Fourth-Generation AirPods
The fourth generation of Apple's AirPods (aka AirPods 4) was introduced in 2024.
The Specific Absorption Rate (or SAR) for the right AirPod is 0.11 watts per kilogram (assessed with the earbud facing the flat phantom and averaged over 1 gram of tissue). The SAR for the left AirPod is 1.19 watts per kilogram (assessed with the earbud's back facing the flat phantom and averaged over 1 gram of tissue) (1).
Third-Generation AirPods
The third generation of Apple's AirPods (aka AirPods 3) was introduced in 2021.
The third generation of Apple's AirPods (aka AirPods 3) was introduced in 2021.
The Specific Absorption Rate (or SAR) for the right AirPod is 0.626 watts per kilogram (assessed via the flat phantom & averaged over 1 gram of tissue) (1). The SAR for the left AirPod is 0.614 watts per kilogram (2).
(2) https://fccid.io/BCG-A2564/RF-
April 2, 2019
Second-Generation AirPods
The newly-released second generation of Apple's AirPods (aka AirPods 2) emits Bluetooth microwave radiation in the 2.402 – 2.480 GHz frequency range to communicate with a smart phone or other wireless device.
The Specific Absorption Rate (or SAR) for the right AirPod is 0.581 watts per kilogram (averaged over 1 gram). (1) The SAR for the left AirPod is 0.501 watts per kilogram. (2)
News about the potential health risks from use of wireless headsets first went viral in 2016 (see posts below). This story has gone viral again at this time for the following reasons:
April 2, 2019
Second-Generation AirPods
The newly-released second generation of Apple's AirPods (aka AirPods 2) emits Bluetooth microwave radiation in the 2.402 – 2.480 GHz frequency range to communicate with a smart phone or other wireless device.
The Specific Absorption Rate (or SAR) for the right AirPod is 0.581 watts per kilogram (averaged over 1 gram). (1) The SAR for the left AirPod is 0.501 watts per kilogram. (2)
News about the potential health risks from use of wireless headsets first went viral in 2016 (see posts below). This story has gone viral again at this time for the following reasons:
- Apple announced that it is taking orders for a new version of its wireless headset, AirPods (aka AirPods 2).
- In the past year, two major studies found conclusive evidence that microwave radiation caused cancer in rats. These studies conducted by the National Toxicology Program in the U.S. and the Ramazzini Institute in Italy received worldwide media coverage.
- The proliferation of new cell towers and antennas in preparation for the deployment of 5G,fifth generation cellular technology, has stimulated many people to seek out information about the health effects from exposure to the radiation these antennas emit on a 24-7 basis in their neighborhoods.
- More people now realize we cannot trust governments to protect us from environmental toxins. Industry has too much influence over government regulatory agencies, and governments have conflicts of interest because the telecom industry pays governments substantial taxes and fees.
For some Bluetooth devices like Apple’s AirPods, the Specific
Absorption Rate (SAR), a measure of the body’s maximum exposure to microwave
radiation, exceeds that of many
smart phones. Moreover, the cumulative exposure to radiation from wireless
headsets may be substantial since many users keep these devices on their head for hours at a time and use them to listen to music or podcasts.
I have found only two small studies that examined the
short-term effects on hearing from exposure to Bluetooth, the communications
standard use in AirPods and other wireless headsets (see below). The health
effects from long-term exposure to this type of microwave radiation have not
been studied.
The FCC minimum exposure levels were adopted in 1996 based
largely upon recommendations from industry-funded scientists and engineers. The
guidelines were designed only to protect us from short-term heating risks. We now
have hundreds of studies that show harmful biologic and health effects from
long-term exposure to low levels of microwave radiation that do not involve
heating. The guidelines need to be updated to protect us from these effects.
Although there is no consensus regarding a safe level of exposure
to microwave radiation, most scientists who have published research on the
effects of this radiation agree that the current exposure limits are much too
permissive. In fact, more than 240 scientists from 42 nations who have
published peer-reviewed research on electromagnetic fields and biology or
health totaling over 2,000 papers in professional journals have signed the International EMF Scientist Appeal which calls for stronger exposure limits and health warnings.
