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

SAR (Specific Absorption Rate)

Share:

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

Brain & Nervous SystemNo Effects Found

No influence of acute RF exposure (GSM-900, GSM-1800, and UMTS) on mouse retinal ganglion cell responses under constant temperature conditions.

Ahlers MT, Ammermüller J. · 2013

German researchers exposed isolated mouse retina cells to mobile phone radiation (GSM-900, GSM-1800, and UMTS) at various power levels while carefully controlling temperature. They found no changes in how these vision-critical cells responded to light stimuli, even at radiation levels 10 times higher than typical phone use. This suggests mobile phone radiation doesn't directly interfere with retinal function under controlled laboratory conditions.

2.45 GHz microwave irradiation-induced oxidative stress affects implantation or pregnancy in mice, Mus musculus.

Shahin S et al. · 2013

Researchers exposed female mice to 2.45 GHz microwave radiation (the same frequency as WiFi and microwave ovens) for 2 hours daily over 45 days at very low power levels. The exposed mice showed significantly reduced implantation sites for embryos, along with increased DNA damage in brain cells, elevated stress markers in blood, and disrupted hormone levels. This suggests that even low-level microwave radiation can interfere with reproduction and pregnancy through oxidative stress mechanisms.

2.45 GHz microwave irradiation-induced oxidative stress affects implantation or pregnancy in mice, Mus musculus.

Shahin S et al. · 2013

Researchers exposed female mice to 2.45 GHz microwave radiation (the same frequency used by WiFi and microwave ovens) for 2 hours daily over 45 days, using power levels far below current safety standards. The exposed mice showed significantly reduced pregnancy success, increased DNA damage in brain cells, and widespread oxidative stress throughout their bodies. This suggests that even low-level microwave radiation may interfere with reproductive health through cellular damage mechanisms.

Influence of electromagnetic field (1800 MHz) on lipid peroxidation in brain, blood, liver and kidney in rats

Bodera P et al. · 2015

Researchers exposed rats to 1800 MHz radiofrequency radiation (the same frequency used in cell phones) for 15 minutes, five times daily, and measured oxidative damage in their organs. They found increased lipid peroxidation (cellular damage from oxidation) in the brain, blood, and kidneys of exposed animals. This suggests that repeated cell phone-frequency radiation exposure may cause oxidative stress damage to vital organs.

Immunotropic influence of 900 MHz microwave GSM signal on human blood immune cells activated in vitro.

Stankiewicz W et al. · 2006

Researchers exposed human immune cells to 900 MHz microwave radiation (similar to GSM cell phone signals) at very low power levels and found that the radiation significantly increased immune cell activity. The exposed cells showed stronger responses to immune stimulants compared to unexposed control cells. This suggests that even weak microwave radiation can alter how our immune system functions.

Immunotropic influence of 900 MHz microwave GSM signal on human blood immune cells activated in vitro.

Stankiewicz W et al. · 2006

Polish researchers exposed human immune cells to 900 MHz GSM cell phone signals at very low power levels (SAR 0.024 W/kg) and found that the microwave exposure significantly increased immune cell activity. The exposed cells showed stronger responses to immune stimulants and higher activity levels compared to unexposed control cells. This suggests that even low-level cell phone radiation can alter how your immune system functions at the cellular level.

Effects of GSM and UMTS mobile telephony signals on neuron degeneration and blood-brain barrier permeation in the rat brain.

Poulletier de Gannes F et al. · 2017

French researchers exposed rats to cell phone radiation (GSM and UMTS signals) for 4 weeks and found that high exposure levels caused the blood-brain barrier to leak 50 days after exposure ended. The blood-brain barrier normally protects the brain from harmful substances in the blood, but this protective shield became compromised at radiation levels equivalent to what humans might experience with very high cell phone use.

Long term and excessive use of 900 MHz radiofrequency radiation alter microRNA expression in brain.

Dasdag S et al. · 2015

Researchers exposed rats to cell phone radiation (900 MHz) for 3 hours daily over an entire year to study effects on microRNAs - tiny molecules that control gene activity in the brain. The radiation significantly decreased levels of one specific microRNA (miR-107) that helps regulate brain cell function. This finding suggests that long-term cell phone use may disrupt the brain's genetic control systems, potentially leading to neurological problems.

Long term and excessive use of 900 MHz radiofrequency radiation alter microrna expression in brain.

Dasdag S et al. · 2014

Turkish researchers exposed rats to cell phone radiation (900 MHz) for 3 hours daily over an entire year and found it altered microRNA in brain tissue. MicroRNAs are tiny molecules that control gene activity and play crucial roles in brain function, cell growth, and death. This study demonstrates that chronic radiofrequency exposure can disrupt these fundamental cellular control mechanisms in the brain.

Long-term effects of 900 MHz radiofrequency radiation emitted from mobile phone on testicular tissue and epididymal semen quality.

Tas M et al. · 2014

Turkish researchers exposed male rats to 900 MHz cell phone radiation for 3 hours daily over one full year to study reproductive effects. While sperm count and movement weren't affected, the radiation caused structural damage to testicular tissue, including thinner protective layers and lower tissue health scores. This suggests that chronic cell phone radiation exposure may harm male reproductive organs even when basic sperm parameters appear normal.

Cellular Effects103 citations

915 MHz microwaves and 50 Hz magnetic field affect chromatin conformation and 53BP1 foci in human lymphocytes from hypersensitive and healthy persons.

Belyaev IY et al. · 2005

Researchers exposed white blood cells from healthy people and those with electromagnetic sensitivity to cell phone radiation (915 MHz). Both groups showed identical DNA structural changes similar to heat stress, confirming that electromagnetic fields cause measurable biological effects in human cells.

