6,486 Studies Reviewed. 85.2% of Original Studies 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:

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

Showing 898 studies with measured sar (specific absorption rate) exposure

Immune SystemNo Effects Found

Molecular responses of Jurkat T-cells to 1763 MHz radiofrequency radiation.

Huang TQ, Lee MS, Oh E, Zhang BT, Seo JS, Park WY. · 2008

They assessed cell proliferation, cell cycle progression, DNA damage, and gene expression. RF exposure did not significantly change cell numbers, cell cycle distribution, or DNA damage levels. Genome-wide analysis found no genes changed more than two-fold, but ten genes changed 1.3- to 1.8-fold, including down-regulation of CXCR3 and IL1R2.

Behavioral teratologic studies using microwave radiation: is there an increased risk from exposure to cellular phones and microwave ovens?

Jensh RP · 1997

This review examined whether chronic prenatal microwave exposure in rats caused adverse effects at birth or alterations in offspring development and growth. Pregnant rats were exposed throughout pregnancy to continuous wave 915 MHz, 2450 MHz, or 6000 MHz radiation at power density levels of 10, 20, or 35 mW/cm2, respectively. Animals exposed to 915 MHz did not exhibit any consistent significant alterations in any of the parameters measured. Offspring exposed to 6000 MHz showed an initial slight but significant retardation in term weight, delayed eye opening, lower weekly weights that recovered by the fifth week, and changes in water T-maze and open field performance.

Effects of 2.45-GHz microwave radiation and phorbol ester 12-O-tetradecanoylphorbol-13-acetate on dimethylhydrazine-induced colon cancer in mice.

Wu RY, Chiang H, Shao BJ, Li NG, Fu YD · 1994

The study used 115 Balb/c mice that were 4 weeks old, divided into control, DMH, DMH plus microwave, and DMH plus TPA groups. The microwave exposure was 2.45 GHz radiation at 10 mW/cm2 delivered dorsally in an anechoic chamber. Radiation was administered 3 hours daily, 6 days per week for 5 months, and DMH was injected once per week. Tumor incidence did not differ significantly among the three DMH treatment groups. Group D had more tumors, larger tumors, and more protuberant and infiltrative tumor types than groups B and C, and groups B and C did not differ.

Local exposure of the rat cortex to radiofrequency electromagnetic fields increases local cerebral blood flow along with temperature

Masuda H et al. · 2011

The study aimed to detect reproducible responses to local radiofrequency exposure in the parietal cortex of anesthetized rats and to determine their dependence on exposure intensity. The target cortex tissue was locally exposed to 2-GHz RF using a figure-eight loop antenna at averaged specific absorption rates of 10.5, 40.3, 130, and 263 W/kg. All measured parameters except calf hypodermis temperature increased significantly in exposed animals compared with sham-exposed ones during 18-min exposures. The local cerebral blood flow elevation seemed to be driven by the rise in target temperature, but not by rectal temperature, in the early part of RF exposure or at low-intensity RF exposure.

Local exposure of the rat cortex to radiofrequency electromagnetic fields increases local cerebral blood flow along with temperature.

Masuda H et al. · 2011

Japanese researchers exposed rat brain tissue to 2-GHz radiofrequency radiation at various intensities and measured changes in blood flow and temperature. They found that RF exposure significantly increased both local brain blood flow and temperature in a dose-dependent manner - the higher the exposure, the greater the response. This demonstrates that RF radiation directly affects brain physiology by triggering the body's natural response to increased heat in brain tissue.

DNA & Genetic DamageNo Effects Found

Micronuclei in the peripheral blood and bone marrow cells of rats exposed to 2450 MHz radiofrequency radiation.

Vijayalaxmi et al. · 2001

Eight adult male Sprague-Dawley rats were exposed to 2450 MHz RFR in circularly polarized waveguides, and eight sham-exposed rats were kept in similar waveguides without RFR transmission. Four rats treated with mitomycin-C served as positive controls, and all rats were necropsied 24h after exposure to examine peripheral blood and bone marrow smears for micronuclei in polychromatic erythrocytes. The incidence of micronuclei per 2000 polychromatic erythrocytes was not significantly different between RFR-exposed and sham-exposed rats.

