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

Glial markers and emotional memory in rats following acute cerebral radiofrequency exposures.

Barthélémy A et al. · 2016

Researchers exposed rats to radiofrequency radiation for 15 minutes at different intensities and measured brain inflammation and memory function. They found that even low-level exposure (1.5 W/kg) caused significant brain inflammation, while higher exposure (6 W/kg) impaired long-term memory and increased inflammation in multiple brain regions. This study provides direct evidence that brief RF exposure can trigger brain inflammation and memory problems in living animals.

Effect of Radiofrequency Radiation on Human Hematopoietic Stem Cells.

Gläser K et al. · 2016

German researchers exposed human blood stem cells (the cells that create all blood cells in your body) to cell phone radiation at three different frequencies for up to 66 hours. They tested multiple biological endpoints including DNA damage, cell death, and oxidative stress. Surprisingly, they found that GSM radiation actually caused a small decrease in DNA damage compared to unexposed cells, while showing no other significant effects.

8-oxoG DNA Glycosylase-1 Inhibition Sensitizes Neuro-2a Cells to Oxidative DNA Base Damage Induced by 900 MHz Radiofrequency Electromagnetic Radiation.

Wang X et al. · 2015

Researchers exposed mouse brain cells to 900 MHz cell phone radiation for 24 hours and found it caused DNA damage through oxidative stress. The damage occurred at radiation levels as low as 1-2 watts per kilogram, which is within the range of typical cell phone use. When the cells' natural DNA repair mechanisms were disabled, even lower radiation levels caused genetic damage.

Cancer & Tumors109 citations

Tumor promotion by exposure to radiofrequency electromagnetic fields below exposure limits for humans.

Lerchl A et al. · 2015

German researchers exposed mice to radiofrequency radiation at levels similar to cell phones and found significantly higher numbers of lung, liver, and lymph node tumors compared to unexposed animals. The tumor-promoting effects occurred at very low exposure levels - well below current safety limits for mobile phone users. This replication study confirms earlier findings that RF radiation may accelerate tumor growth even when it doesn't directly cause cancer.

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 retinal tissue to cell phone radiation at various power levels (including some 10 times higher than typical phone use) to see if it affected eye cells that help process vision. They found no changes in how these retinal ganglion cells responded to light, even at the highest radiation levels tested. The study was carefully controlled to eliminate temperature effects, focusing only on potential non-thermal impacts of RF radiation on eye function.

Brain & Nervous SystemNo Effects Found

In Situ Expression of Heat-Shock Proteins and 3-Nitrotyrosine in Brains of Young Rats Exposed to a WiFi Signal In Utero and In Early Life

Aït-Aïssa S et al. · 2013

French researchers exposed pregnant rats and their newborns to WiFi signals (2450 MHz) for 2 hours daily during pregnancy and early life, then examined brain tissue for signs of stress and damage. They found no differences in stress markers or heat-shock proteins between exposed and unexposed rats at any of the tested exposure levels. The study suggests that WiFi exposure during critical developmental periods may not cause detectable brain damage in rats.

Brain & Nervous SystemNo Effects Found

In Situ Expression of Heat-Shock Proteins and 3-Nitrotyrosine in Brains of Young Rats Exposed to a WiFi Signal In Utero and In Early Life.

Aït-Aïssa S et al. · 2013

French researchers exposed pregnant rats and their offspring to WiFi signals (2.4 GHz) from pregnancy through 5 weeks after birth, then examined their brains for signs of cellular stress and damage. They found no differences in stress markers between WiFi-exposed and unexposed rat pups, even at exposure levels up to 4 W/kg. The study suggests that WiFi exposure during critical developmental periods may not cause detectable brain damage in young rats.

In utero and early-life exposure of rats to a Wi-Fi signal: screening of immune markers in sera and gestational outcome.

Aït-Aïssa S et al. · 2012

French researchers exposed pregnant rats and their newborn pups to Wi-Fi signals (2.45 GHz) for two hours daily during pregnancy and early life, then tested the young rats' blood for immune system markers and signs of developmental problems. They found no changes in immune responses or reproductive development at any exposure level tested, including levels much higher than typical human exposure to Wi-Fi.

