Tuesday, December 13, 2016

AirPods: Are Apple’s New Wireless Earbuds Safe?

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 left 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) of the AirPod is 0.466 watts per kilogram (averaged over 1 gram). (1)  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 220 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 International EMF Scientist Appeal).

I could find only two peer-reviewed studies that 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. (2) 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.

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)

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.

More than a dozen peer-reviewed studies have replicated Frey's findingsexposure to low intensity microwave radiation can open the blood-brain barrier (see links below). (3)  

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.


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 http://bit.ly/safewirelesstips.

News coverage

In 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.


(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://apps.fcc.gov/eas/GetApplicationAttachment.html?id=3118442

(2) Peer-reviewed studies which reported on the effects of brief exposure to Bluetooth radiation:

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

(3) Peer-reviewed studies which reported opening of the blood-brain barrier from exposure to low-intensity microwave radiation:

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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?dopt=Abstract

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.

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.