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.
Based on Building Biology Institute guidelines (W/kg (watts per kilogram)):
See where common exposures fall on the scale:
Showing 871 studies with measured sar (specific absorption rate) exposure
Erdem Koç G et al. · 2016
Pregnant rats exposed to cell phone radiation (900 MHz) for one hour daily had offspring with fewer brain cells in the hippocampus, the memory center. Melatonin and omega-3 supplements during pregnancy prevented this brain damage, suggesting potential protective strategies for human prenatal development.
Nakatani-Enomoto S et al. · 2016
Researchers exposed human sperm samples to cell phone-like radiation (1950 MHz) for one hour at two different power levels to see if it affected sperm movement or caused DNA damage. They found no significant changes in sperm motility, movement patterns, or DNA damage markers compared to unexposed samples. This study suggests that short-term exposure to this type of radiation may not immediately harm sperm function under controlled laboratory conditions.
Masuda H et al. · 2015
Researchers exposed rat brain tissue to cell phone-level radiofrequency radiation (1439 MHz) for 50 minutes. They found no changes in blood vessel size, blood flow speed, or brain inflammation during exposure, suggesting this radiation level doesn't immediately disrupt brain circulation.
Kumar G, McIntosh RL, Anderson V, McKenzie RJ, Wood AW. · 2015
Researchers exposed rat bone marrow to cell phone-type radiation at 900 MHz and 1800 MHz frequencies to test for DNA damage and changes in blood cell production. They found no significant effects on genetic damage or cell growth at radiation levels of 2-2.5 watts per kilogram, which are similar to current safety limits. This study suggests that short-term exposure to these specific radiation levels may not cause immediate DNA damage in blood-forming cells.
Zuo WQ, Hu YJ, Yang Y, Zhao XY, Zhang YY, Kong W, Kong WJ. · 2015
Researchers exposed rat auditory nerve cells to mobile phone radiation at 2-4 W/kg levels, with and without mild inflammation. Radiation alone caused no damage, but significantly harmed pre-inflamed cells, suggesting EMF exposure may be more dangerous when your body is already fighting inflammation.
Lustenberger et al. · 2015
Researchers exposed 20 young men to cell phone-level radiation (900 MHz) for 30 minutes before sleep on two separate occasions, then monitored their brain waves throughout the night. They found that RF exposure increased delta-theta brain wave activity in the frontal-central regions during deep sleep, but these effects varied significantly between individuals and weren't consistent when the same person was tested twice.
Lustenberger et al. · 2015
Swiss researchers exposed 20 young men to cell phone-level radiation (900 MHz at 2 watts per kilogram) for 30 minutes before sleep on two separate nights, then monitored their brain activity throughout the night using EEG. While they found some increases in certain brain wave patterns during deep sleep, these effects were inconsistent - they didn't reliably occur in the same individuals across both exposure sessions. This suggests that if cell phone radiation affects sleep brain activity, the response varies unpredictably between people and even within the same person on different nights.
Zhang Y, Li Z, Gao Y, Zhang C. · 2015
Researchers exposed pregnant mice to microwave radiation throughout pregnancy and tested their offspring's behavior. They found that prenatal microwave exposure increased anxiety-like behaviors in both male and female offspring, but only impaired learning and memory in males. This study provides the first evidence that microwave radiation can cause gender-specific developmental effects on the brain.
Kumar G, McIntosh RL, Anderson V, McKenzie RJ, Wood AW. · 2015
Researchers exposed rat bone marrow to mobile phone radiation at 900 and 1800 MHz frequencies to test for genetic damage and effects on blood cell production. They tested both continuous and pulsed signals at power levels ranging from 2 to 12.4 watts per kilogram. The study found no significant changes in cell growth or DNA damage in the bone marrow cells after exposure.
Hou Q, Wang M, Wu S, Ma X, An G, Liu H, Xie F · 2015
Scientists exposed mouse cells to 1800 MHz cell phone radiation at typical phone exposure levels and found it caused oxidative stress and increased cell death within one hour. This shows cell phone radiation can damage cells even at government-approved levels.
Danker-Hopfe H et al. · 2015
Researchers exposed 30 healthy men to cell phone radiation during sleep and found 90% showed altered sleep patterns. The most consistent change was increased REM (dream) sleep in one-third of participants, suggesting cell phone signals can affect brain activity during sleep.
Kang KA et al. · 2014
Researchers exposed neuronal brain cells to combined cell phone radiation (CDMA and WCDMA signals) for 2 hours to measure whether this caused oxidative stress, a type of cellular damage linked to various health problems. The study found no increase in reactive oxygen species (cellular damage markers) in any of the three types of brain cells tested, even when combined with known oxidative stress agents.