Brain & Nervous SystemNo Effects Found

Electromagnetic Field Effect or Simply Stress? Effects of UMTS Exposure on Hippocampal Longterm Plasticity in the Context of Procedure Related Hormone Release

Prochnow N et al. · 2011

Researchers exposed rats to UMTS cell phone signals at different power levels to study effects on memory formation in the brain. They found no impact on memory-related brain activity at 2 W/kg (similar to phone use), but significant disruption at 10 W/kg (five times higher than typical exposure). The study suggests current cell phone radiation levels may not harm memory processes, but much higher exposures could be problematic.

Brain & Nervous SystemNo Effects Found

Effects of head-only exposure of rats to GSM-900 on blood-brain barrier permeability and neuronal degeneration.

de Gannes FP et al. · 2009

Researchers exposed rats to cell phone radiation (GSM-900) for 2 hours and checked for brain damage 14 and 50 days later. They found no evidence of blood-brain barrier leakage or neuronal death at exposure levels ranging from very low to high. This study directly contradicted earlier research that claimed similar exposures caused significant brain damage.

Cellular EffectsNo Effects Found

Evaluating the biological effects of intermittent 1.9 GHz pulse-modulated radiofrequency fields in a series of human-derived cell lines.

Chauhan V et al. · 2007

Canadian government researchers exposed three types of human cells to 1.9 GHz radiofrequency radiation (similar to cell phone signals) for 6 hours at power levels up to 10 W/kg. They measured multiple indicators of cellular stress including cell death, DNA damage, immune responses, and cell cycle disruption. The study found no detectable biological effects from the RF exposure at any power level tested.

Radio FrequencyNo Effects Found

Role of blood flow on RF exposure induced skin temperature elevations in rabbit ears.

Jia F, Ushiyama A, Masuda H, Lawlor GF, Ohkubo C. · 2007

Researchers exposed rabbit ears to radiofrequency radiation at different power levels for 20 minutes, measuring temperature changes with and without blood flow. They found that normal blood circulation effectively prevented heating at exposure levels matching current safety limits (2 W/kg for the public, 10 W/kg for workers), but when blood flow was blocked, even the lowest exposure level caused temperature increases. This demonstrates that living tissue's natural cooling mechanisms are crucial for protecting against RF heating effects.

Effects of 900 MHz GSM Wireless Communication Signals on DMBA-Induced Mammary Tumors in Rats.

Yu D, Shen Y, Kuster N, Fu Y, Chiang H. · 2006

Researchers exposed 500 female rats to 900 MHz cell phone radiation (the same frequency used by GSM phones) for 4 hours daily over 26 weeks after giving them a cancer-causing chemical. While the study found no statistically significant increase in mammary tumors from RF exposure, there was a concerning trend toward higher cancer rates in rats exposed to the highest radiation levels, particularly during weeks 15-26.

[Effect of acute exposure to microwave from mobile phone on DNA damage and repair of cultured human lens epithelial cells in vitro.]

Sun LX, Yao K, He JL, Lu DQ, Wang KJ, Li HW. · 2006

Researchers exposed human eye lens cells to cell phone radiation for 2 hours at different power levels to see if it damages DNA. They found that lower exposure levels (up to 3 W/kg) caused temporary DNA breaks that the cells could repair, but higher exposure (4 W/kg) caused permanent DNA damage that cells couldn't fix.

Response, thermal regulatory threshold and thermal breakdown threshold of restrained RF-exposed mice at 905 MHz.

Ebert S et al. · 2005

Researchers exposed mice to 905 MHz radiofrequency radiation at various power levels to determine when their bodies could no longer regulate temperature. They found that mice began struggling to maintain normal body temperature at radiation levels between 2-5 W/kg, and completely lost temperature control around 6-10 W/kg during 2-hour exposures.

DNA & Genetic DamageNo Effects Found

Effects of 1-week and 6-week exposure to GSM/DCS radiofrequency radiation on micronucleus formation in B6C3F1 Mice.

