Croft R et al. · 2002
Australian researchers measured brain activity in 24 people while they used active mobile phones for three 20-minute sessions. They found that phone use changed brain wave patterns in multiple ways - decreasing slow waves on the right side of the brain, increasing faster waves in the back, and altering how the brain responds to sounds. The changes got stronger the longer people were exposed, suggesting that phone radiation directly affects how our brains function.
Stagg RB et al. · 2001
Researchers exposed rats to cell phone radiation at levels up to 5 W/kg (similar to older phones held directly against the head) while measuring stress hormones and brain activity markers. The study found no differences in stress responses between animals exposed to the radiation versus those that were only restrained, suggesting the radiation itself didn't cause additional stress at these exposure levels.
Sandstrom M, Wilen J, Oftedal G, Hansson Mild K · 2001
Researchers compared symptoms between users of older analog phones (NMT) and newer digital phones (GSM) among nearly 17,000 people in Sweden and Norway. Contrary to initial reports suggesting digital phones caused more symptoms, the study found GSM users actually experienced fewer symptoms like ear warmth and headaches. However, people who talked longer on either type of phone reported more symptoms overall.
Santini R et al. · 2001
French researchers surveyed 161 engineering students and workers about symptoms they experienced while using digital cell phones operating at 900 MHz and 1800 MHz frequencies. They found that users of the higher frequency phones (1800 MHz) reported significantly more concentration difficulties, while women experienced more sleep disturbances than men. Phone users also reported physical discomfort including ear warmth and pricking sensations that increased with longer daily use.
Lebedeva NN et al. · 2001
Researchers monitored brain activity in sleeping people exposed to cell phone radiation for 8 hours, comparing it to nights without exposure. They found that cell phone electromagnetic fields altered brain wave patterns during sleep, specifically increasing alpha waves (brain waves associated with relaxed wakefulness) and changing how sleep stages progressed. This suggests that even during sleep, when phones aren't actively being used nearby, the radiation can still influence normal brain function.
Jech R et al. · 2001
Researchers exposed 22 patients with narcolepsy (a sleep disorder causing excessive daytime sleepiness) to cell phone radiation for 45 minutes and measured their brain activity during cognitive tasks. They found that the electromagnetic fields improved the patients' reaction times by 20 milliseconds and enhanced brain responses to visual stimuli, suggesting the radiation temporarily reduced their sleepiness and improved mental performance.
Lyskov E, Sandström M, Mild KH · 2001
Researchers exposed 20 people with electromagnetic hypersensitivity and 20 healthy controls to magnetic fields while monitoring their bodies. Magnetic fields didn't affect either group, but hypersensitive individuals showed different heart rate and stress patterns, suggesting they may have heightened sensitivity to environmental stressors generally.
Wagner P et al. · 2000
German researchers exposed 20 healthy men to extremely high levels of cell phone radiation (100 times stronger than typical phone use) during sleep to see if it affected their brain waves and sleep patterns. Despite using this intense exposure level, they found no measurable changes to sleep quality or brain activity during sleep. This contradicts earlier studies that found sleep disruption at much lower radiation levels.
Oftedal G, Wilen J, Sandstrom M, Mild KH · 2000
Researchers surveyed 17,000 mobile phone users across Norway and Sweden to document symptoms people experienced while using their phones. They found that 31% of Norwegian users and 13% of Swedish users reported at least one symptom connected to phone use, with the most common being warmth around the ear, burning facial sensations, and headaches that typically began during calls and lasted up to 2 hours. While nearly half of those experiencing symptoms took steps to reduce them, few sought medical care, suggesting these effects were bothersome but not considered serious health problems by users.
Hietanen M, Kovala T, Hamalainen AM · 2000
Finnish researchers measured brain wave activity (EEG) in 19 volunteers while they were exposed to radiation from five different cell phones operating at 900 MHz or 1800 MHz for 20 minutes each. They found one small change in brain activity with one phone, but no consistent patterns across the other phones or brain wave frequencies. The researchers concluded this single finding was likely due to random chance rather than actual effects from the phone radiation.