Most wireless safety tips recommend the use of wired headsets or hands-free use of smart phones and other electronic devices instead of wireless headsets.
News Stories
Are AirPods and Other Bluetooth Headphones Safe?
Markham Heid, Medium, March 7, 2019
https://medium.com/s/the-nuance/are-airpods-and-other-bluetooth-headphones-safe-214a0449e13a
Markham Heid, Medium, March 7, 2019
https://medium.com/s/the-nuance/are-airpods-and-other-bluetooth-headphones-safe-214a0449e13a
Are wireless earbuds dangerous? Experts warn that Apple’s
AirPods could send an electromagnetic field through your brain
Natalie Rahhal, Daily Mail, March 11, 2019 Revised March 12
https://www.dailymail.co.uk/health/article-6796679/Are-AirPods-dangerous-250-scientists-warn-be.html
Scientists warn wireless, Bluetooth devices may carry cancer risk
Healio: Hematology/Oncology Today, March 13, 2019
http://bit.ly/BTHealio
Earpods for Cell Phones — Are There Health Risks?
Roxanne Nelson, RN, BSN, Medscape Medical News, March 15, 2019
https://www.medscape.com/viewarticle/910453
Are Bluetooth Headphones Dangerous? Here’s What
Experts Think
Julia Ries, Healthline, March 24, 2019
Controversy surrounding safety of
wireless earphones: News Focus 2 with Prof. Joel Moskowitz
This
Morning, tbs eFM (Seoul, Korea), March 25, 2019 (10 minute audio)
Bethania Palma, Snopes, March 28, 2019
References
(1) UL Verification Services, Inc. SAR Evaluation Report for Bluetooth Earbud. FCC ID: BCG-A2032. Model Name: A2032. Report Number: 12458150-S2V1. Issue Date: 3/15/2019. Fremont, CA. https://fccid.io/BCG-A2032/RF-Exposure-Info/12458150-S2V1-FCC-Report-SAR-4204549
(2) UL Verification Services, Inc. SAR Evaluation Report for Bluetooth Earbud. FCC ID: BCG-A2031. Model Name: A2031. Report Number: 12458150-S1V1. Issue Date: 3/15/2019. Fremont, CA. https://fccid.io/BCG-A2031/RF-Exposure-Info/12458150-S1V1-FCC-Report-SAR-4204479
December 13, 2016
Apple announced today that AirPods can be ordered online and will be available in stores next week. The wireless earbuds will be available in limited quantities in more than 100 countries and territories.
Apple originally planned to ship AirPods in October and has not explained the reason for the delay. The Wall Street Journal reported that the delay was due to problems with the Bluetooth wireless technology employed by this device.
September 12, 2016
Apple’s new AirPods are wireless earbuds that employ Bluetooth technology to communicate with your smart phone, laptop, or smart watch.
According to Apple, “After a simple one-tap setup, AirPods are automatically on and always connected.”
The Specific Absorption Rate (SAR) for the AirPods
The right AirPod emits Bluetooth microwave radiation in the 2.402 – 2.480 GHz frequency range to communicate with a smart phone or other wireless device. The Specific Absorption Rate (or SAR) for the right AirPod is 0.466 watts per kilogram (averaged over 1 gram). (1) The SAR for the left AirPod is 0.510 watts per kilogram. (2)
For more information about the SAR see my post on the iPhone 7.
If one uses the AirPods many hours a day, the cumulative exposure to the brain from this microwave radiation could be substantial.
According to EE Times, the left AirPod communicates with the right AirPod using a different technology, "near field magnetic induction (NFMI)."
Although there is a substantial research literature on the health risks of exposure to magnetic fields, I am not aware of any biologic research that examines NFMI. Hence, this post focuses on the risks to the brain from exposure to Bluetooth radiation.
Is Bluetooth safe?
The wireless industry
argues that devices that use Bluetooth are safe because the microwave
radiation emitted by such devices is low compared to FCC guidelines. The
FCC requires the SAR to be 1.6 watts per kilogram or less.
