IEEE Consumer Electronics Magazine - November/December 2020 - 42

5G in Consumer Electronics

deployed due to employment of small cells. As a
direct consequence, BSs serve smaller geographic areas and thus are located closer to
human users, which again results in a higher
chance of a human user being exposed to EMF.
Third, directional beams will be employed in
5G as a solution for faster attenuation of a signal
power due to operation in high-frequency
bands.4 Notice that the main purpose of using
such a multiple-antenna system is to increase
the antenna gain. This higher concentration of
electromagnetic energy results in a greater
potential for an EMF to penetrate further into a
human body.

CURRENT UNDERSTANDING
AND EFFORT

While substantial attention has been paid to
technical advancements that the 5G will introduce, the potential impacts that the technology
may pose on human health have not been discussed as closely and thoroughly.

Health Effect
"Heating" of skin is one representative impact
on a human body caused by EMF exposure. The
temperature for a skin outer surface normally
ranges from 30 to 35 C. The pain-detection
threshold temperature for human skin is approximately 43  C14 and any temperature exceeding it
can cause a long-term injury. Heating is considered as a significant impact since it can cause subsequent effects such as cell damage and protein
induction.5 It is also known that high-frequency
EMF affects the sweat glands (which may serve as
helical antennas), peripheral nerves, the eyes,
and the testes, and may have indirect effects on
many organs in the body.6
Recent studies showed health impacts of
EMF in frequencies above 6 GHz. In a latest
study,7 EMF power transmitted to the body was
analyzed as a function of angle of incidence and
polarization, and its relevance to the current
guidelines was discussed. Another study8 determined a maximum averaging area for power density (PD) that limits the maximum temperature
increase to a given threshold. Also, considering
"bursty" traffic patterns in modern wireless
data communications, an analytical approach to

42

"pulsed" heating was developed and applied to
assess the peak-to-average temperature ratio as
a function of the pulse fraction.9

Acknowledgement by Organizations
The United States (U.S.) Federal Communications Commission (FCC)10 and the International
Commission on Non-Ionizing Radiation Protection (ICNIRP)11 set guidelines on the maximum
amount of EMF energy allowed on a human
body. It is noteworthy that the FCC's guideline
on specific absorption rate (SAR) is averaged
over 1 gram (g) of tissue while that set by the
ICNIRP is averaged over 10 g. It implies that
the FCC's guideline is more conservative, while
the ICNIRP allows for two to three times as much
energy absorption.
Also, the U.S. Food and Drug Administration
(FDA) states that the current understanding on
adverse impacts of EMF emissions on human
health is insufficient to conclude whether exposure to the emissions is safe or not, and thus,
additional research is needed to address the current gaps in the literature on human health
safety in use of wireless systems.12
Meanwhile, the World Health Organization
(WHO)'s International Agency for Research on
Cancer (IARC) classifies EMF exposure as possibly carcinogenic.13
Measurements
PD and SAR are the two most widely accepted
metrics to measure the intensity and effects of
EMF exposure.15 However, selection of an appropriate metric evaluating the EMF exposure still
remains controversial. The FCC suggests PD as a
metric measuring the human exposure to EMF
generated by devices operating at frequencies
higher than 6 GHz,10 whereas a recent study suggested that a guideline defined in PD is not efficient to determine the impacts on health issues
especially when devices are operating in a very
close proximity to the human body such as in an
uplink.14
However, PD cannot evaluate the effect of
certain transmission characteristics (e.g., reflection) adequately. Thus, temperature elevation
and SAR at a direct contact area are proposed as
the appropriate metric for EMF exposure above
6 GHz.16 This article chooses SAR as a more

IEEE Consumer Electronics Magazine
IEEE Consumer Electronics Magazine - November/December 2020

Table of Contents for the Digital Edition of IEEE Consumer Electronics Magazine - November/December 2020
