Maximum recommended radio frequency exposure levels
(power density) by source
the general public, the recommended maximum whole-body average radio
frequency exposure limit as measured by the incident power density
varies by source:
FCC (based on acute heating averaged over 30 minutes)
µW/m2 (for 30 - 300 MHz)
frequency (in Hz)/150 µW/m2
(for 300 MHz - 1500 MHz)
µW/m2 (for 1500 MHz - 100,000 MHz)
(based on acute heating averaged over 30 minutes)
µW/m2 (for 30 - 400 MHz)
frequency (in Hz)/200 µW/m2
(for 400 MHz - 2000 MHz)
µW/m2 (for 2000 MHz - 300,000 MHz)
Recommended level: <0.1 µW/m2
Mhz = megahertz = million cycles per second
µW/m2 = microwatts per square meter = millionths of a watt per square meter
April 19, 2022
Leading experts on wireless radiation biological effects call for stronger exposure limits in new research review
On April 19, Dr. Henry Lai and B. Blake Levitt published an extensive
review of the research on the biological effects of wireless radiation
which calls for stronger limits on radio frequency radiation exposure to
protect human health. According to their paper, governments should
adopt a maximum full-body Specific Absorption Rate (SAR) of 1.65 milliwatts per kilogram
which is 48 times lower than the wireless exposure limits that
allow the public to be exposed to a full-body SAR of 80 milliwatts per
kilogram and 960 times lower than the 1.6 watts per kilogram cell phone exposure limit for the head and body in the U.S. The paper was published in the peer-reviewed journal,
Electromagnetic Biology and Medicine (see abstract and excerpts below).
Dr. Lai is professor emeritus at the University of Washington.
In his long research career he has focused on the biological effects of
non-ionizing electromagnetic fields and their possible medical applications with research
end points covering molecular biology, neurochemistry, behavior, and
cancer treatment. He has published over 100 peer-reviewed research papers.
Henry Lai, B. Blake Levitt.
of intensity, exposure duration, and modulation on the biological
effects of radiofrequency radiation and exposure guidelines. Electromagnetic Biology and Medicine. April, 2022. doi: 10.1080/15368378.2022.2065683.
In this paper, we review the literature on three important exposure
metrics that are inadequately represented in most major radiofrequency
radiation (RFR) exposure guidelines today: intensity, exposure duration,
and signal modulation. Exposure intensity produces unpredictable
effects as demonstrated by nonlinear effects. This is most likely caused
by the biological system’s ability to adjust and compensate but could
lead to eventual biomic breakdown after prolonged exposure. A review of
112 low-intensity studies reveals that biological effects of RFR could
occur at a median specific absorption rate of 0.0165 W/kg. Intensity and
exposure duration interact since the dose of energy absorbed is the
product of intensity and time. The result is that RFR behaves like a
biological “stressor” capable of affecting numerous living systems. In
addition to intensity and duration, man-made RFR is generally modulated
to allow information to be encrypted. The effects of modulation on
biological functions are not well understood. Four types of modulation
outcomes are discussed. In addition, it is invalid to make direct
comparisons between thermal energy and radiofrequency electromagnetic
energy. Research data indicate that electromagnetic energy is more
biologically potent in causing effects than thermal changes. The two
likely function through different mechanisms. As such, any current RFR
exposure guidelines based on acute continuous-wave exposure are
inadequate for health protection.
"Over the last 25–30 years, significant information has been published
that in other regulated areas would have resulted in re-examination and
adjustments to allowable exposure limits. This has not been the case
with these two groups [the FCC and ICNIRP] which adhere to a model based on obsolete
scientific evidence, especially in light of the new 5G network that uses
higher frequencies and novel modulation forms that have never been used
before in broad civilian telecommunications and which are poorly
"RFR effects have been observed at low intensities (< 0.4 W/kg) – a
list of which is included in Supplement 1 – far below the guidelines.
