3,138 Studies Reviewed. 77.4% Found Biological Effects. The Evidence is Clear.
All Exposure Types

SAR (Specific Absorption Rate)

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Specific Absorption Rate (SAR) measures the rate at which RF energy is absorbed by body tissue, expressed in watts per kilogram (W/kg). SAR is used to rate cell phones and other devices held against the body. The FCC limit for cell phones is 1.6 W/kg averaged over 1 gram of tissue.

Concern Level Thresholds

Based on Building Biology Institute guidelines (W/kg (watts per kilogram)):

No Concern
< 0.4 W/kg
Slight Concern
0.4 – 1.0 W/kg
Severe Concern
1.0 – 1.6 W/kg
Extreme Concern
> 1.6 W/kg (FCC limit)

See where common exposures fall on the scale:

Your RF Exposure in ContextA logarithmic scale showing your reading relative to Building Biology concern thresholds and FCC regulatory limits.Your RF Exposure in ContextNo ConcernSlightSevereExtreme0.0010.010.1FCC Limit 0.00110 W/kg

Showing 871 studies with measured sar (specific absorption rate) exposure

Cellular Effects107 citations

Changes in cellular proteins due to environmental non-ionizing radiation. I. Heat-shock protiens

S. Kwee, P. Raskmark & S. Velizarov · 2001

Danish researchers exposed human cells to weak 960 MHz microwave radiation (similar to cell phones) at extremely low power levels for 20 minutes. They found that cells produced significantly more heat-shock proteins (Hsp-70), which are cellular stress markers, even though the radiation was too weak to cause any heating. This suggests that cells can detect and respond to radiofrequency radiation through non-thermal biological mechanisms.

DNA damage in Molt-4 T- lymphoblastoid cells exposed to cellular telephone radiofrequency fields in vitro.

Phillips et al. · 1998

Researchers exposed immune system cells to radiofrequency radiation from cell phone signals at extremely low power levels for 2 to 21 hours. They found that very low exposures actually reduced DNA damage, while slightly higher exposures increased DNA breaks in the cellular genetic material. This suggests that even minimal RF radiation can alter DNA integrity in immune cells, though the effects varied depending on the specific exposure level.

Effects of modulated and continuous microwave irradiation on the morphology and cell surface negative charge of 3T3 fibroblasts.

Somosy Z, Thuroczy G, Kubasova T, Kovacs J, Szabo LD · 1991

Researchers exposed mouse cells to microwave radiation at 2450 MHz to compare pulsed versus continuous waves. Pulsed microwaves caused more cellular damage and structural changes than continuous waves at identical power levels, suggesting that how EMF is delivered affects biological impact.

Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions.

Dasdag S, Taş M, Akdag MZ, Yegin K. · 2014

Turkish researchers exposed male rats to Wi-Fi radiation (2.4 GHz) for 24 hours a day over an entire year to study effects on reproductive health. They found that this chronic exposure caused sperm head defects to increase and reproductive organs to shrink, including the epididymis and seminal vesicles. The study suggests that long-term Wi-Fi exposure at levels similar to everyday use may harm male fertility.

Cellular EffectsNo Effects Found

Human keratinocytes in culture exhibit no response when exposed to short duration, low amplitude, high frequency (900 MHz) electromagnetic fields in a reverberation chamber.

Roux D et al. · 2011

Researchers exposed human skin cells (keratinocytes) to 900 MHz radiofrequency radiation similar to cell phone signals for 10 minutes at very low power levels. They found essentially no biological effects, with only 20 out of 47,000 genes showing minor changes that weren't confirmed in follow-up testing. This suggests that brief, low-level cell phone radiation exposure may not significantly affect skin cells in laboratory conditions.

Brain & Nervous SystemNo Effects Found

Influence of a 902.4 MHz GSM signal on the human visual system: investigation of the discrimination threshold.

Irlenbusch L et al. · 2007

Researchers exposed 33 people to GSM mobile phone signals near their eyes to test whether radiofrequency radiation affects visual sensitivity (the ability to detect light differences). Using exposure levels similar to holding a phone close to your face, they found no measurable changes in visual discrimination abilities during 30-minute exposure sessions. This suggests that typical mobile phone use doesn't immediately impair basic visual function.

Brain & Nervous SystemNo Effects Found

Influence of a 902.4 MHz GSM signal on the human visual system: Investigation of the discrimination threshold

Irlenbusch L et al. · 2007

German researchers exposed 33 people to cell phone radiation at 902.4 MHz for 30 minutes to see if it affected their ability to detect light (visual discrimination threshold). They found no statistically significant changes in visual sensitivity between real exposure and fake exposure sessions. This suggests that brief GSM radiation exposure at typical power levels doesn't immediately impair basic visual function.

CardiovascularNo Effects Found

Character of the effect of microwave on conduction velocity of frog ventricular muscle.

Yee KC, Chou CK, Guy AW · 1994

Researchers exposed isolated frog hearts to 2.45 GHz microwave radiation (the same frequency used in microwave ovens and WiFi) for 2 hours at various power levels to see if it affected how electrical signals travel through heart muscle. They found no changes in the speed of electrical conduction through the heart tissue at any exposure level tested, including levels much higher than typical human exposure from wireless devices.

SAR in a child voxel phantom from exposure to wireless computer networks (Wi-Fi).

Findlay RP, Dimbylow PJ. · 2010

British researchers used computer modeling to calculate how much radiofrequency energy (called SAR) a 10-year-old child's body would absorb from Wi-Fi devices operating at typical household distances. They found that Wi-Fi exposure produced SAR levels of 3.99-5.7 milliwatts per kilogram in the child's torso and head, which is less than 1% of what a cell phone produces. This study provides important baseline data on children's Wi-Fi exposure levels.