Immune System103 citations

915 MHz microwaves and 50 Hz magnetic field affect chromatin conformation and 53BP1 foci in human lymphocytes from hypersensitive and healthy persons

Belyaev et al. · 2005

Researchers exposed human immune cells to cell phone radiation (915 MHz) and power line magnetic fields. Both exposures caused cellular stress responses similar to heat shock, affecting how DNA is packaged inside cells. This occurred equally in healthy people and those reporting electromagnetic sensitivity.

Microwaves from GSM mobile telephones affect 53BP1 and gamma-H2AX foci in human lymphocytes from hypersensitive and healthy persons.

Markovà E, Hillert L, Malmgren L, Persson BR, Belyaev IY. · 2005

Researchers exposed human immune cells (lymphocytes) to microwave radiation from GSM mobile phones for one hour and found it caused DNA damage markers similar to heat shock. The study examined cells from both healthy people and those who report electromagnetic hypersensitivity, finding similar responses in both groups. This demonstrates that cell phone radiation can trigger cellular stress responses and DNA damage at exposure levels well below current safety standards.

DNA & Genetic DamageNo Effects Found

Frequency of micronuclei in the blood and bone marrow cells of mice exposed to ultra-wideband electromagnetic radiation.

Vijayalaxmi et al. · 1999

Researchers exposed mice to ultra-wideband electromagnetic radiation (a type of wireless signal) for 15 minutes and then examined their blood and bone marrow cells for signs of genetic damage. They found no evidence that the radiation caused DNA damage or other cellular harm compared to unexposed control mice. This suggests that short-term exposure to this specific type of electromagnetic radiation at the tested intensity may not pose immediate genetic risks.

Effect of chronic exposure to a GSM-like signal (mobile phone) on survival of female Sprague-Dawley rats: Modulatory effects by month of birth and possibly stage of the solar cycle.

Bartsch H et al. · 2010

German researchers exposed female rats to cell phone radiation (900 MHz) throughout their lives. Exposed rats lived 9% shorter lives than unexposed rats - about 72-77 fewer days. The radiation levels matched typical cell phone exposure, suggesting chronic use might affect human lifespan.

The toxic effects of mobile phone radiofrequency (940MHz) on the structure of calf thymus DNA.

Hekmat A, Saboury AA, Moosavi-Movahedi AA. · 2012

Researchers exposed DNA samples to mobile phone radiation (940 MHz) and found that the radiation caused permanent structural changes to the DNA molecules. The DNA became less stable, changed shape, and showed signs of damage that persisted even two hours after exposure ended. This suggests that radiofrequency radiation from mobile phones can directly alter DNA structure at the molecular level.

[Autoimmune processes after long-term low-level exposure to electromagnetic fields (the results of an experiment). Part 4. Manifestation of oxidative intracellular stress-reaction after long-term non-thermal EMF exposure of rats]

Grigor'ev IuG et al. · 2010

Researchers exposed rats to WiFi-frequency radiation (2450 MHz) for 7 hours daily over 30 days at non-heating levels. They found clear signs of oxidative stress in blood, indicating cellular damage from harmful free radicals. This suggests low-level microwave exposure can damage cells without heating tissue.

Circadian alterations of reproductive functional markers in male rats exposed to 1800-MHz radiofrequency field.

Qin F et al. · 2014

Researchers exposed male rats to cell phone radiation (1800 MHz) for 2 hours daily over 32 days and found it disrupted their natural body clocks and harmed reproductive function. The radiation reduced testosterone levels, decreased sperm production and movement, and interfered with the normal daily rhythms that regulate these processes. This suggests that the timing of EMF exposure throughout the day may influence how severely it affects male fertility.

The effect of melatonin on body mass and behaviour of rats during an exposure to microwave radiation from mobile phone.

Sokolovic D et al. · 2012

Researchers exposed rats to mobile phone radiation for 4 hours daily over 60 days and found the animals lost significant body weight and developed anxiety-like behaviors including agitation and irritability. When rats were given melatonin (a natural hormone) along with the radiation exposure, these negative effects were largely prevented, suggesting melatonin may offer protective benefits against microwave radiation damage.

Melatonin reduces oxidative stress induced by chronic exposure of microwave radiation from mobile phones in rat brain.

Sokolovic D et al. · 2008

Researchers exposed rats to mobile phone radiation at levels similar to human exposure for up to 60 days and found significant brain damage from oxidative stress - essentially, cellular damage from harmful molecules. When rats were given melatonin (a natural hormone), it partially protected their brains from this radiation damage. This suggests that mobile phone radiation can harm brain cells through oxidative stress, and that melatonin might offer some protection.

Oxidative Stress165 citations

Melatonin reduces oxidative stress induced by chronic exposure of microwave radiation from mobile phones in rat brain.

Sokolovic D et al. · 2008

Researchers exposed rats to mobile phone radiation for 20 to 60 days and found it caused oxidative damage in brain tissue, measured by increased levels of harmful molecules and decreased protective enzyme activity. When the rats were also given melatonin (a natural hormone), it significantly prevented some of this brain damage. This suggests that mobile phone radiation can harm brain cells through oxidative stress, but melatonin may offer some protection.

Neural and behavioral teratological evaluation of rats exposed to ultra-wideband electromagnetic fields.

Cobb BL et al. · 2000

Researchers exposed pregnant rats to ultra-wideband electromagnetic pulses (similar to radar technology) during pregnancy to see if it affected their offspring's development and behavior. The exposed rat pups showed three main differences: they made more stress vocalizations, had slightly enlarged brain structures (hippocampus), and male offspring were less likely to mate as adults. However, the researchers noted these effects might be random findings due to testing many different outcomes.