Krause CM et al. · 2000
Finnish researchers tested how cell phone radiation affects brain activity during memory tasks by measuring brainwaves in 24 people while they performed visual memory exercises. They found that 902 MHz cell phone radiation altered specific brainwave patterns (around 8 Hz frequency) during cognitive processing, but only under certain memory load conditions. This suggests that cell phone radiation can directly interfere with the brain's electrical activity while you're thinking and remembering.
Krause CM et al. · 2000
Finnish researchers exposed 16 people to 902 MHz cell phone radiation while they performed memory tasks, measuring brain activity through EEG recordings. They found that cell phone radiation significantly altered brain wave patterns during memory encoding and retrieval, even though it didn't affect resting brain activity. This suggests that EMF exposure specifically disrupts the brain's electrical activity when it's actively working on cognitive tasks.
Lebedeva NN et al. · 2000
Russian researchers exposed 24 volunteers to cell phone radiation at 902.4 MHz for 15 minutes while measuring their brain activity using EEG. They found significant changes in brain electrical patterns during and after exposure, with the brain showing increased activation that persisted for 30 minutes after the phone was turned off. This demonstrates that cell phone radiation directly alters how the brain functions, even at relatively low power levels.
Huber R et al. · 2000
Swiss researchers exposed healthy young men to cell phone radiation (900 MHz) for 30 minutes before bedtime and monitored their brain activity during sleep. They found that the radiation exposure altered brainwave patterns during deep sleep, with specific frequency bands showing increased activity that persisted hours after the exposure ended. This demonstrates that cell phone radiation can cause measurable changes to brain function that outlast the actual exposure period.
Preece et al. · 1999
Researchers tested whether mobile phone signals at 915 MHz affect brain function by having 36 people perform cognitive tests while exposed to simulated phone radiation. They found that exposure made people react faster on choice reaction time tests, but had no effect on memory tasks. The faster reaction times suggest the phone signals may be affecting a specific brain region called the angular gyrus, which processes visual and speech information.
de Seze R, Ayoub J, Peray P, Miro L, Touitou Y · 1999
French researchers exposed 38 young men to cell phone radiation (GSM 900 MHz and DCS 1800 MHz) for 2 hours daily over 4 weeks to test whether it would disrupt melatonin, the hormone that regulates sleep cycles. They found no changes in melatonin patterns during or after exposure. This suggests that typical cell phone use may not directly interfere with the body's natural sleep hormone production.
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.
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.
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.
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.
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.
Bergdahl J, Tillberg A, Stenman E. · 1998
Swedish researchers examined 28 patients who reported health symptoms they believed were caused by electricity or computer screens (visual display units). The study found these patients had various dental and oral health problems, including jaw dysfunction, mouth burning, and reduced saliva production. While the study couldn't prove electricity caused these symptoms, it suggests that dental health issues might contribute to the suffering experienced by people who report electrical sensitivity.
Vollrath L, Spessert R, Kratzsch T, Keiner M, Hollmann H · 1997
German researchers exposed rats and hamsters to 900 MHz radio frequency fields (similar to early cell phones) for up to 6 hours to see if it would affect their pineal glands, which produce the sleep hormone melatonin. They found no changes in melatonin production or pineal gland structure at any exposure level tested. This suggests that short-term RF exposure at these levels doesn't disrupt the body's natural sleep-wake cycle regulation.
Roschke, J, Mann, K · 1997
German researchers exposed 34 healthy men to cell phone radiation (900 MHz) for 3.5 minutes while measuring their brain activity with EEG sensors. They found no detectable changes in brain wave patterns during the short exposure period compared to when the phone was turned off. This suggests that brief cell phone use may not immediately alter brain electrical activity in awake, healthy adults.