This points to both the nonlinearity of how living systems couple with
nonionizing radiation as well as the inadequacy of acute thresholds. The
studies encompass many different biological effects to myriad systems,
including: apoptosis induction, adrenal gland activity, blood–brain
barrier permeability, brain transmitter levels, calcium concentration in
heart muscle, calcium efflux, calcium movement in cells, cell growth,
cognitive functions, cellular damage in liver, decreased cell
proliferation, embryonic development, endocrine changes, enolose
activity, genetic effects, hippocampal neuronal damage, immunological
functions, kidney development, memory functions, latency of muscular
contraction, membrane chemistry, nerve cell damage, metabolic changes,
neural electrical activity, oxidative stress, plant growth, prion level,
protein changes, renal injury, serum testosterone concentration,
heat-shock protein induction, testis morphology, testosterone synthesis,
thymidine incorporation, and ultrastructural alteration in cell
cytoplasm. In fact, there are not many physiological functions in
humans, animals, or plants that are not affected by low-level RFR."
"As reflected in Supplement 1, SARs at which effects were observed were available from 112 studies. Of these, 75 (67%) were in vivo exposure studies with whole body/organ SARs available. The other 37 (33%) studies were in vitro experiments.... The level at which biological effects occur represents data from in vivo and in vitro
and acute and chronic/repeated-exposure experiments. There is a very
wide range of effects seen. With an exposure that induces a SAR of
0.0165 W/kg, and using a ten-fold protection, the SAR would be
0.00165 W/kg (i.e., 1.65 mW/kg). For rate of energy absorption in body
organs, 0.00165 W/kg is far below the maximum level allowed in the
guidelines (whether over 1 or 10 gm of tissue as per FCC/ICNIRP
allowances). Given the large body of work as illustrated in Supplement
1, the SAR at, or below, 4 W/kg as a safe threshold is insupportable."
"The duration of exposure is another important factor in
biological effects. Other than demarcations for whole body exposures
averaged over 30 minutes and local body areas averaged over 6 minutes,
neither FCC nor ICNIRP address duration, especially pertaining to
long-term and low-level RFR exposures. These are prevalent in both
near-field exposures to people with WiFi routers, for example, as well
as cell phones, and far-field exposures from infrastructure that have
created chronic rising ambient background levels (Levitt et al. 2021a).
The guidelines are written only for short-term acute durations.... What
we do know is that the supposition that all exposures are the same above
and below the SAR threshold set by FCC/ICNIRP is fundamentally flawed
in light of the most current research. One feasible and logical
solution to such uncertainties regarding duration as an exposure factor
would be to adopt an SAR level commensurate with the studies summarized
in Supplement 1 at no higher than 0.00165 W/kg, no matter the exposure
"It is generally believed that modulated
RFR is more biologically active than continuous-wave (CW) radiation,
i.e., the carrier-wave. To understand the biological and possible
hazardous health effects of RFR, it is therefore important to understand
modulation effects. Below we discuss what is known about modulation
from the research literature (mostly from 1990 to date) and examine the
claim that modulation makes RFR more biologically significant...There is
research showing no significant biological effects of CW-RFR (Table 1a)
but there are also studies that reported CW-RFR effects too (Table 1b).
The reason why CW-RFR produced effects in some studies but not others
is unknown. Both types of studies (with “effect” and “no effect”
outcomes) involved many different biological endpoints, exposure
intensities, and duration of exposure – with no discernible differences.
A possible explanation is that different tissue types respond
differently to CW-RFR. But that just adds another level of inquiry. One
of the most puzzling observations is when CW caused an effect but
modulation did not (e.g., Kubinyi et al. 1996; Luukkonen et al. 2009).
In some studies, a modulated field produced an effect that was not
produced by CW. These observations may indicate that the CW carrier-wave
itself and modulation act on different mechanisms....
Differences in responses between CW and modulated fields of the same
frequency and incident power density provide strong proof that
non-thermal effects occur since the two conditions should produce the
same amount of heating....
Some studies reported that different frequencies of modulation caused
different biological responses
CW and modulated fields can cause the same effects but with different
degrees of biological activity and intensity of reactions. In most
instances, a modulated field was found to be more potent than CW versus
only one study in which the opposite was reported (Persson et al.
To add to the complexities described above, effects with modulated
fields have also been shown to depend on exposure duration....
there are many studies that used intermittent exposure (e.g., 10 min
ON/10 min OFF) instead of continuous exposure with the supposition that
intermittent exposure is more biologically active. But not much data
showed this to be true....
