healthy volunteers to electromagnetic fields from a Motorola mobile phone for 5 minutes and measured visual evoked potentials (electrical brain responses to visual stimuli) to see if phone radiation affected brain function. They found no changes in brain activity after the exposure. This small pilot study suggests short-term mobile phone use may not immediately disrupt this particular aspect of brain function.
Seaman RL, Belt ML, Doyle JM, Mathur SP · 1998
Researchers exposed mice to extremely high-intensity ultra-wideband electromagnetic pulses (99-105 kV/m) for up to 45 minutes and tested whether this affected their pain sensitivity and movement, including when combined with morphine. The study found no changes in pain response or activity levels in either normal mice or those given morphine. This suggests these particular electromagnetic pulses did not interfere with the nervous system pathways that control pain and movement.
Schonborn F, Burkhardt M, Kuster N · 1998
Researchers used computer simulations to compare how much cell phone radiation is absorbed by children's heads versus adults' heads at 900 MHz and 1,800 MHz frequencies. They found no significant differences in radiation absorption between children and adults, contradicting earlier studies that suggested children absorb more radiation. This finding has important implications for safety standards, which are currently based only on adult head models.
Min ST, Redelmeier DA · 1998
Researchers analyzed car accident data from Toronto between 1984-1993 to see if cellular phone use correlated with increased crashes. They found that areas with the biggest increases in collision rates actually had the smallest increases in phone usage. The study concluded that cellular phones' effects on driving safety are too small to detect using this type of population-level analysis.
Mann et al. · 1998
Researchers exposed healthy volunteers to 900 MHz electromagnetic fields (similar to older cell phones) while they slept and measured hormone levels throughout the night. They found a small, temporary increase in cortisol (stress hormone) right after exposure began, but no effects on growth hormone, reproductive hormones, or melatonin. The study suggests our bodies may quickly adapt to this type of EMF exposure.
Mann, K, Roschke, J, Connemann, B, Beta, H · 1998
Researchers monitored heart rate patterns during sleep in healthy adults exposed to radiofrequency fields from digital mobile phones. They found no changes in heart rate variability or the balance between the sympathetic and parasympathetic nervous systems (the body's automatic stress and rest responses) during EMF exposure compared to placebo conditions. The study suggests that weak pulsed RF fields from mobile phones don't disrupt the heart's natural rhythm control during sleep.
Malyapa RS et al. · 1998
Researchers exposed rats to 2450 MHz microwave radiation (the same frequency used in microwave ovens and some WiFi devices) for 2 hours to see if it would damage DNA in brain cells, as a previous study had suggested. They found no DNA damage in either the brain's cortex or hippocampus regions, contradicting the earlier research. This study suggests that short-term exposure to this type of radiation at moderate levels may not cause immediate genetic damage to brain cells.
Malyapa RS et al. · 1998
Researchers exposed rats to microwave radiation at 2450 MHz (the same frequency used in microwave ovens) for 2 hours to test whether it causes DNA breaks in brain cells. They found no DNA damage in either the brain's cortex or hippocampus regions, contradicting an earlier study that reported such damage. This suggests that short-term exposure to this type of microwave radiation at moderate levels may not harm brain cell DNA.
Szmigielski et al. · 1998
Polish researchers studied 61 workers exposed to radiofrequency EMF at radio stations and compared their daily blood pressure and heart rate patterns to 42 unexposed workers. They found that EMF exposure disrupted the natural daily rhythms of both blood pressure and heart rate, with higher exposure levels causing more pronounced effects. This suggests that radiofrequency radiation may interfere with the body's autonomic nervous system, which controls these vital functions.
Hocking, B · 1998
Researchers surveyed 40 mobile phone users who experienced unusual symptoms like burning sensations and dull aches in their head and ears during or after phone calls. These symptoms typically started within minutes of use and lasted up to an hour afterward, with 75% of cases linked to digital phones. The study found that most people got relief by changing how they used their phones or switching to different devices.
Hanson Mild et al. · 1998
Swedish and Norwegian researchers compared symptoms between users of older analog mobile phones (NMT) and newer digital phones (GSM) in a large study of over 17,000 people. Surprisingly, they found that digital phone users actually reported fewer symptoms like warmth sensations around the ear compared to analog users, contradicting their initial hypothesis. However, both phone types showed a clear pattern: the more people talked on their phones, the more they experienced symptoms like headaches, fatigue, and ear warmth.
Grisanti G et al. · 1998
Italian researchers studied how cellular phone radiation affects the inner ear by measuring otoacoustic emissions (tiny sounds the ear produces naturally). They found that the electromagnetic fields from phones altered these natural ear responses in nearly all test subjects. This suggests that phone radiation can interfere with normal inner ear function, potentially affecting hearing.
Freude, G, Ullsperger, P, Eggert ,S, Ruppe, I · 1998
German researchers studied how cell phone radiation affects brain wave patterns by having men perform simple finger movements and complex visual tasks while exposed to phone emissions. They found that radiation significantly altered slow brain potentials (electrical patterns that prepare the brain for action) during the demanding cognitive task, but not during simple movements. This suggests cell phone radiation can interfere with brain electrical activity during mentally challenging activities, even when performance appears normal.
Eulitz, C, Ullsperger, P, Freude, G, Elbert ,T · 1998
German researchers examined how mobile phone radiation affects brain activity by measuring electrical responses while people listened to sounds. They found that phone radiation altered specific patterns of brain activity, particularly in higher frequency brain waves when people were actively processing important sounds. This suggests mobile phones can directly change how our brains process information.
Duan L, Shan Y, Yu X · 1998
Chinese researchers tested brain function in workers exposed to high-frequency electromagnetic radiation using standardized tests recommended by the World Health Organization. They found that exposed workers scored significantly lower on multiple brain performance measures compared to unexposed controls, and these changes correlated with symptoms of neurasthenia (a condition involving mental fatigue and cognitive difficulties). This suggests that occupational exposure to high-frequency EMF can measurably impair cognitive function.
Ding G, Xie X, Zhang L et al. · 1998
Researchers exposed rats to electromagnetic pulses and examined brain tissue to see how it affected nitric oxide synthase (NOS), an enzyme crucial for learning and memory. They found that EMF exposure significantly reduced NOS activity in the hippocampus (the brain's memory center) for up to 48 hours after exposure. This reduction in brain chemistry directly correlates with the learning and memory problems that EMF exposure causes in laboratory animals.
Braune, S, Wrocklage, C, Raczek, J, Gailus, T, Lucking, CH · 1998
German researchers exposed 10 healthy volunteers to GSM 900 MHz cell phone radiation for 35 minutes while continuously monitoring their blood pressure and heart rate. They found that resting blood pressure increased during exposure to the phone's electromagnetic field compared to a placebo condition. This suggests that even short-term exposure to cell phone radiation can affect cardiovascular function in healthy individuals.