Answer to Question #11269 Submitted to "Ask the Experts"

Category: Micro/Radio Waves, Radar & Powerlines — Microwaves and Radiofrequency

The following question was answered by an expert in the appropriate field:

Q

Are there adverse health effects from wearing an eyeglass-style computer like Google Glass? Are the levels of electromagnetic radiation from these devices similar to cellular phones or Bluetooth headphones? What are the levels?

A

Wearable computers such as Google Glass have a wireless communications capability that necessarily results in some level of radiofrequency (RF) exposure to the user. However, the exposure levels are certainly very low given the small amount of power that is transmitted.

Google Glass (which is presently not on the market) has two transmitters, a 5 milliwatt (5 mW) Bluetooth transmitter and a 30 mW Wi-Fi transmitter, using an antenna that is mounted in the right earpiece of the device and faces away from the head. The duty cycle of transmission (time spent transmitting power) is very low, so the average exposure over time from such devices will be very small.

Google Glass, as with any RF-emitting device, has to comply with government safety limits, which in the United States are those of the Federal Communications Commission (FCC). In 2013, Google submitted test data to the FCC showing that the device complies with FCC limits by a substantial margin. These tests were done according to FCC requirements, which results in a considerable overestimate of the actual exposure to the user under any realistic usage conditions.

As a practical matter, Google Glass presents minimal exposure to the user, certainly in comparison to that from a cell phone which may operate at 10 times higher power levels than Glass. The "worst case" exposure scenario is when the device is pulled forward from the head, placing the antenna directly against the pinna (the soft outer part of the ear). Even in this unlikely event, the Google report indicates that the RF exposure to the user will still be below FCC exposure limits, and most of the exposure will occur in the pinna.

I would personally be more concerned about the potential for driver distraction, similar to that from texting while driving. Because this product category is so new, ergonomic factors, including potential hazards from distraction, have been little explored but caution is certainly in order when using such devices while operating potentially dangerous equipment.

Kenneth R. Foster
Department of Bioengineering
University of Pennsylvania

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 27 July 2015. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.