CardiovascularNo Effects Found

Cardiovascular and thermal effects of microwave irradiation at 1 and/or 10 GHz in anesthetized rats.

Jauchem JR, Ryan KL, Freidagger MR · 2000

Ketamine-anesthetized male Sprague-Dawley rats were exposed to 1 GHz, 10 GHz, or combined 1 and 10 GHz microwaves at a whole-body specific absorption rate of 12 W/kg. Exposures were conducted in E and H orientations under far-field conditions until lethal temperatures were reached. Survival time was shortest at 1 GHz, intermediate for combined frequencies, and longest at 10 GHz, with most differences statistically significant. Temperature values at most sites for combined exposure fell between those of the single-frequency groups. Arterial blood pressure initially increased then decreased until death, heart rate increased throughout, and patterns were similar across all groups.

Effects of continuous and pulsed 2450-MHz radiation on spontaneous lymphoblastoid transformation of human lymphocytes in vitro.

Czerska EM, Elson EC, Davis CC, Swicord ML, Czerski P · 1992

Researchers exposed human lymphocytes in vitro for 5 days to continuous-wave (CW) or pulsed-wave (PW) 2450-MHz radiation at non-heating and heating levels, with actual average SARs ranging to 12.3 W/kg. At non-heating levels, CW exposure did not affect spontaneous lymphoblastoid transformation, but PW exposure enhanced it significantly (P less than .002). At heating levels, PW exposure enhanced transformation to a greater extent than either conventional heating or CW heating, a finding significant at the .02 level.

Microwaves induce an increase in the frequency of complement receptor-bearing lymphoid spleen cells in mice

Unknown authors

This mouse study investigated how microwave radiation exposure affects immune system cells in the spleen, specifically looking at lymphoid cells that carry complement receptors. The researchers found that microwave exposure increased the frequency of these immune cells, suggesting that microwave radiation can alter immune system function at the cellular level.

Brain & Nervous SystemNo Effects Found

Characterization of biological effect of 1763 MHz radiofrequency exposure on auditory hair cells.

Huang TQ et al. · 2008

Researchers exposed HEI-OC1 immortalized mouse auditory hair cells to 1763 MHz RF at 20 W/kg SAR in a CDMA chamber for 24 and 48 hours. They assessed cell cycle, DNA damage, heat shock protein expression, MAPK phosphorylation, and gene expression, finding no changes in cell cycle, DNA damage, HSP expression, or MAPK phosphorylation. Microarray analysis showed only 29 genes (0.09% of total) changed more than 1.5-fold after exposure.

Ouabain inhibition of kidney ATPase is altered by 9.14 GHz radiation.

Brown HD, Chattopadhyay SK · 1991

Researchers studied how 9.14 GHz continuous-wave microwave radiation affected ouabain inhibition of Na+/K+-ATPase from dog kidney. Exposure for 5 minutes to 9.14 GHz radiation at an estimated SAR of 20 W/kg was applied at several stabilized temperatures between 7.0 and 43.8 °C. The efficacy of ouabain as an inhibitor of ATPase activity was severely diminished by the microwave field, and at 24.9 °C a 23% decrease in activity occurred.

Neuroprotective effects of dietary supplement Kang-fu-ling against high-power microwave through antioxidant action

Hu S et al. · 2014

Researchers exposed male Wistar rats to high-power microwave at 30 mW cm−2 for 15 minutes, then administered the dietary supplement KFL orally once daily for 14 days. KFL reversed high-power microwave-induced memory loss and histopathological changes in the hippocampus of rats. KFL also displayed a protective effect against high-power microwave-induced oxidative stress and activated the Nrf2 signaling pathway and its target genes in the hippocampus.