More than 240 scientists who have published research on electromagnetic radiation safety believe that current national and international guidelines for exposure to radio frequency radiation are inadequate to protect human health (see the
In August 2022, I found only two peer-reviewed studies have examined the effects of exposure to Bluetooth radiation. The studies which employed small samples evaluated the effects of brief exposure to Bluetooth radiation on the auditory system. Given the study limitations, the absence of significant effects is not surprising. These studies do not provide the basis to argue that long-term exposure to Bluetooth radiation is safe.
The following new study suggests there may be long-term effects from Bluetooth exposure, "Epidemiological exploration of the impact of bluetooth headset usage on thyroid nodules using Shapley additive explanations method"
Zhou N, Qin W, Zhang JJ, Wang Y, Wen JS, Lim YM. Epidemiological exploration of the impact of bluetooth headset usage on thyroid nodules using Shapley additive explanations method. Sci Rep. 2024 Jun 21;14(1):14354. doi: 10.1038/s41598-024-63653-0.AbstractWith an increasing prevalence of thyroid nodules globally, this study investigates the potential correlation between the use of Bluetooth headsets and the incidence of thyroid nodules, considering the cumulative effects of non-ionizing radiation (NIR) emitted by these devices. In this study, we analyzed 600 valid questionnaires from the WenJuanXing platform using Propensity Score Matching (PSM) and the XGBOOST model, supplemented by SHAP analysis, to assess the risk of thyroid nodules. PSM was utilized to balance baseline characteristic differences, thereby reducing bias. The XGBOOST model was then employed to predict risk factors, with model efficacy measured by the area under the Receiver Operating Characteristic (ROC) curve (AUC). SHAP analysis helped quantify and explain the impact of each feature on the prediction outcomes, identifying key risk factors. Initially, 600 valid questionnaires from the WenJuanXing platform underwent PSM processing, resulting in a matched dataset of 96 cases for modeling analysis. The AUC value of the XGBOOST model reached 0.95, demonstrating high accuracy in differentiating thyroid nodule risks. SHAP analysis revealed age and daily Bluetooth headset usage duration as the two most significant factors affecting thyroid nodule risk. Specifically, longer daily usage durations of Bluetooth headsets were strongly linked to an increased risk of developing thyroid nodules, as indicated by the SHAP analysis outcomes. Our study highlighted a significant impact relationship between prolonged Bluetooth headset use and increased thyroid nodule risk, emphasizing the importance of considering health impacts in the use of modern technology, especially for devices like Bluetooth headsets that are frequently used daily. Through precise model predictions and variable importance analysis, our research provides a scientific basis for the formulation of public health policies and personal health habit choices, suggesting that attention should be paid to the duration of Bluetooth headset use in daily life to reduce the potential risk of thyroid nodules. Future research should further investigate the biological mechanisms of this relationship and consider additional potential influencing factors to offer more comprehensive health guidance and preventive measures.
Open access paper: https://www.nature.com/articles/s41598-024-63653-0
Low-intensity microwave radiation can open the blood-brain barrier
In 1975, Allan Frey published a paper in the Annals of the New York Academy of Sciences which reported that exposure to low intensity microwave radiation could open the blood-brain barrier in rats. Moreover, pulsed radio frequency waves (like Bluetooth) were more likely to produce this effect than continuous waves. (3)
In 1975, Allan Frey published a paper in the Annals of the New York Academy of Sciences which reported that exposure to low intensity microwave radiation could open the blood-brain barrier in rats. Moreover, pulsed radio frequency waves (like Bluetooth) were more likely to produce this effect than continuous waves. (3)
The blood-brain barrier is a special layer of cells in the brain that prevents chemical toxins in the blood system from reaching the brain. Breaching this barrier could potentially lead to neurodevelopmental and neurodegenerative diseases and brain cancer.
The effect of microwave radiation on the blood-brain barrier is nonlinear—it occurs with low intensity exposures but not at higher intensity exposures.
Although other published studies have failed to find the blood-brain barrier effect, these studies tended to use higher intensity exposures or employed small samples.