Lu Y et al. · 2014
Researchers exposed brain cells to 1,800 MHz cell phone radiation and found it triggered inflammation in both microglia and astrocytes, but through different biological pathways. The study identified how radiofrequency exposure activates specific proteins that release inflammatory chemicals, potentially explaining brain inflammation from cell phone use.
Hou Q, Wang M, Wu S, Ma X, An G, Liu H, Xie F. · 2014
Researchers exposed mouse cells to 1800-MHz cell phone radiation at levels similar to what phones emit during calls (2 W/kg SAR). They found that even intermittent exposure for just one hour significantly increased harmful reactive oxygen species and caused more cells to die through a process called apoptosis. This demonstrates that cell phone radiation can trigger cellular stress and damage at exposure levels considered safe by current regulations.
Valbonesi P, Franzellitti S, Bersani F, Contin A, Fabbri E. · 2014
Italian scientists exposed nerve cells to cell phone radiation at twice safety limits for 24 hours. Only specific GSM signal patterns triggered cellular stress responses, while other signal types had no effect. This suggests the way phone signals are structured affects biological impact.
Koyama S et al. · 2014
Japanese researchers exposed immune cells called neutrophils to 2.45-GHz radiofrequency radiation (the same frequency used in WiFi and microwave ovens) at levels up to 10 W/kg for up to 24 hours. They found no significant effects on the cells' ability to migrate toward threats or engulf harmful particles - two critical immune functions. This suggests that RF exposure at current safety limits may not impair these specific immune responses.
Kim HS et al. · 2014
Korean researchers exposed rats to cell phone radiation at levels similar to what phones emit (2 W/kg SAR) for up to 8 hours daily over two weeks, then examined whether this affected the brain's ability to generate new neurons. They found no significant changes in new brain cell formation in two key brain regions compared to unexposed rats, suggesting that short-term CDMA cell phone radiation exposure doesn't impair neurogenesis in healthy adult brains.
Ozgur E, Guler G, Kismali G, Seyhan N · 2014
Researchers exposed liver cancer cells to mobile phone radiation at levels typical of phone use (2 W/kg SAR) for up to 4 hours. The radiation decreased cell survival and caused DNA damage, with 1,800-MHz frequencies proving more harmful than 900-MHz. This suggests that the radiofrequency radiation from mobile phones can directly damage cells at exposure levels considered safe by current regulations.
Kang KA et al. · 2013
Researchers exposed neuronal brain cells to combined cell phone radiation (CDMA and WCDMA signals) for 2 hours to see if it would increase reactive oxygen species (ROS), which are harmful molecules that can damage cells. The study found no increase in ROS levels from the radiation exposure, even when combined with chemicals known to cause oxidative stress. This suggests the specific radiation levels tested did not trigger cellular damage in these lab-grown brain cells.
Zhijian C et al. · 2013
Researchers exposed human immune cells to cell phone radiation (1.8 GHz) for 24 hours. They found significant changes in 27 proteins involved in DNA repair and cancer prevention, suggesting that cell phone-level radiation may disrupt cellular processes that protect against genetic damage.
Simon D et al. · 2013
French researchers exposed lab-grown skin models to cell phone radiation (900 MHz) for 6 hours to see if it affected skin health and structure. While they found no major damage or cell death, the radiation did cause temporary changes in key skin proteins that help maintain the skin's protective barrier. The researchers concluded this could potentially weaken the skin's ability to protect against environmental threats.
Schmid MR et al. · 2012
Researchers exposed 25 healthy men to cell phone-level radio frequency radiation (900 MHz) for 30 minutes before sleep and monitored their brain waves throughout the night. They found that RF exposure altered brain activity patterns during both deep sleep and REM sleep, increasing certain frequencies and changing the normal rhythm of sleep-related brain waves. The study demonstrates that wireless signals can measurably affect brain physiology even after the exposure ends.
Schmid MR et al. · 2012
Swiss researchers exposed 25 young men to cell phone radiation before sleep and monitored their brain waves overnight. The radiation measurably altered brain activity during sleep, changing specific wave patterns even though exposure lasted only 30 minutes before bedtime, demonstrating electromagnetic fields affect brain function.
Schmid MR et al. · 2012
Researchers exposed 30 men to cell phone radiation before sleep and monitored their brain waves. Exposure to signals pulsed at 14 Hz altered deep sleep brain activity, increasing power in frequencies important for sleep quality. This shows wireless signal patterns can affect brain function during sleep.
Schmid MR et al. · 2012
Researchers exposed 30 men to cell phone radiation before sleep and monitored their brain waves overnight. The radiation increased brain activity during deep sleep, particularly when pulsed at frequencies matching natural brain rhythms, showing cell phones can alter sleep patterns hours after use.