Naltrexone-sensitive analgesia following exposure of mice to 2450-MHz radiofrequency radiation

Maillefer RH, Quock RM · 1992

Male Swiss Webster mice were exposed to 10, 15, and 20 mW/cm2 RFR at 2450 MHz for 10 minutes at SARs of 23.7, 34.6, and 45.5 W/kg, then tested in the abdominal constriction paradigm. Confinement alone did not appreciably alter body temperature but appeared to induce stress-associated analgesia that was not blocked by naltrexone. RFR exposure raised body temperature and further increased analgesia in an SAR-dependent manner. The high SAR-induced analgesia was blocked by naltrexone, but the hyperthermia was not.

Effect of isothermal radiofrequency radiation on cytolytic T lymphocytes.

Cleary, SF, Du, Z, Cao, G, Liu, LM, McCrady, C · 1996

Researchers investigated the effects of RF radiation exposure on interleukin 2 (IL-2) -dependent proliferation of cytolytic T lymphocytes (CTLL-2). At specific absorption rates greater than 25 W/kg, exposure produced a consistent, statistically significant reduction in CTLL-2 proliferation, especially at low IL-2 concentrations. At lower SARs, 2450 MHz exposure increased CTLL-2 proliferation immediately after exposure but reduced 24 h postexposure proliferation. The researchers found significant qualitative and quantitative differences between the effects of temperature elevation and RF radiation.

Amino acid concentrations in hypothalamic and caudate nuclei during microwave-induced thermal stress: analysis by microdialysis.

Mason PA et al. · 1997

Researchers measured extracellular amino acid concentrations in the hypothalamus and caudate nucleus of rats using in vivo microdialysis before and during exposure to RFR. Rats were exposed to 5.02 GHz radiation (10 microseconds pulse width, 1000 pulses/s) for 40 minutes while brain temperatures were maintained at approximately 41.2 and 41.7 degrees C. Aspartic acid, serine, and glycine concentrations increased significantly in both regions during exposure. Glutamic acid and glutamine changes were not statistically significant.

Brain & Nervous SystemNo Effects Found

Using the nonlinear control of anesthesia-induced hypersensitivity of EEG at burst suppression level to test the effects of radiofrequency radiation on brain function.

Lipping T et al. · 2009

Researchers exposed eleven anesthetized pigs to mobile phone radiation at 890 MHz to test whether radiofrequency signals could trigger brain activity changes in a highly sensitive state. They found no correlation between RF exposure and brain wave patterns, though the animals experienced significant temperature increases (1.6°C) and elevated heart rates during the 10-minute exposures. This suggests that while RF radiation can cause heating effects, it may not directly stimulate brain activity even under conditions of heightened neural sensitivity.

Brain & Nervous SystemNo Effects Found

Using the nonlinear control of anaesthesia-induced hypersensitivity of EEG at burst suppression level to test the effects of radiofrequency radiation on brain function.

Lipping T et al. · 2009

Eleven pigs were anaesthetized to a burst-suppression EEG level and exposed to a GSM mobile phone signal at 890 MHz. In phase I, EMF stimulation was randomly switched on and off to study the relation between EEG bursts and EMF onsets and endpoints. In phase II, continuous RF stimulation at 31 W/kg was applied for 10 minutes while ECG, EEG, and subcutaneous temperature were recorded. No correlation between exposure and EEG burst occurrences was observed in phase I, and no significant EEG changes were found in phase II. Subcutaneous temperature increased by 1.6°C and heart rate by 14.2 bpm on average during the 10-minute exposure periods.

DNA & Genetic DamageNo Effects Found

Absence of a synergistic effect between moderate-power radio-frequency electromagnetic radiation and adriamycin on cell-cycle progression and sister-chromatid exchange.

Ciaravino V, Meltz ML, Erwin DN · 1991

Researchers exposed Chinese hamster ovary cells to adriamycin and pulsed RFR at 2,450 MHz and 33.8 W/Kg for 2 h. The maximal temperature in the tissue-culture medium was 39.7 +/- 0.2 degrees C. The experiments were controlled for chemical and RFR exposures as well as for temperature. Verified statistically, the data indicate that the RFR did not affect changes in cell progression caused by adriamycin and did not change the number of sister chromatid exchanges induced by adriamycin.