Recommendations
We may not be certain of the long-term risks of using Bluetooth devices, but why would anyone insert microwave-emitting devices in their ears near their brain when there are safer ways to use a cell phone?
I recommend
the use of corded headsets or hands-free use of cell phones, not wireless earbuds. Moreover, one should never keep a cell phone next to your body,
especially during a phone call, but also whenever the phone is powered on. For additional tips on how to reduce your exposure to wireless radiation see https://www.saferemr.com/2015/10/tips-to-reduce-your-wireless-radiation.html.
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News coverageIn the past few days, numerous news stories have appeared citing industry-affiliated scientists who claim that AirPods are safe. Nonetheless, a few news reports have addressed the potential health risks from using AirPods:
·
CBS San Francisco: "Apple Unveils iPhone 7 Without Headphone Jack"
·
Daily
Mail: “Could wireless headphones harm your health?”
Since the stories in the Daily Mail and CNN were posted on September 8, over two dozen online news stories have appeared that discuss the potential health risks from the microwave radiation emitted by AirPods.
References (updated 1/13/2025)
(1) UL
Verification Services, Inc. SAR Evaluation Report for Wireless Headset. FCC ID:
BCG-A1523. Model Name: A1523. Report Number: 16U23784-S6V1. Issue Date: 8/30/2016.
Fremont, CA. https://fccid.io/document.php?id=3118442
(2) UL Verification Services, Inc. SAR Evaluation Report for Wireless Headset. FCC ID: BCG-A1722. Model Name: A1722. Report Number: 16U23784-S1V1. Issue Date: 8/30/2016. Fremont, CA. https://fccid.io/BCG-A1722/RF-Exposure-Info/16U23784-S1V1-FCC-SAR-Report-3118428.pdf
(3) 3 peer-reviewed studies that reported on the effects of brief exposure to Bluetooth radiation:
Zhou N, Qin W, Zhang JJ, Wang Y, Wen JS, Lim YM. Epidemiological exploration of the impact of bluetooth headset usage on thyroid nodules using Shapley additive explanations method. Sci Rep. 2024 Jun 21;14(1):14354. doi: 10.1038/s41598-024-63653-0. https://pmc.ncbi.nlm.nih.gov/articles/PMC11192738/
Mandalà M, Colletti V, Sacchetto L, Manganotti P, Ramat S, Marcocci A, Colletti L. Effect of Bluetooth headset and mobile phone electromagnetic fields on the human auditory nerve. Laryngoscope. 2014 Jan;124(1):255-9. http://www.ncbi.nlm.nih.gov/pubmed/23619813
Balachandran R, Prepageran N, Rahmat O, Zulkiflee AB, Hufaida
KS. Effects of Bluetooth device electromagnetic field on hearing: pilot study.
J Laryngol Otol. 2012 Apr;126(4):345-8. http://www.ncbi.nlm.nih.gov/pubmed/22310164
(4) 16 peer-reviewed studies that reported significant evidence of opening of the blood-brain barrier from exposure to low-intensity microwave radiation:
Kizilçay AO, Tütüncü B, Koçarslan M, Gözel
MA. Effects of 1800 MHz and 2100 MHz mobile phone radiation on the
blood-brain barrier of New Zealand rabbits. Med Biol Eng Comput. 2024
Nov 16. doi: 10.1007/s11517-024-03238-1. https://pubmed.ncbi.nlm.nih.
