Christensen HC et al. · 2004
Danish researchers studied 106 people with acoustic neuroma (a non-cancerous brain tumor near the ear) and 212 healthy controls to see if cell phone use increased tumor risk. They found no increased risk of developing these tumors, even among people who used cell phones for 10 years or more. Importantly, tumors didn't occur more often on the side of the head where people typically held their phones.
Aran JM et al. · 2004
French researchers exposed guinea pigs' ears to cell phone radiation (900 MHz GSM) for 1 hour daily over 2 months at power levels up to 4 times higher than typical phone use. They found no damage to hearing function or inner ear structures, even when examining the ears immediately after exposure and 2 months later. The study also tested isolated ear tissue from newborn rats and found no cellular damage under microscopic examination.
Strayer DL, Drews FA. · 2004
University of Utah researchers studied how hands-free cell phone conversations affect driving performance in both younger and older adults using driving simulators. They found that phone conversations made reactions 18% slower, increased following distance by 12%, and doubled the number of rear-end collisions for drivers of all ages. The impairment was so significant that young drivers talking on phones performed as poorly as older drivers who weren't using phones at all.
Pedersen W. · 2004
Norwegian researchers studied 10,926 teenagers to examine how mobile phone and internet use relates to sexual behavior. They found a striking pattern: less than 10% of teens who didn't use these technologies reported having sexual intercourse, while two-thirds of the heaviest users did. This association remained strong even after accounting for age, family background, and other factors, suggesting mobile technology may significantly influence teenage sexual development.
Papageorgiou CC et al. · 2004
Researchers exposed 19 people to 900 MHz cell phone signals while measuring their brain activity with EEG. They found that men and women responded differently to the radiation - men's brain activity decreased while women's increased during exposure. Memory performance wasn't affected, but the study reveals that cell phone radiation affects male and female brains in opposite ways.
Martinez-Burdalo M, Martin A, Anguiano M, Villar R · 2004
Researchers used computer modeling to compare how much cell phone radiation is absorbed by adult versus child head models at common cell phone frequencies. They found that while smaller heads absorb less total radiation, children's brains absorb a higher percentage of that energy due to their thinner skulls and smaller head size. This suggests children may face greater brain exposure to cell phone radiation than current safety standards account for.
Maby E et al. · 2004
French researchers studied how GSM cell phone radiation affects brain activity by measuring auditory evoked potentials (electrical signals the brain produces when hearing sounds) in both healthy people and epileptic patients. They found that exposure to GSM radiofrequency radiation measurably altered brain wave patterns, reducing the amplitude of a key brain response called N100 and speeding up response times in healthy subjects. This demonstrates that cell phone radiation can directly influence how the brain processes information, even though the researchers couldn't determine if these changes affect actual brain function.
Lonn S et al. · 2004
Researchers tracked brain tumor rates across four Nordic countries from 1969 to 1998, covering the period when mobile phones were first introduced. They found that brain tumor incidence increased in the late 1970s and early 1980s due to improved diagnostic methods, but remained stable after 1983 despite growing mobile phone use. This suggests that better medical imaging, not mobile phones, explains the earlier increases in reported brain tumors.
Lesch MF, Hancock PA. · 2004
Researchers tested whether drivers using cell phones are aware of how much their driving performance suffers. They found that while confident male drivers performed better, confident female drivers (especially older women) actually performed worse, with brake response times slowing by 0.38 seconds compared to just 0.07-0.10 seconds for other groups. This suggests many drivers, particularly women, don't realize how much cell phone use impairs their driving ability.
Kimata H. · 2004
Researchers studied patients with atopic dermatitis (a chronic skin condition) to see how mobile phone use affects their allergic responses and stress markers. They found that writing messages on a mobile phone increased stress hormones and worsened allergic skin reactions, while watching comedy videos beforehand prevented these negative effects. This suggests that mobile phone use can trigger stress responses that worsen allergic conditions, but positive emotions may provide protection.
Ilhan A et al. · 2004
Turkish researchers exposed rats to 900 MHz mobile phone radiation for one hour daily over seven days and found significant oxidative stress damage in brain tissue. The damage included increased harmful molecules and decreased protective antioxidant enzymes. However, when rats were pre-treated with Ginkgo biloba extract, this brain damage was completely prevented, suggesting that antioxidants may protect against EMF-induced cellular harm.
Hamblin DL, Wood AW, Croft RJ, Stough C. · 2004
Researchers exposed 12 people to GSM mobile phone radiation for one hour while they performed listening tasks and measured their brain activity using EEG. The study found that phone radiation altered several brain wave patterns (N100 and P300 responses) and slowed reaction times, particularly in brain areas closest to where the phone was positioned. These changes suggest that mobile phone radiation can directly affect how the brain processes auditory information.