There are many studies using pulsed fields (i.e., mobile phone signals
are pulsed), but there are not many studies that compared pulsed and CW
fields of the same SAR in the same study. However, there are reports
that effects only occurred with a pulsed field but not CW....
there are many studies showing effects of RFR on the hippocampus..."
changes and stress have been reported in many papers on exposure to
electromagnetic fields (Lai 2020; Yakymenko et al. 2016). These are the
most consistent cellular responses to RFR exposure. Mechanisms have been
proposed to account for oxidative effects that may involve the
low-frequency component of modulation (e.g., see Barnes and Greenebaum
2015; Castello et al. 2021). ... But there is not enough data to
conclude that modulation effects are caused by oxidative processes. In
fact some effects of CW exposure alone also found changes in free
"It is important to point out as significant proof of non-thermal RFR
effects that CW and modulated-waves of the same frequency and incident
power density can/and do produce different effects. The bottom line is
that certainty is elusive regarding precise effects in all
circumstances. What is clear is that both modulation and continuous-wave
RFR are biologically active and both should be considered in exposure
guidelines. In situations where enough evidence exists to warrant
specific caution, such as with pulsed fields used in cell phones and
phased modulation with 5G, particular attention should be paid to
include modulation in the guidelines beyond the suppositions of safety
contained within the safety allowances. Peak exposures must also be
factored in and not just the averaged values which only hide their
"It is apparent that the biological outcome of changing the intensity
and duration of RFR exposure is basically unpredictable. This is mainly
due to the complex nature of the biological system studied. Intensity
and duration can interact and produce different response patterns as
shown in the literature reviewed above.
It is also apparent that
how RFR modulation affects biological functions is difficult to
quantify. Observed effects are multi-variant and involve many factors
such as intensity, carrier frequencies and modulation, the modulation
waveform itself, exposure duration, and properties of the exposed
object. Not enough research data are presently available to provide an
explanation or prediction of modulation effects under all circumstances.
It may also turn out that modulation is of little major health concern
or conversely that it is the only factor that matters – evidence is thus
far too contradictory regarding modulation’s ability to consistently
enhance the biological effects of carrier-waves. Then again, with most
modulation forms the carrier-wave is completely altered. All of this
awaits proper investigation with comparison studies. In the meantime,
there are legitimate reasons for concern, given the contradictions in the
In general, anthropogenic RFR – with highly
unusual waveform characteristics and intensities that do not exist in
the natural world – is new to the environment and thus has not been a
factor in the evolution of species. Living organisms evolved over
millions of years in the presence of static and extremely-low frequency
(ELF) electromagnetic fields. These fields play critical roles in their
survival, e.g., in migration, food foraging, and reproduction, etc. (see
Levitt et al. 2021b). Living organisms are extremely sensitive to the
presence of these environmental fields and thus, they can easily be
disturbed by man-made EMF. RFR probably acts upon and modifies these
primordial EMFs and affects biological functions. Interactions of
static/ELF EMF and RFR are basically not well studied, not to mention
the mechanisms of involvement of RFR modulations. The interactions are
inevitably complex. Such interaction studies would provide answers to
Regarding the perennial thermal- versus non-thermal- effects criticism
inherent in human RFR exposure guidelines, it must be said that the
underlying mechanisms of effects should not be a matter of concern in setting of exposure guidelines as is common today. What is important is the level at which energy absorption causes an effect.
One such powerful proof – among so very many others – of non-thermal
effects is evidenced in the fact that CW and modulated-waves of the same
frequency and incident power density can produce different effects, as
seen in the modulation section of this paper and Table 2."
"When effects continue to be observed over a long period of time that go
against prevailing beliefs, even when mechanisms remain imperfectly
understood, the appropriate course of regulatory action is to examine
the underlying basis upon which an original premise was formed. When
proven incomplete or invalid by new information, the change in a
regulatory course is not only justified but is imperative. Disproven or
incomplete deductions of how RFR affects living cells and tissues, as
well as suppositions of safety for exposed individuals and the
environment are insupportable given the wealth of studies to draw from
today that have filled in many gaps. We need to more responsibly address
the increasing near- and far-field RFR exposures of contemporary life
with an eye toward 5G technology’s unique characteristics. A new
conceptual framework is called for."