Sırav B,
Seyhan N. Effects of GSM modulated radio-frequency electromagnetic radiation on
permeability of blood-brain barrier in male & female rats. J Chem
Neuroanat. 2016 Sep;75(Pt B):123-7 23. http://www.ncbi.nlm.nih.gov/pubmed/26723545
Tang J, Zhang
Y, Yang L, Chen Q, Tan L, Zuo S, Feng H, Chen Z, Zhu G. Exposure to 900MHz
electromagnetic fields activates the mkp-1/ERK pathway and causes blood-brain
barrier damage and cognitive impairment in rats. Brain Res. 2015 Jan 15. http://www.ncbi.nlm.nih.gov/pubmed/25598203
Sirav B, Seyhan N. Effects of radiofrequency radiation exposure on blood-brain barrier permeability in male and female rats. Electromagn Biol Med. 2011 Dec;30(4):253-60. http://www.ncbi.nlm.nih.gov/pubmed/22047463
Sirav B,
Seyhan N. Blood-brain barrier disruption by continuous-wave radio frequency
radiation. Electromagn Biol Med. 2009;28(2):215-22. http://www.ncbi.nlm.nih.gov/pubmed/19811403
Nittby H,
Brun A, Eberhardt J, Malmgren L, Persson BR, Salford LG. Increased blood-brain
barrier permeability in mammalian brain 7 days after exposure to the radiation
from a GSM-900 mobile phone. Pathophysiology. 2009 Aug;16(2-3):103-12. http://www.ncbi.nlm.nih.gov/pubmed/19345073
Söderqvist F,
Carlberg M, Hansson Mild K, Hardell L. Exposure to an 890-MHz mobile phone-like
signal and serum levels of S100B and transthyretin in volunteers. Toxicol Lett.
2009 Aug 25;189(1):63-6. http://www.ncbi.nlm.nih.gov/pubmed/19427372
Eberhardt JL, Persson BR, Brun AE, Salford LG, Malmgren LO. Blood-brain barrier permeability and nerve cell damage in rat brain 14 and 28 days after exposure to microwaves from GSM mobile phones. Electromagn Biol Med. 2008;27(3):215-29. http://www.ncbi.nlm.nih.gov/pubmed/18821198
Belyaev IY, Koch CB, Terenius O, Roxström-Lindquist K, Malmgren LO, H Sommer W, Salford LG, Persson BR. Exposure of rat brain to 915 MHz GSM microwaves induces changes in gene expression but not double stranded DNA breaks or effects on chromatin conformation. Bioelectromagnetics. 2006 May;27(4):295-306. http://www.ncbi.nlm.nih.gov/pubmed/16511873
Salford LG, Brun AE, Eberhardt JL, Malmgren L, Persson BR. Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phones. Environ Health Perspect. 2003 Jun;111(7):881-3; discussion A408. http://www.ncbi.nlm.nih.gov/pubmed/12782486
Leszczynski D, Joenväärä S, Reivinen J, Kuokka R. Non-thermal activation of the hsp27/p38MAPK stress pathway by mobile phone radiation in human endothelial cells: molecular mechanism for cancer- and blood-brain barrier-related effects. Differentiation. 2002 May;70(2-3):120-9. http://www.ncbi.nlm.nih.gov/pubmed/12076339
Schirmacher A, Winters S, Fischer S, Goeke J, Galla HJ, Kullnick U, Ringelstein EB, Stögbauer F. Electromagnetic fields (1.8 GHz) increase the permeability to sucrose of the blood-brain barrier in vitro. Bioelectromagnetics. 2000 Jul;21(5):338-45. http://www.ncbi.nlm.nih.gov/pubmed/10899769
Fritze K, Sommer C, Schmitz B, Mies G, Hossmann KA, Kiessling M, Wiessner C. Effect of global system for mobile communication (GSM) microwave exposure on blood-brain barrier permeability in rat. Acta Neuropathol. 1997 Nov;94(5):465-70. http://www.ncbi.nlm.nih.gov/pubmed/9386779
Salford LG, Brun A, Sturesson K, Eberhardt JL, Persson BR. Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50, and 200 Hz. Microsc Res Tech. 1994 Apr 15;27(6):535-42. http://www.ncbi.nlm.nih.gov/pubmed/8012056
Persson BR,
Salford LG, Brun A, Eberhardt JL, Malmgren L. Increased permeability of the
blood-brain barrier induced by magnetic and electromagnetic fields. Ann N Y
Acad Sci. 1992 Mar 31;649:356-8. http://www.ncbi.nlm.nih.gov/pubmed/1580510
Frey AH, Feld SR, Frey B. Neural function and behavior: Defining the relationship. Annals of the New York Academy of Sciences, 247: 433–439. 1975. http://www.ncbi.nlm.nih.gov/pubmed/46734
