Monday, October 24, 2016

Do iPhones emit more radiation than Samsung Galaxy phones?

Caveat Emptor:  In the following post, I re-iterate the concern of the U.S. Government Accountability Office (GAO) that it is deceptive for the FCC to apply the SAR test in a manner that does not reflect how consumers actually use cell phones. I am not endorsing use of the SAR test for cell phone safety certification because the test fails to address the risks from exposure to non-thermal levels of microwave radiation. We need to adopt biologically-based safety limits and an appropriate testing procedure. See my earlier post, "What's Wrong with Cellphone Radiation Safety Limits," for more information.
Several recent news stories reported that Apple iPhones emit twice as much radiation as Samsung Galaxy phones (Cho Mu-Hyun, “iPhones 'emit double the radiation' of Galaxy handsets: Korean agency,” ZDNet, September 27, 2016). This story has been reported in Australia, China, France, India, Japan, and South Korea.

According to Yonhap News Agency, Representative Choi Myung-gil who serves on the South Korean Assembly’s Telecommunications Committee stated that six Apple products received a Tier 2 rating from the country's National Radio Research Agency (NRRA). In contrast, all Samsung products received a Tier 1 rating. The Tier 1 rating is awarded to mobile devices with a Specific Absorption Rate (SAR) below 0.8 watts/kilogram (W/kg) whereas devices with a higher SAR are given a Tier 2 rating.

Representative Choi also expressed concern that the SAR has been increasing over time for all cell phones and tablets and asked his government to do more to protect the public from wireless radiation exposure.

In the United States, the Federal Communications Commission (FCC) considers all cell phones with a SAR of 1.60 W/kg or less to be safe. Unlike Korea and Belgium (below), the FCC discourages consumers from comparing SARs when selecting a phone. According to the FCC:

“ALL cell phones must meet the FCC’s RF exposure standard, which is set at a level well below that at which laboratory testing indicates, and medical and biological experts generally agree, adverse health effects could occur. For users who are concerned with the adequacy of this standard or who otherwise wish to further reduce their exposure, the most effective means to reduce exposure are to hold the cell phone away from the head or body and to use a speakerphone or hands-free accessory. These measures will generally have much more impact on RF energy absorption than the small difference in SAR between individual cell phones, which, in any event, is an unreliable comparison of RF exposure to consumers, given the variables of individual use.”

What is the full story?

The SAR is a measure of the maximum amount of microwave radiation absorbed by a test dummy, not the amount of microwave radiation emitted by a wireless device. Moreover, according to a report by the U.S. Government Accountability Office (GAO), the SAR does not provide an accurate representation of the amount of radiation that the typical cell phone user’s head and body absorb over time. For more information about how to interpret the SAR see the links at the end of this article.


The tier rating classifications in Korea are misleading because they only account for the SAR tested at the head. Furthermore, they only address the situation when Wi-Fi and Bluetooth are turned off while testing cellular transmission.

When tested near the head with W-Fi and Bluetooth turned off, the iPhone 7 does indeed have higher SARs than Galaxy 7 smartphones. However, in simultaneous mode with Wi-Fi and Bluetooth turned on along with the cellular transmitter(s), the iPhones and Galaxy phones have similar SARs near the head. According to test reports filed with the FCC, without Wi-Fi and Bluetooth, iPhone SARs ranged from 1.09 to 1.19 W/kg as compared to 0.62 to 0.64 W/kg for Galaxy phones (see results below). However in simultaneous mode with Wi-Fi and Bluetooth turned on, iPhone SARs ranged from 1.42 to 1.49 W/kg as compared to 1.40 to 1.56 W/kg for Galaxy phones.

Unlike the SAR head test which is conducted at a fixed distance from the test dummy (about 6 millimeters), the SAR body test can be conducted at different distances from the dummy (up to 25 millimeters). The distance is selected by the phone’s manufacturer. SAR values from phones tested at different distances from the dummy should not be directly compared because they are not comparable.

Although with Wi-Fi and Bluetooth turned off, the iPhone 7 and Galaxy 7 smartphones appear to have similar body SARs, these phones were tested at different distances from the body. The iPhones were tested at 5 millimeters, and the Galaxy phones were tested at 15 millimeters. If the Galaxy phones had been tested at 5 millimeters, the SAR values would likely have been between 1.73 and 2.78 W/kg. (These estimates are based on research by Om Gandhi which found that SAR increases 5% to 10% for each millimeter closer to the body.) Moreover, since the body SARs for the iPhone ranged from 1.09 to 1.14 W/kg, the body is exposed to less radiation from an iPhone than a Galaxy phone when Wi-Fi and Bluetooth are turned off.

