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Radiofrequency
(RF) Radiation
Cell phones, radar and radio
transmitters, and many other sources expose us all to RF waves, including
microwaves (MW). At high levels, tissue heating (thermal) effects are well
known and familiar to MW oven users. Overexposure
to RF radiation can cause adverse health effects. At lower levels, RF may disrupt some
electronic medical implants like pacemakers
and insulin pumps.
International epidemiological surveys
show that a small percentage of the global population report non-specific
symptoms of electrohypersensitivity including
skin reactions, headaches and heart palpitations. Study of self-reported hypersensitivity to electromagnetic
fields in California. | Environmental Health Perspectives | Vol. 110, No.
suppl 4
Scientists agree more research is needed in some areas.
Based on current knowledge, government and science bodies have
set RF exposure limits. There is evidence that biological effects do occur
below these limits, however it has not been determined whether such
exposures cause adverse health effects.
The International Agency for Research on Cancer (IARC) rates
RF as a possible carcinogen.
What does the IARC mean by possible? IARC has sorted over 1,000 chemical,
physical, and biological agents into one of four groups based on the
scientific evidence. Group 1 is known
to cause cancer. This group includes alcoholic drinks and diesel exhaust.
Group 2A is probable, including
things like red meat consumption. RF is in Group 2B, possible, which also includes things like aloe vera and
gasoline. Group 3 is not classifiable
due to lack of evidence and includes tea and jet fuel. IARC based placing
RF in Group 2B based on some studies linking brain cancers to wireless
phone use.
IARC
classified RF as possibly carcinogenic
Subsequent animal studies also showed a possible
carcinogenic link.� National
Toxicology Program study.� However, during the past two decades of huge
growth in cell phone use, U.S. brain cancer rates have remained fairly steady. National
Cancer Institute National Trends in New Cancer Rates.
Definitions
The frequency of an RF signal is
usually expressed in terms of a unit called the hertz (Hz). One Hz equals
one cycle per second. One megahertz (MHz) equals one million cycles per
second. Radiofrequency falls between 300 gigahertz (GHz) and 3 kilohertz
(kHz). Within this frequency range, there are:
Microwaves in the 300 GHz to 300 MHz
frequency range. Sources of microwaves are some mobile/cell phones, microwave
ovens, cordless phones, motion detectors, long-distance telecommunications,
radar, and Wi-Fi. Microwaves can
cause damage through heating of body tissue.
Radio Waves in the 300 MHz to 3 kHz
frequency range. Naturally occurring
radio waves are made by lightning or by astronomical objects. Human
produced radio waves are used for mobile/cell phones, smart meters,
televisions, FM and AM radios, shortwave radios, CB radios, cordless
phones, broadcasting, radar and other navigation systems, satellite communication,
computer networks and other applications.
Smart Meters
Smart Meters are deployed in many
places to help create a new "smart grid" of utility services that
can respond quickly, be more efficient, and reduce costs. Smart meters work
by transmitting RF data. Some people are concerned about possible health
effects of these RF signals as smart meters become wide
spread. Key findings of a 2011 study Health
Impacts of Radio Frequency from Smart Meters by the California Council
of Science and Technology include:
Smart meters give much lower levels
of RF than common household devices like cell phones and MW ovens.
FCC rules protect against known
thermal health impacts of common household devices and smart meters.
If exposure to smart meters is
a concern, opt to not use them in your home. Duke Energy has an Opt Out Program for their utility
meters.
Smart
Meters -� What
We Know Federal Communications Commission (FCC)
5G Cellular Networks
5G differs from prior wireless
networks in a few ways. Some 5G cell phones use the same roughly 600 MHz to
900 MHz range as older networks. However, most 5G networks use the part of
the spectrum above 3 GHz (3000 MHz).
