8,700 Studies Reviewed. 87.0% 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

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.

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.

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.

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.

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.

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.

Studying gene expression profile of rat neuron exposed to 1800MHz radiofrequency electromagnetic fields with cDNA microassay.

Zhao R, Zhang S, Xu Z, Ju L, Lu D, Yao G. · 2007

Chinese researchers exposed rat brain neurons to cell phone-frequency radiation (1800 MHz) for 24 hours at power levels similar to heavy phone use. They found that 34 genes changed their activity levels, affecting how neurons function in areas like cell structure, communication, and metabolism. This demonstrates that radiofrequency radiation can alter the fundamental genetic programming of brain cells.

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.

SAR in the mother and foetus for RF plane wave irradiation.

Dimbylow P. · 2007

Researchers created detailed computer models of pregnant women at different stages of pregnancy (8 to 38 weeks) to measure how radiofrequency radiation is absorbed by both the mother and developing baby. They found that current safety guidelines appear to provide adequate protection for the fetus, with radiation absorption levels staying within established limits across all pregnancy stages tested.

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.

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).

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.

Oxidative StressNo Effects Found

Hsp70 expression and free radical release after exposure to non-thermal radio-frequency electromagnetic fields and ultrafine particles in human Mono Mac 6 cells.

Simkó M et al. · 2006

Researchers exposed human immune cells to radiofrequency radiation at cell phone levels (2 W/kg SAR) and ultrafine air pollution particles to see if they would trigger cellular stress responses. They found that while the particles caused significant oxidative stress and free radical production, the RF radiation alone showed no measurable effects on stress proteins or free radical levels, even when combined with the particles.

Cellular EffectsNo Effects Found

Human skin cell stress response to GSM-900 mobile phone signals. In vitro study on isolated primary cells and reconstructed epidermis

Sanchez S et al. · 2006

Researchers exposed human skin cells to cell phone radiation at the legal safety limit (2 W/kg SAR) for 48 hours to see if it triggered cellular stress responses. They found minimal changes - no cell death or tissue damage, with only slight increases in one stress protein in some cell types. The results suggest that skin cells can adapt to this level of radiofrequency exposure without harmful effects.

Immune SystemNo Effects Found

Effects of GSM-modulated radiofrequency electromagnetic fields on B-cell peripheral differentiation and antibody production.

Nasta F et al. · 2006

Researchers exposed mice to cell phone radiation (900 MHz GSM signals) for 2 hours daily over 4 weeks to test whether it affects immune system function, specifically B-cells that produce antibodies to fight infections. They found no changes in B-cell development, antibody production, or immune responses compared to unexposed mice. This suggests that this level of cell phone radiation exposure doesn't impair the immune system's ability to protect against disease.

Oxidative StressNo Effects Found107 citations

ROS release and Hsp70 expression after exposure to 1,800 MHz radiofrequency electromagnetic fields in primary human monocytes and lymphocytes.

Lantow M, Lupke M, Frahm J, Mattsson MO, Kuster N, Simko M. · 2006

Researchers exposed human immune cells (monocytes and lymphocytes) to cell phone radiation at 1,800 MHz for 30-45 minutes to see if it would trigger oxidative stress or cellular stress responses. They found no meaningful biological effects from the RF exposure, with any statistical differences appearing to be due to measurement variations rather than actual cellular damage.

.[Effect of 1.8 GHz radiofrequency electromagnetic fields on the expression of microtubule associated protein 2 in rat neurons]

Zhao R, Zhang SZ, Yao GD, Lu DQ, Jiang H, Xu ZP · 2006

Researchers exposed newborn rat brain cells to 1.8 GHz radiofrequency radiation (similar to cell phone frequencies) at 2 watts per kilogram for 24 hours and found that 34 out of 1,200 genes changed their expression levels. Most notably, a gene called MAP2, which helps maintain the structural framework of brain cells, became significantly more active after radiation exposure.

Cellular EffectsNo Effects Found

Comparative study of cell cycle kinetics and induction of apoptosis or necrosis after exposure of human mono mac 6 cells to radiofrequency radiation.

Lantow M, Viergutz T, Weiss DG, Simko M. · 2006

German researchers exposed human immune cells (Mono Mac 6 cells) to cell phone radiation at 1,800 MHz for 12 hours to see if it would cause cell death or disrupt normal cell division cycles. They found no statistically significant effects on cell death, cell division, or DNA synthesis compared to unexposed control cells. This suggests that at the tested exposure level, cell phone-type radiation did not harm these particular immune cells in laboratory conditions.

DNA & Genetic DamageNo Effects Found

[Global gene response to GSM 1800 MHz radiofrequency electromagnetic field in MCF-7 cells.]

Wang LL, Chen GD, Lu DQ, Chiang H, Xu ZP. · 2006

Researchers exposed breast cancer cells (MCF-7) to cell phone radiation at 1800 MHz for 24 hours to see if it would change gene activity. They found essentially no meaningful changes in gene expression, even when using exposure levels higher than typical cell phone use. The study suggests that this type of radiation may not significantly alter how genes function in these particular cells.

Cellular EffectsNo Effects Found

Radiofrequency radiation does not induce stress response in human T-lymphocytes and rat primary astrocytes.

Lee JS, Huang TQ, Kim TH, Kim JY, Kim HJ, Pack JK, Seo JS. · 2006

Researchers exposed human immune cells and rat brain cells to cell phone-level radiofrequency radiation (1763 MHz) at power levels of 2 and 20 W/kg for up to one hour while carefully controlling temperature. They found no activation of cellular stress responses, including heat shock proteins and stress-signaling pathways that typically activate when cells are damaged. This suggests that RF radiation at these levels does not trigger the cellular alarm systems that respond to harmful stressors.

Brain & Nervous SystemNo Effects Found

Microwave exposure of neuronal cells in vitro: Study of apoptosis.

Joubert V et al. · 2006

French researchers exposed human brain cells to cell phone radiation at 900 MHz for 24 hours to see if it would trigger cell death (apoptosis). They tested two exposure levels - one mimicking typical phone use and another eight times higher. The study found no increase in brain cell death at either exposure level, suggesting that 24-hour exposure to cell phone radiation does not kill these particular brain cells.

Immune SystemNo Effects Found

Hsp70 expression and free radical release after exposure to non-thermal radio-frequency electromagnetic fields and ultrafine particles in human Mono Mac 6 cells.

Simko M et al. · 2006

German researchers exposed human immune cells (monocytes) to radiofrequency radiation at 2 W/kg SAR - similar to cell phone levels - while also testing exposure to ultrafine air pollution particles. They measured two key stress indicators: free radical production and heat shock proteins. While the air pollution particles triggered significant stress responses, the RF radiation produced no measurable effects on either stress marker, even when combined with the particles.