Study: Wireless radiation exposure for children should be hundreds of times lower than current federal limits
Environmental Working Group, July 2021
WASHINGTON – A peer-reviewed study by
the Environmental Working Group
recommends stringent health-based exposure standards for both children
and adults for radiofrequency radiation emitted from wireless devices.
EWG’s children’s guideline is the first of its kind and fills a gap left
by federal regulators.
The study, published in the
journal Environmental Health, relies on the methodology developed by
the Environmental Protection Agency to assess human health risks arising
from toxic chemical exposures. EWG scientists
have applied the same methods to radiofrequency radiation from wireless
devices, including cellphones and tablets.
EWG recommends the Federal
Communications Commission, or FCC, adjust its woefully outdated health
standards for wireless radiation, last revised a quarter-century ago,
well before wireless devices became ubiquitous,
heavily used appliances synonymous with modern life. The recommendation
draws on data from a landmark 2018 study from the National Toxicology
Program, or NTP, one
of the largest long-term studies on the health effects of radiofrequency radiation exposure.
EWG’s new guidelines, the
first developed in the U.S. to focus on children’s health, recommend
that children’s exposure overall be 200 to 400 lower than the whole-body
exposure limit set by the FCC in 1996.
The EWG recommended limit
for so-called whole-body Specific Absorption Rate, or SAR, for children
is 0.2 to 0.4 milliwatts per kilogram, or mW/kg. For adults, EWG
recommends a whole-body SAR limit of 2 to 4 mW/kg,
which is 20 to 40 times lower than the federal limit.
The FCC has not set a
separate standard for children. Its standards for radiofrequency
radiation set a maximum SAR of 0.08 watts per kilogram, or W/kg, for
whole-body exposure and an SAR for localized spatial peak
– the highest exposure level for a specific part of the body, such as
the brain – of 1.6 W/kg for the general population.
The NTP studies examined the health effects of 2G and 3G wireless radiation and found there is “clear
evidence” of a link between exposure to radiofrequency radiation and heart tumors in laboratory animals. Similar results were reported
by a team of Italian scientists from the Ramazzini Institute.
Cellphone radiation was classified a “possible
carcinogen” in 2011 by the International Agency for
Research on Cancer, part of the World Health Organization, a conclusion
based on human epidemiological studies that found an increased risk of
glioma, a malignant brain cancer, associated
with cellphone use.
EWG scientists say that
more research is needed on the health impacts of the latest generation
of communication technologies, such as 5G. In the meantime, EWG’s
recommendation for strict, lower exposure limits for
all radiofrequency sources, especially for children.
When the FCC established
its radiofrequency radiation limits, following the passage of the 1996
Telecommunications Act, relatively few Americans, and likely no
children, owned and used cellphones.
Much has changed since the federal limits were set, including technology and how these devices are used. A survey completed
by the nonprofit Common Sense Media in March 2020, just before the
start of the Covid-19 spread in the U.S., found that 46 percent of 2- to
4-year-olds, and 67 percent of 5- to 8-year-olds, had their own mobile
devices, such as a tablet or smartphone.
With remote learning, a
necessity during the Covid-19 pandemic, phones, tablets and other
wireless devices became a part of life for young children, tweens and
“The FCC must consider the
latest scientific research, which shows that radiation from these
devices can affect health, especially for children,” said Uloma
Uche, Ph.D., EWG environmental health science fellow and lead author of the study.
“It has been 25 years since
the FCC set its limits for radiofrequency radiation. With multiple
sources of radiofrequency radiation in the everyday environment,
including Wi-Fi, wireless devices and cell towers, protecting
children’s health from wireless radiation exposures should be a
priority for the FCC,” she added.
“We have grave concerns
over the outdated approach the federal government has relied on to study
the health effects of cellphone radiation and set its current safety
limit and advice for consumers,” said EWG President Ken
Cook. “Government guidelines are a quarter-century old
and were established at a time when wireless devices were not a constant
feature of the lives of nearly every American, including children.”
