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
Dragicevic N et al. · 2011
Researchers exposed mice to 918 MHz electromagnetic fields daily for one month. The treatment dramatically boosted brain cell energy production by 50-150% in Alzheimer's mice and improved function in normal mice, suggesting EMFs might protect against cognitive decline.
Bourthoumieu S et al. · 2011
Researchers exposed human cells to GSM-900 MHz cell phone radiation for 24 hours at various power levels to see if it caused aneuploidy (abnormal chromosome numbers that can lead to genetic disorders). They found no significant changes in chromosome structure even at the highest exposure level of 4 W/kg. This suggests that cell phone radiation at these levels does not cause this particular type of genetic damage in laboratory conditions.
Arendash GW et al. · 2010
Researchers exposed mice to cell phone-level radiation (918 MHz) and found it improved memory and reduced Alzheimer's-related brain deposits in both normal and Alzheimer's mice. While promising for potential treatments, these mouse results require extensive human studies before any clinical applications.
Bourthoumieu S et al. · 2010
Researchers exposed human cells to GSM-900 MHz radiation (the type used by 2G mobile phones) for 24 hours to see if it caused genetic damage. Using advanced chromosome analysis techniques, they found no evidence of DNA damage or chromosomal changes at a specific absorption rate of 0.25 W/kg. This study adds to the scientific debate about whether cell phone radiation can harm our genetic material.
Arendash GW et al. · 2010
Researchers exposed mice to cell phone radiation (918 MHz) for one hour daily over eight months. The exposure improved memory and reduced Alzheimer's-related brain plaques in both normal and Alzheimer's-prone mice, suggesting certain electromagnetic fields might benefit brain health.
Joubert V, Leveque P, Cueille M, Bourthoumieu S, Yardin C. · 2007
French researchers exposed rat brain neurons to cell phone radiation (900 MHz GSM) for 24 hours at levels similar to phone use (0.25 W/kg SAR) to see if it would cause cell death (apoptosis). Using three different testing methods, they found no increase in neuron death compared to unexposed control cells. This suggests that short-term cell phone radiation exposure may not directly kill brain cells under these laboratory conditions.
Joubert V, Leveque P, Cueille M, Bourthoumieu S, Yardin C. · 2007
French researchers exposed rat brain neurons to cell phone radiation (900 MHz GSM) for 24 hours at levels similar to phone use, then tested whether the radiation caused brain cells to die through a process called apoptosis. Using three different measurement methods, they found no increase in cell death compared to unexposed neurons. This suggests that brief cell phone radiation exposure may not directly damage brain cells in the way some scientists have theorized.
Utteridge TD et al. · 2002
Researchers exposed cancer-prone mice to cell phone radiation (898.4 MHz) for up to 2 years at various intensities to see if it increased lymphoma rates. They found no significant increase in cancer incidence at any exposure level, even in mice genetically predisposed to develop lymphomas. This study contradicted an earlier 1997 study that found increased cancer risk from similar radiofrequency exposure.
Finnie JW et al. · 2002
Researchers exposed mice to cell phone radiation (900 MHz) for two years to test blood-brain barrier damage. They found minimal blood vessel leakage in both exposed and control groups, suggesting typical cell phone use may not compromise this critical brain protection system.
Tsurita G, Nagawa H, Ueno S, Watanabe S, Taki M, · 2000
Japanese researchers exposed rats to 1439 MHz radiofrequency radiation (similar to cell phone signals) for one hour daily over 2-4 weeks to test whether it damaged the blood-brain barrier or caused brain tissue changes. They found no effects on blood-brain barrier permeability, no structural damage to brain cells, and no changes in body weight at exposure levels up to 2 W/kg in the brain. This suggests that short-term exposure to cell phone-type radiation at these levels may not cause detectable brain damage in rats.
Higashikubo R et al. · 1999
Researchers exposed rats with brain tumors to cell phone-like radiofrequency radiation for 4 hours daily over several months to see if the radiation would affect tumor growth. The study found no difference in survival rates between rats exposed to RF radiation and those that weren't exposed. This suggests that RF radiation at levels similar to cell phones doesn't accelerate brain tumor growth in this animal model.
López-Martín E et al. · 2009
Spanish researchers exposed rats to cell phone signals for 2 hours and found that pulsed GSM radiation affected brain activity differently than continuous radiation of equal strength. The pulsed signals altered gene activity in brain areas controlling seizures, emotions, and memory, suggesting unique biological effects beyond heating.