Grant H, Heirman D, Kuriger G, Ravindran MM. · 2004
Researchers tested whether cell phones could interfere with Cyberonics neural stimulators (implanted devices that help treat conditions like epilepsy and depression). After conducting 1,080 separate tests, they found no electromagnetic interference between the phones and the neural stimulators. This suggests that people with these specific implanted devices can safely use cell phones without worrying about disrupting their medical treatment.
Charlton SG. · 2004
Researchers tested how cell phone use affects drivers' ability to respond to curve warnings on roads using a driving simulator. They found that talking on a cell phone made drivers less responsive to road hazards - they drove faster and had slower reaction times, especially on less dangerous curves. This shows that cell phone conversations create measurable cognitive interference that compromises driving safety.
Bergamaschi A, Magrini A, Ales G, Coppetta L, Somma G. · 2004
Italian researchers studied 2,598 mobile phone company employees to see if heavy phone use affects thyroid function. They found that workers using phones more than 33 hours per month were significantly more likely to have suppressed thyroid-stimulating hormone (TSH) levels, a marker of thyroid dysfunction. However, the researchers couldn't determine whether this effect came from the phone's electromagnetic radiation or from job-related stress.
Berg G, Schuz J, Samkange-Zeeb F, Blettner M. · 2004
German researchers tracked actual cell phone radiation exposure using specially modified phones that recorded power output during calls, then compared this data to what people reported about their phone use. They found that people's self-reported number of calls was a reasonable predictor of their total radiation exposure, with call frequency explaining about 23% of the variation in cumulative power exposure. This validation study was part of the larger INTERPHONE investigation examining links between cell phone use and brain tumors.
Barkana Y, Zadok D, Morad Y, Avni I. · 2004
Researchers tested how hands-free cell phone conversations affect visual attention by having 41 people take visual field tests while talking on phones. They found that phone conversations significantly reduced visual awareness - participants missed 160% more visual targets and had reaction times that were 15% slower. This suggests that even hands-free phone use creates dangerous attention deficits that could impact driving safety.
Al-Khlaiwi T, Meo SA. · 2004
Saudi researchers surveyed 437 mobile phone users to examine connections between phone use and common health symptoms. They found that mobile phone users reported headaches (21.6% of users), sleep disturbances (4%), tension (3.9%), fatigue (3%), and dizziness (2.4%). The study suggests these symptoms may be linked to mobile phone radiation exposure, though the research didn't measure specific radiation levels.
Ilhan A et al. · 2004
Researchers exposed rats to cell phone radiation (900 MHz) for one hour daily over seven days, finding it caused brain cell damage through oxidative stress. Ginkgo biloba extract prevented this damage by protecting the brain's natural antioxidant systems, suggesting potential protection against phone radiation effects.
La Regina M et al. · 2003
Researchers exposed 480 rats to cell phone radiation for 4 hours daily over 2 years to see if it caused cancer. They tested two types of signals (FDMA and CDMA) at levels similar to what your brain absorbs during phone calls. The study found no increase in tumors of any type compared to unexposed rats.
Kramarenko AV, Tan U. · 2003
Ukrainian researchers used specialized brain monitoring equipment to measure how cell phone radiation affects brain waves in awake adults and children. They found that mobile phones caused abnormal slow-wave patterns to appear in the brain within 20-40 seconds of exposure, with children showing stronger effects that appeared faster than in adults. These brain wave changes disappeared 15-20 minutes after turning off the phone, suggesting cell phones can temporarily alter normal brain activity.
Kizilay A et al. · 2003
Turkish researchers exposed rats to mobile phone electromagnetic fields for one hour daily over 30 days to test whether this would damage their hearing. Using sensitive hearing tests called distortion product otoacoustic emissions (DPOAEs), they found no measurable hearing damage in either adult rats or developing newborn rats. The study suggests that chronic mobile phone EMF exposure at these levels does not impair hearing function in the outer ear, middle ear, or cochlea (the main hearing organ).
Kainz W, Alesch F, Chan DD. · 2003
Researchers tested whether GSM mobile phones interfere with deep brain stimulators (devices implanted in the brain to treat conditions like Parkinson's disease) by exposing the ITREL-III stimulator to signals from 20 different phones in laboratory conditions. They found no interference at normal phone power levels, though the device could be disrupted at much higher power levels than phones actually emit. The study concluded that patients with these brain implants can safely use GSM phones with basic precautions.
Kahn AA et al. · 2003
Irish researchers studied 73 brain tumor patients to see if mobile phone users developed tumors on the same side of their head where they held their phone. They compared 50 mobile phone users with 23 non-users and found no pattern linking phone use to tumor location. This suggests that if mobile phones cause brain tumors, the effect isn't simply related to which side of the head receives the most radiation exposure.
Haarala C et al. · 2003
Researchers used PET brain scans to measure blood flow in 14 people while they were exposed to a 902 MHz mobile phone signal. They found decreased blood flow in the auditory areas of the brain, but not in the areas where EMF exposure was strongest. The researchers concluded this was likely due to subtle sounds from the phone rather than the electromagnetic radiation itself.