8,655 Studies Reviewed. 86.9% 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 899 studies with measured sar (specific absorption rate) exposure

Reproductive HealthNo Effects Found

Mobile phone radiation does not induce pro-apoptosis effects in human spermatozoa.

Falzone N, Huyser C, Franken DR, Leszczynski D. · 2010

Researchers exposed human sperm samples to mobile phone radiation at levels of 2.0 and 5.7 W/kg to see if the radiation would trigger cell death (apoptosis) through several biological pathways. They found no statistically significant effects on any of the markers they tested, including DNA damage, oxidative stress, or cellular death signals. This suggests that if mobile phone radiation does harm male fertility as some studies indicate, it's likely through mechanisms other than directly killing sperm cells.

Increased protein synthesis by cells exposed to a 1,800-MHz radio-frequency mobile phone electromagnetic field, detected by proteome profiling.

Gerner C et al. · 2010

Austrian researchers exposed four types of human cells to cell phone radiation (1,800 MHz) at levels similar to what phones emit during calls. After 8 hours of exposure, metabolically active cells showed significantly increased protein production, while inactive cells showed no response. The temperature rise was minimal (less than 0.15°C), indicating this was a non-thermal biological effect of the radiation itself.

Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons

Xu S et al. · 2010

Researchers exposed brain neurons to cell phone-frequency radiation (1800 MHz) at levels similar to heavy phone use and found it damaged the DNA inside cellular powerhouses called mitochondria. The radiation increased markers of DNA damage by 24 hours and reduced the neurons' ability to produce energy. Importantly, the antioxidant melatonin completely prevented this damage, suggesting oxidative stress was the underlying cause.

CardiovascularNo Effects Found

Analysis of proteome response to the mobile phone radiation in two types of human primary endothelial cells.

Nylund R, Kuster N, Leszczynski D · 2010

Researchers exposed human blood vessel cells (endothelial cells) to cell phone radiation at 1800 MHz for one hour at levels similar to what phones emit during calls. They used advanced protein analysis to detect any changes in how the cells functioned. The study found no statistically significant changes in protein expression, suggesting this type of radiation exposure didn't alter cellular activity in these particular cells under these conditions.

CardiovascularNo Effects Found

Analysis of proteome response to the mobile phone radiation in two types of human primary endothelial cells

Nylund R, Kuster N, Leszczynski D · 2010

Researchers exposed two types of human blood vessel cells to 1800 MHz cell phone radiation at levels similar to phone use (SAR 2.0 W/kg) for one hour and examined whether this changed protein production in the cells. They found no statistically significant changes in protein expression compared to unexposed cells. This suggests that short-term cell phone radiation exposure may not immediately alter how these particular blood vessel cells function at the molecular level.

Impact of 1.8-GHz radiofrequency radiation (RFR) on DNA damage and repair induced by doxorubicin in human B-cell lymphoblastoid cells.

Zhijian C et al. · 2010

Researchers exposed human immune cells to cell phone radiation (1.8 GHz) combined with a chemotherapy drug (doxorubicin) to see how radiation affects DNA repair. They found that while the radiation alone didn't damage DNA, it significantly interfered with the cells' ability to repair DNA damage caused by the chemotherapy drug. This suggests that cell phone radiation may impair the body's natural DNA repair mechanisms when cells are already stressed.

Reproductive HealthNo Effects Found

The lack of histological changes of CDMA cellular phone-based radio frequency on rat testis.

Lee HJ et al. · 2010

Researchers exposed male rats to cell phone radiation at 848.5 MHz for 12 weeks to study effects on sperm production and testicular health. They found no changes in sperm count, testicular tissue structure, or markers of cellular damage compared to unexposed rats. This suggests that exposure to this specific frequency and power level did not harm male reproductive function in rats.

Effects of electromagnetic fields emitted by mobile phones (GSM 900 and WCDMA/UMTS) on the macrostructure of sleep.

Danker-Hopfe H, Dorn H, Bahr A, Anderer P, Sauter C. · 2010

German researchers exposed 30 healthy men to cell phone radiation during sleep for multiple nights. While some minor statistical differences in sleep patterns occurred, these changes were minimal and didn't indicate meaningful sleep disruption, suggesting current safety limits don't harm sleep quality.