Based upon SAR test results, when Wi-Fi and Bluetooth are turned on in addition to cellular, the body absorbs considerably less radiation from an iPhone, whereas the head absorbs similar amounts of radiation as compared to Galaxy phones. 

FCC needs to standardize the body SAR test

The FCC should standardize the distance from the test dummy for the SAR body test. Since hardly anyone uses a manufacturer-approved cell phone holder to keep the phone away from their body, there is no justification for allowing phones to be tested at different distances from the dummy. Also, consumers who wanted to compare the body SARs from different phones would then be able to do so.

All phones should be tested next to the body where people actually keep their cell phones. However, it is likely that no phone would pass the test and be certified for sale in the U.S. 

Some phones may even fail the SAR test with a 5 millimeter body separation distance. For example, the Samsung Galaxy 7 phones would not likely have been certified for sale because the maximum SAR allowed in the U.S. or Korea is 1.60 W/kg, and the body SARs would have exceeded this limit if the phones were tested at 5 millimeters.

Belgium’s 5-tier safety system for cell phones

Belgium has a 5-tier safety classification system. All cell phones in Belgium are labeled with the letter A, B, C, D, or E, corresponding to the phone's head SAR (averaged over 10 grams of simulated tissue):
  • "A" indicates a SAR less than 0.4 watts/kilogram (W/kg),
  • "B" from 0.4 to less than 0.8 W/kg, 
  • "C" from 0.8 to less than 1.2 W/kg, 
  • "D" from 1.2 to less than 1.6 W/kg, and 
  • "E" more than 1.6 W/kg.
In Belgium it is compulsory to display a poster at the point of sale that explains the SAR-value categories and advises the consumer to make phone calls wearing an earpiece and to choose a mobile phone with a lower radiation value.

“Think about your health – use your mobile phone moderately, make your calls wearing an earpiece and choose a set with a lower SAR value.”


SARs reported to the 
Federal Communications Commission

The maximum SAR allowed in the U.S. and Korea is 1.60 W/kg averaged over one gram of simulated tissue. The SARs reported below were averaged over one gram. 

Apple

iPhone 7 (Model A1660: GSM and CDMA)
Head = 1.10 watts per kilogram (W/kg) 
Body = 1.14 W/kg
Hotspot = 1.16 W/kg
Simultaneous (cellular plus Wi-Fi) = 1.49 W/kg (head), 1.56 W/kg (body), 1.56 W/kg (hotspot)

iPhone 7 (Model A1778: GSM, no CDMA) 
Head = 1.19 W/kg 
Body = 1.09 W/kg
Hotspot = 1.14 W/kg
Simultaneous (cellular plus Wi-Fi) = 1.56 W/kg (head), 1.51 W/kg (body), 1.58 W/kg (hotspot)

iPhone 7 Plus (Model A1661: GSM and CDMA)
Head = 1.09 W/kg 
Body = 1.10 W/kg
Hotspot = 1.13 W/kg
Simultaneous (cellular plus Wi-Fi) = 1.45 W/kg (head), 1.51 W/kg (body), 1.58 W/kg (hotspot)

iPhone 7 Plus (Model A1784: GSM, no CDMA) 
Head = 1.09 W/kg 
Body = 1.14 W/kg
Hotspot = 1.14 W/kg
Simultaneous (cellular plus Wi-Fi) = 1.42 W/kg (head), 1.54 W/kg (body), 1.54 W/kg (hotspot)

Samsung

Galaxy S7
Head = 0.62 W/kg 
Body = 1.06 W/kg
Hotspot = 0.55 W/kg (head)
Simultaneous (cellular plus Wi-Fi) = 1.40 W/kg (head), 1.50 W/kg (body), 1.59 W/kg (hotspot)

Galaxy S7 Edge
Head = 0.64 W/kg 
Body = 1.07 W/kg
Hotspot = 1.10 W/kg
Simultaneous (cellular plus Wi-Fi) = 1.56 W/kg hotspot


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