Favre D · 2011
Researchers placed active mobile phones near honeybee colonies and recorded the bees' sounds to see if cell phone radiation affected their behavior. They found that phones operating at 900 MHz caused bees to produce 'worker piping' signals, which normally indicate either preparation for swarming or that the colony is under stress. This suggests that cell phone radiation can disrupt normal bee communication and behavior patterns.
Sannino A et al. · 2014
Researchers exposed human blood cells to radiofrequency radiation (similar to cell phone signals) for 20 hours, then subjected them to X-ray radiation. Surprisingly, the cells that received the RF pre-exposure showed significantly less genetic damage from the X-rays compared to cells that only received X-rays. This suggests that low-level RF exposure may trigger protective mechanisms that help cells resist subsequent DNA damage.
Razavinasab M, Moazzami K, Shabani M · 2014
Pregnant rats exposed to 900 MHz cell phone radiation for six hours daily produced offspring with altered brain cell activity and impaired memory performance. The rat pups showed decreased neuron firing and worse learning test results, suggesting prenatal phone radiation exposure may affect developing brain function.
Zeni et al. · 2007
Researchers exposed mouse cells to 900 MHz cell phone radiation for up to 30 minutes to test whether it creates harmful molecules called reactive oxygen species. The radiation did not increase these damaging molecules at any exposure level tested, suggesting no immediate cellular harm.
Kumlin T et al. · 2007
Finnish researchers exposed young rats to cell phone radiation (900 MHz) for 2 hours daily over 5 weeks. Unexpectedly, exposed rats showed improved learning and memory performance with no brain damage or blood-brain barrier problems, suggesting cognitive enhancement that warrants further investigation.
Zeni O et al. · 2007
Researchers exposed mouse cells to 900 MHz cell phone radiation for up to 30 minutes to test whether it creates harmful reactive oxygen species that damage cells. The study found no increase in these damaging molecules from RF exposure alone, suggesting this frequency may not cause oxidative cellular stress.
Heikkinen et al. · 2006
Finnish researchers exposed female rats to 900 MHz radiofrequency radiation (similar to cell phone frequencies) for 2 hours daily over 2 years while also giving them a known cancer-causing chemical in their drinking water. The study aimed to see if RF radiation would make tumors more likely to develop. The researchers found no evidence that RF radiation increased cancer risk, even when combined with a chemical known to cause tumors.
Verschaeve et al. · 2006
Researchers exposed female rats to mobile phone radiation (900 MHz) for 2 hours daily over 2 years, while also giving them a known cancer-causing chemical in their drinking water. They wanted to see if the radiation would make the chemical's DNA damage worse. The study found no evidence that the radiofrequency radiation enhanced the genetic damage caused by the toxic chemical.
Verschaeve L et al. · 2006
Researchers exposed female rats to cell phone radiation (900 MHz) for 2 years while also giving them a known cancer-causing chemical in their drinking water to see if the radiation would make DNA damage worse. They found that the radiation alone didn't cause genetic damage, and it didn't increase the DNA damage caused by the chemical. This suggests that long-term exposure to cell phone-level radiation may not enhance the harmful effects of other toxins on our genetic material.
Zeni O et al. · 2005
Italian researchers exposed human white blood cells to 900 MHz cell phone radiation for 2 hours at levels similar to what phones emit during calls. They tested multiple ways to detect DNA damage but found no statistically significant genetic harm at either exposure level tested. The study suggests that short-term exposure to cell phone radiation at typical use levels may not cause immediate DNA damage in blood cells.
Fritze K et al. · 1997
Scientists exposed rats to cell phone radiation for 24 hours at different power levels. Only the highest exposure caused temporary stress protein increases in brain cells, with effects disappearing within a day. This suggests brief cellular stress occurs at extreme levels but causes no lasting brain damage.
Esmekaya MA et al. · 2016
Researchers exposed mice to cell phone radiation (900 MHz) before, during, and after chemically-induced seizures to study brain effects. They found that radiation exposure significantly increased oxidative damage and inflammatory markers in brain tissue compared to seizures alone. This suggests cell phone radiation may worsen brain vulnerability during neurological stress, potentially making seizure-related brain damage more severe.
Hinrikus H, Bachmann M, Lass J, Karai D, Tuulik V. · 2008
Researchers exposed 66 healthy volunteers to low-level microwave radiation at various frequencies and measured their brain activity using EEG. They found that microwave exposure increased brain energy levels, with 13-31% of subjects showing significant changes in their brain wave patterns depending on the frequency used. The study demonstrates that microwave radiation can alter normal brain function even at exposure levels considered safe by current standards.