These higher frequencies carry more data but do not go as far in buildings,
plants, or people. GHz waves only enter the surface of the skin, compared
to a centimeter or so for MHz waves. It also means that 5G GHz networks
need many smaller, lower power base stations compared to older networks. 5G
networks use different modulation, which is how the data is packaged in the
cell signal. Some scientists think that this new modulation may cause
unknown human health effects.
There are limited studies on health-related
effects of millimeter waves. The results of most studies in the literature
are of uncertain relevance to health. Many have small samples of subjects,
and many lack elementary precautions to ensure reliability. Well-done
studies to identify biological effects of millimeter waves of potential
health significance are warranted. The scientific evidence on which to base
safety recommendations is limited resulting in the two conflicting
theoretical evaluations of risk below:
Key findings of the 2020 report on Health and Safety of
5G Wireless Networks by
the IEEE Committee on Man and Radiation include:
Unlike
current MHz fields, the higher frequency GHZ signals do not penetrate
beyond the outer layers of skin and thus do not expose deeper tissues
directly.
Overall
exposure levels will not change much and will come mostly from our personal
wireless devices (as they do now).
Exposure
levels in public spaces will stay well below the limits set by scientific
experts.
So
long as exposures remain below those limits, current research does not show
that there will be any adverse thermal effects, including from 5G.
Findings from Reviews
on Environmental Health recommend more
research into the long-term effects of exposure to the higher 5G frequencies,
new modulations, and proximity to 5G base stations.
Occupational Exposure
Many
municipal and utility workers will need to work near 5G sources. Each
employer should have an exposure control plan or safety plan that outlines
the types of controls for those working near cellular stations. Controls
such as locking-out the transmitter (that is, removing the RF while work is
performed); proper training, procedures, and signage; and monitoring RF
levels while working will be key. Generation Gap
(aiha.org)
Minimize Your Risk
The American Academy of Pediatrics
(AAP) recommends limiting cell phone use for children and teenagers. The
AAP also reminds parents that cell phones are not toys and are not
recommended for infants and toddlers to play with. If you have concerns
about RF fields, the AAP offers the following easy
tips for reducing exposure:
Do not talk on the phone or text
while driving. This increases the risk of automobile crashes.
Exercise caution when using a phone
or texting while walking or performing other activities.
Use text messaging when possible and
use cell phones in speaker mode or with the use of hands-free kits.
When talking on the cell phone, try
holding it an inch or more away from your head.
Make only short or essential calls
on cell phones.
Avoid carrying your phone against
the body like in a pocket, sock, or bra.
If you plan to watch a movie on
your device, download it first, then switch to airplane mode while you
watch in order to avoid unnecessary radiation
exposure.
Keep an eye on your signal strength
(i.e. how many bars you have). The weaker your
cell signal, the harder your phone has to work and
the more radiation it gives off. It's better to wait until you have a
stronger signal before using your device.
Avoid making calls in cars,
elevators, buses. Cell phone works harder to get a signal through metal,
increasing its power.
Remember that cell phones are not
toys or teething items.
US Regulations
The Federal Communications
Commission (FCC) is required to assess the
health effects of RF from the transmitters they regulate. Groups like ANSI, IEEE, and NCRP have set RF exposure limits. In 1996, the FCC adopted
the NCRP's limits for field strength and power density from 300 kHz to 100
GHz. In addition, the FCC adopted the ANSI/IEEE specific absorption
rate (SAR) limits for devices that emit close to the body.
The FCC requires that wireless
communication devices sold in the U.S. stay within these RF exposure
limits. The FCC also licenses sites that emit RF, such as radio and
television broadcast stations. The FCC reviews such sites to make sure they
comply with the limits when those sites apply for construction, modify a
facility, or renew their license.
FCC Radiofrequency Safety
FCC Radiofrequency Guidelines
for Cellular and PCS Sites
FCC Review of RF Exposure
Policies
FDA Cell Phone Facts Questions and Answers
For more information and additional resources, contact: [email protected]
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