Gorlitz BD et al. · 2005

Researchers exposed mice to cell phone radiation (GSM and DCS frequencies) for 2 hours daily over 1 and 6 weeks to test whether it causes DNA damage in blood cells and other tissues. They found no increase in micronuclei (tiny fragments that indicate genetic damage) in any of the cell types examined, even at radiation levels up to 33.2 mW/g. This suggests that cell phone-type radiation at these exposure levels does not cause detectable genetic damage in mice.

Brain & Nervous SystemNo Effects Found

Lack of effects of 1439 MHz electromagnetic near field exposure on the blood-brain barrier in immature and young rats.

Kuribayashi M et al. · 2005

Researchers exposed young and developing rats to cell phone-frequency radiation (1439 MHz) for 90 minutes daily to see if it damaged the blood-brain barrier, which protects the brain from harmful substances. Even at high exposure levels (up to 6 W/kg), they found no changes in barrier function or protective proteins after 1-2 weeks of exposure. This suggests that this type of radiofrequency radiation may not compromise the brain's natural protective barrier in young animals.

DNA & Genetic DamageNo Effects Found

No Evidence for Genotoxic Effects from 24 h Exposure of Human Leukocytes to 1.9 GHz Radiofrequency Fields.

McNamee et al. · 2003

Canadian researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation for 24 hours at levels ranging from 0 to 10 W/kg (a range that includes typical cell phone exposure levels). They found no evidence of DNA damage or genetic harm using two different laboratory tests that measure cellular damage. This study suggests that extended RF exposure at these levels does not cause detectable genetic damage to human blood cells under controlled laboratory conditions.

DNA & Genetic DamageNo Effects Found

DNA Damage in human leukocytes after acute in vitro exposure to a 1.9 GHz pulse-modulated radiofrequency field.

McNamee JP et al. · 2002

Canadian researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation (similar to cell phone signals) for 2 hours at various power levels up to 10 W/kg. They found no evidence of DNA damage using two different laboratory tests that measure genetic harm. This suggests that short-term exposure to this type of RF radiation at these levels does not break DNA strands in immune cells.

DNA & Genetic DamageNo Effects Found

DNA damage and micronucleus induction in human leukocytes after acute in vitro exposure to a 1.9 GHz continuous-wave radiofrequency field.

McNamee JP et al. · 2002

Researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation for 2 hours at various power levels to test whether RF exposure causes DNA damage or creates abnormal cell structures called micronuclei. They found no evidence of genetic damage at any exposure level tested, including levels 100 times higher than typical cell phone emissions.

DNA & Genetic DamageNo Effects Found

DNA Damage in human leukocytes after acute in vitro exposure to a 1.9 GHz pulse-modulated radiofrequency field.

McNamee JP et al. · 2002

Canadian researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation (similar to cell phone frequencies) for 2 hours at various power levels up to 10 W/kg. They found no DNA damage in the cells compared to unexposed controls, using two different laboratory tests to detect genetic harm. This study suggests that short-term RF exposure at these levels does not cause immediate DNA breaks in immune cells.

DNA & Genetic DamageNo Effects Found

Cytogenetic effects of 900 MHz (GSM) microwaves on human lymphocytes

Maes A, Collier M, Verschaeve L · 2001

Researchers exposed human immune cells (lymphocytes) to 900 MHz cell phone radiation at various power levels to see if it caused DNA damage or made cells more vulnerable to other harmful substances. They found no evidence that this type of radiofrequency radiation damaged chromosomes or increased genetic damage when combined with known cancer-causing chemicals or X-rays.

Brain & Nervous SystemNo Effects Found

Effects of high peak power microwaves on the retina of the rhesus monkey.

Lu ST et al. · 2000

Researchers exposed rhesus monkeys to high-power microwave radiation (1.25 GHz) for 4 hours daily over 3 weeks to study effects on the retina (the light-sensitive tissue at the back of the eye). At moderate exposure levels (4.3 W/kg), they found no changes, but at higher levels (8.4-20.2 W/kg), some monkeys showed enhanced electrical responses in cone cells that detect color vision, though no actual damage occurred. The researchers concluded that retinal injury is very unlikely at 4 W/kg and that any changes at higher levels would likely be reversible.