Reviewing 5G and other
aspects of wireless technology should be the focus of public health
agencies, noted Cook. “It is long past time the federal government made
exposure to 5G wireless devices safe. We strongly
believe those exposures deserve far more investigation and scientific
rigor than has been applied to date.”
“The evidence shows that
children absorb more radiofrequency radiation than adults, and the
developing body of a child is more vulnerable to such effects,” said Olga
Naidenko, Ph.D., EWG’s vice president for science investigations and co-author of the study.
“More research on the
safety and sustainability of wireless technology is essential,” added
Naidenko. “Meanwhile, there are simple steps everyone can take to
protect their health, such as keeping wireless devices
farther from their bodies.”
There are a number of easy,
precautionary steps consumers can take until the government conducts
the rigorous scientific assessment the issue deserves, which should have
occurred years ago.
“Based on our review of the
health risks and the inadequacy of current standards to protect
children, while the science evolves, it is perfectly reasonable for
parents to consider minimizing or eliminating radiofrequency
radiation sources at home by relying more on wired internet access, and
to urge schools to take comparable steps to reduce classroom and campus
exposure,” said Cook.
tips for consumers who want to reduce radiofrequency radiation from
wireless devices include using a headset or speaker, texting instead of
talking, and limiting the time children spend on
Find all of EWG’s tips to reduce exposure to wireless radiation here.
EWG’s recommendation for
limits for radiofrequency radiation exposure is its latest effort to
advance the public dialogue about science-based standards that protect
Development of health-based exposure limits
for radiofrequency radiation from wireless devices using a benchmark
Uloma Igara Uche,
Olga V Naidenko. Development of health-based exposure limits for
radiofrequency radiation from wireless devices using a benchmark dose
approach. Environ Health 20, 84 (2021). doi: 10.1186/s12940-021-00768-1.
studies and research on laboratory animals link radiofrequency
radiation (RFR) with impacts on the heart, brain, and other organs. Data
from the large-scale animal studies conducted by the U.S. National
Toxicology Program (NTP) and the Ramazzini Institute support the need
for updated health-based guidelines for general population RFR exposure.
development of RFR exposure limits expressed in whole-body Specific
Absorption Rate (SAR), a metric of RFR energy absorbed by biological
Methods Using frequentist and Bayesian averaging
modeling of non-neoplastic lesion incidence data from the NTP study, we
calculated the benchmark doses (BMD) that elicited a 10% response above
background (BMD10) and the lower confidence limits on the BMD at 10%
extra risk (BMDL10). Incidence data for individual neoplasms and
combined tumor incidence were modeled for 5% and 10% response above
and increased risk of neoplasms in male rats were the most sensitive
health outcomes following RFR exposures at 900 MHz frequency with Code
Division Multiple Access (CDMA) and Global System for Mobile
Communications (GSM) modulations. BMDL10 for all sites cardiomyopathy in
male rats following 19 weeks of exposure, calculated with Bayesian
model averaging, corresponded to 0.27–0.42 W/kg whole-body SAR for CDMA
and 0.20–0.29 W/kg for GSM modulation. BMDL10 for right ventricle
cardiomyopathy in female rats following 2 years of exposure corresponded
to 2.7–5.16 W/kg whole-body SAR for CDMA and 1.91–2.18 W/kg for GSM
modulation. For multi-site tumor modeling using the multistage cancer
model with a 5% extra risk, BMDL5 in male rats corresponded to 0.31 W/kg
for CDMA and 0.21 W/kg for GSM modulation.
range of 0.2—0.4 W/kg for all sites cardiomyopathy in male rats was
selected as a point of departure. Applying two ten-fold safety factors
for interspecies and intraspecies variability, we derived a whole-body
SAR limit of 2 to 4 mW/kg, an exposure level that is 20–40-fold lower
than the legally permissible level of 0.08 W/kg for whole-body SAR under
the current U.S. regulations. Use of an additional ten-fold children’s
health safety factor points to a whole-body SAR limit of 0.2–0.4 mW/kg
for young children.
Study: Wireless radiation exposure for children should be hundreds of times lower than federal limits (based on NTP study)
ICNIRP’s Exposure Guidelines for Radio Frequency Fields
Worldwide Radio Frequency Radiation Exposure Limits versus Health Effects