Reproductive HealthNo Effects Found

Lack of teratogenicity after combined exposure of pregnant mice to CDMA and WCDMA radiofrequency electromagnetic fields.

Lee HJ, Lee JS, Pack JK, Choi HD, Kim N, Kim SH, Lee YS. · 2009

Researchers exposed pregnant mice to cell phone signals (CDMA and WCDMA) at high levels throughout their entire pregnancy to test whether this radiation could cause birth defects. The study found no observable harmful effects on the developing fetuses, including no increased death rates, growth problems, or physical abnormalities. This suggests that exposure to these specific types of cell phone radiation during pregnancy may not cause obvious developmental problems in offspring.

Apoptosis is Induced by Radiofrequency Fields through the Caspase-Independent Mitochondrial Pathway in Cortical Neurons

Joubert, V., Bourthoumieu, S., Leveque, P. and Yardin, C. · 2008

Researchers exposed rat brain cells to cell phone-level radiofrequency radiation (900 MHz at 2 W/kg SAR) for 24 hours and found it triggered programmed cell death through a specific pathway involving mitochondria. The cell death occurred even when accounting for the slight heating effect of the radiation. This suggests that RF radiation can damage brain cells through non-thermal mechanisms at exposure levels similar to what cell phones produce.

Reproductive HealthNo Effects Found

In vitro effect of pulsed 900 MHz GSM radiation on mitochondrial membrane potential and motility of human spermatozoa.

Falzone N et al. · 2008

Researchers exposed human sperm samples to cell phone radiation at two different intensities to see if it affected sperm health and movement. They found no effects at the lower intensity (similar to normal phone use), but at the higher intensity, sperm swimming patterns became impaired over time. This suggests that stronger EMF exposures may harm male fertility, though typical phone use levels showed no immediate damage.

Effects of prenatal exposure to a 900 MHz electromagnetic field on the dentate gyrus of rats: a stereological and histopathological study.

Odaci E, Bas O, Kaplan S · 2008

Researchers exposed pregnant rats to cell phone-frequency electromagnetic fields daily during pregnancy. Their offspring showed significantly fewer brain cells in the hippocampus region responsible for learning and memory, suggesting EMF exposure during pregnancy may harm developing brain tissue.

Apoptosis is Induced by Radiofrequency Fields through the Caspase-Independent Mitochondrial Pathway in Cortical Neurons.

Joubert V, Bourthoumieu S, Leveque P, Yardin C. · 2008

French researchers exposed rat brain cells to cell phone-level radiofrequency radiation (900 MHz at 2 W/kg SAR) for 24 hours and found it triggered programmed cell death through a specific cellular pathway. The brain cells died at rates significantly higher than control groups, even when accounting for the slight temperature increase from the radiation. This suggests that RF radiation can damage neurons through mechanisms beyond just heating effects.

Cellular EffectsNo Effects Found

Acute radio frequency irradiation does not affect cell cycle, cellular migration, and invasion.

Lee JJ et al. · 2008

Researchers exposed mouse cells to cell phone-level radiofrequency radiation (849 MHz) at power levels of 2 or 10 watts per kilogram for up to three days and measured whether this affected cell division, movement, or invasion capabilities. They found no statistically significant changes in any of these cellular functions compared to unexposed cells. This suggests that short-term RF exposure at these power levels does not disrupt basic cellular processes related to growth and migration.

Effect of 1.8 GHz radiofrequency electromagnetic fields on gene expression of rat neurons

Zhang SZ, Yao GD, Lu DQ, Chiang H, Xu ZP. · 2008

Chinese researchers exposed rat brain neurons to 1.8 GHz radiofrequency radiation (the same frequency used in cell phones) at 2 W/kg for up to 24 hours. They found that 34 genes changed their expression patterns, including genes involved in brain cell structure and signaling. The changes were more pronounced with intermittent exposure than continuous exposure, suggesting that the pattern of EMF exposure matters for biological effects.

DNA & Genetic DamageNo Effects Found

Evaluation of HSP70 Expression and DNA Damage in Cells of a Human Trophoblast Cell Line Exposed to 1.8 GHz Amplitude-Modulated Radiofrequency Fields.