The effects of mobile phones on apoptosis in cerebral tissue: an experimental study on rats.

Yilmaz A et al. · 2014

Researchers exposed rats to mobile phone radiation at typical usage levels for four weeks, then examined brain tissue for signs of cell death (apoptosis). They found significantly increased levels of proteins that control cell death in the exposed rats compared to unexposed controls. This suggests that mobile phone radiation may trigger cellular stress responses in brain tissue at exposure levels similar to everyday phone use.

The effects of mobile phones on apoptosis in cerebral tissue: an experimental study on rats

Yilmaz A et al. · 2014

Turkish researchers exposed rats to mobile phone radiation at levels similar to everyday phone use for 4 weeks, then examined brain tissue for signs of programmed cell death (apoptosis). The exposed rats showed significantly increased levels of proteins that trigger cell death compared to unexposed controls. This suggests that mobile phone radiation may cause brain cells to die prematurely, even at the low power levels typical of normal phone use.

Cellular EffectsNo Effects Found

An investigation of the effects of TETRA RF fields on intracellular calcium in neurones and cardiac myocytes.

Green AC et al. · 2005

Researchers exposed brain and heart cells to TETRA radio signals (the frequency used by emergency services) to see if it disrupted calcium levels inside the cells. Calcium is crucial for cell function, especially in neurons and heart muscle. The study found no significant changes in calcium activity at any exposure level tested, suggesting TETRA fields don't interfere with this fundamental cellular process.

Sleep & Circadian RhythmNo Effects Found

1800 MHz electromagnetic field effects on melatonin release from isolated pineal glands.

Sukhotina I, Streckert JR, Bitz AK, Hansen VW, Lerchl A · 2006

Researchers exposed isolated hamster pineal glands (which produce melatonin, the sleep hormone) to cell phone radiation at 1800 MHz for 7 hours at various power levels. Surprisingly, they found that moderate exposure levels actually increased melatonin production, while only the highest level (which caused tissue heating) suppressed it. This challenges the widely-discussed theory that cell phone radiation disrupts sleep by reducing melatonin.

Cancer & Tumors449 citations

Lymphomas in E mu-Pim1 transgenic mice exposed to pulsed 900 MHZ electromagnetic fields.

Repacholi et al. · 1997

Scientists exposed genetically cancer-prone mice to 900 MHz radiofrequency fields (similar to cell phone signals) for 30 minutes twice daily for up to 18 months. The exposed mice developed lymphoma (a type of cancer) at 2.4 times the rate of unexposed mice. This suggests that cell phone-type radiation may accelerate cancer development in those already genetically susceptible.

Reactive oxygen species elevation and recovery in Drosophila bodies and ovaries following short-term and long-term exposure to DECT base EMF

Manta AK, Stravopodis DJ, Papassideri IS, Margaritis LH. · 2014

Researchers exposed fruit flies to cordless phone base station radiation and found cellular damage markers doubled in fly bodies after 6 hours. Female reproductive organs showed even faster responses, with damage markers increasing 2.5 times after just 1 hour of exposure.

Reactive oxygen species elevation and recovery in Drosophila bodies and ovaries following short-term and long-term exposure to DECT base EMF.

Manta AK, Stravopodis DJ, Papassideri IS, Margaritis LH · 2013

Researchers exposed fruit flies to radiation from cordless phone base stations. The flies showed doubled levels of cell-damaging molecules within hours, even at very low radiation levels. This suggests common household wireless devices may cause cellular stress below current safety standards.

Effects of long-term exposure to 900 megahertz electromagnetic field on heart morphology and biochemistry of male adolescent rats.

Kerimoğlu G et al. · 2016

Researchers exposed adolescent male rats to cell phone-level radiation (900 MHz) for one hour daily during their development and examined their hearts as adults. The exposed rats showed significant heart damage including increased oxidative stress, structural changes to heart muscle cells, and higher rates of cell death compared to unexposed controls. This suggests that EMF exposure during critical developmental periods may cause lasting cardiovascular damage.

Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats.

Liu Q, Si T, Xu X, Liang F, Wang L, Pan S. · 2015

Researchers exposed male rats to 900 MHz cell phone radiation for two hours daily over 50 days. Sperm cell death increased 91% compared to unexposed rats, with radiation triggering cellular damage through increased free radicals and decreased antioxidant defenses, demonstrating clear reproductive harm.

Oxidative Stress104 citations

GSM Base Station Electromagnetic Radiation and Oxidative Stress in Rats.

Yurekli AI et al. · 2006

Turkish researchers exposed rats to cell tower radiation at 945 MHz for an unspecified duration and measured markers of oxidative stress (cellular damage from free radicals). They found that exposure at power levels well below current safety limits significantly increased harmful oxidative markers and decreased protective antioxidants in the rats. This suggests that even low-level electromagnetic radiation from cell towers may trigger cellular stress responses.

Long-term electromagnetic exposure of developing neuronal networks: A flexible experimental setup.

Oster S et al. · 2016

German researchers developed a sophisticated laboratory system to expose developing rat brain neurons to 900 MHz radiofrequency radiation (similar to cell phone frequencies) for weeks at a time. The study focused on creating reliable equipment to test whether wireless radiation affects developing brain tissue, using exposure levels of 362 milliwatts per kilogram. While the paper describes the experimental setup in detail, it doesn't report specific biological effects, serving instead as a foundation for future research on how RF radiation might impact the developing nervous system.