Valbonesi P et al. · 2008

Researchers exposed human placental cells to cell phone radiation (1.8 GHz GSM signals) for one hour at levels twice the current safety limit to see if it would trigger cellular stress responses or DNA damage. The radiation exposure produced no detectable effects on stress proteins or DNA integrity, unlike positive control treatments that did cause measurable damage. This suggests that short-term exposure to this type of cell phone radiation may not immediately harm these particular cells.

Immune SystemNo Effects Found

Effects of GSM-modulated radiofrequency electromagnetic fields on mouse bone marrow cells.

Prisco MG et al. · 2008

Italian researchers exposed mice to cell phone radiation (900 MHz GSM signals) for 4 weeks, then transplanted their bone marrow cells into radiation-damaged mice to test if the EMF exposure affected the immune system's ability to rebuild itself. The bone marrow cells from EMF-exposed mice performed just as well as unexposed cells in rescuing the damaged mice and rebuilding their immune systems. This suggests that moderate cell phone radiation exposure doesn't impair the bone marrow's critical immune-building functions.

DNA & Genetic DamageNo Effects Found101 citations

Genotoxic effects of exposure to radiofrequencyelectromagnetic fields (RF-EMF) in cultured mammalian cells are not independently reproducible.

Speit G, Schütz P, Hoffmann H. · 2007

German researchers attempted to replicate the controversial REFLEX study findings that showed cell phone radiation (1800 MHz) could damage DNA in human cells. Using identical equipment, cells, and exposure conditions, they found no DNA damage whatsoever. This directly contradicted the original REFLEX results that had suggested radiofrequency radiation at levels similar to cell phones could be genotoxic (DNA-damaging).

Brain & Nervous SystemNo Effects Found

Acute exposure to low-level CW and GSM-modulated 900 MHz radiofrequency does not affect Ba(2+) currents through voltage-gated calcium channels in rat cortical neurons.

Platano D et al. · 2007

Italian researchers exposed rat brain cells to 900 MHz radiofrequency radiation (the same frequency used by GSM cell phones) for short periods to see if it affected calcium channels, which are crucial for nerve cell communication. They found no changes in how calcium moved through these channels, even at radiation levels of 2 W/kg. This suggests that brief cell phone-level exposures may not immediately disrupt this particular aspect of brain cell function.

DNA & Genetic DamageNo Effects Found

Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in cultured mammalian cells are not independently reproducible.

Speit G, Schütz P, Hoffmann H. · 2007

German researchers exposed mammalian cells to radiofrequency radiation at cell phone levels (1800 MHz, SAR 2 W/kg) to test whether RF exposure causes DNA damage. Using two different cell lines and multiple DNA damage tests, they found no genetic damage from the radiation exposure. This study contradicted earlier findings from the REFLEX project that had reported DNA damage from similar RF exposures.

Cellular EffectsNo Effects Found

In Vitro Study of the Stress Response of Human Skin Cells to GSM-1800 Mobile Phone Signals Compared to UVB Radiation and Heat Shock.

Sanchez et al. · 2007

French researchers exposed human skin cells to GSM cell phone signals at the maximum allowed exposure level for 48 hours, looking for signs of cellular stress like those caused by heat or UV radiation. They found no evidence that the radiofrequency radiation caused stress responses or cell death, unlike the positive control treatments that clearly damaged cells. This suggests that cell phone radiation at current safety limits may not directly harm skin cells in laboratory conditions.

Brain & Nervous SystemNo Effects Found

Acute exposure to low-level CW and GSM-modulated 900 MHz radiofrequency does not affect Ba 2+ currents through voltage-gated calcium channels in rat cortical neurons.

Platano D et al. · 2007

Italian researchers exposed rat brain cells to 900 MHz radiofrequency radiation (the same frequency used by GSM cell phones) to see if it affected calcium channels, which are crucial for brain cell communication. After exposing the cells to radiation at 2 W/kg for short periods, they found no changes in how calcium moved through these channels. This suggests that brief exposure to cell phone-level radiation may not immediately disrupt this particular aspect of brain cell function.