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TYPE Perspective
PUBLISHED 31 October 2022
DOI 10.3389/fpubh.2022.1042478
OPEN ACCESS
EDITED BY
Dariusz Leszczynski,
University of Helsinki, Finland
REVIEWED BY
Hamed Jalilian,
University College Dublin, Ireland
Michael Kundi,
Medical University of Vienna, Austria
*CORRESPONDENCE
James C. Lin
lin@uic.edu
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This article was submitted to
Radiation and Health,
a section of the journal
Frontiers in Public Health
RECEIVED 12 September 2022
ACCEPTED 17 October 2022
PUBLISHED 31 October 2022
CITATION
Lin JC (2022) Carcinogenesis from
chronic exposure to radio-frequency
radiation.
Front. Public Health 10:1042478.
doi: 10.3389/fpubh.2022.1042478
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Carcinogenesis from chronic
exposure to radio-frequency
radiation
James C. Lin*
Departments of Electrical and Computer Engineering, Bioengineering, and Physiology and
Biophysics, University of Illinois Chicago, Chicago, IL, United States
The past two decades have seen exponential growth in demand for wireless
access that has been projected to continue for years to come. Meeting the
demand would necessarily bring about greater human exposure to microwave
and radiofrequency (RF) radiation. Our knowledge regarding its health eects
has increased. Nevertheless, they have become a focal point of current interest
and concern. The cellphone and allied wireless communication technologies
have demonstrated their direct benefit to people in modern society. However,
as for their impact on the radiation health and safety of humans who are
unnecessarily subjected to various levels of RF exposure over prolonged
durations or even over their lifetime, the jury is still out. Furthermore, there are
consistent indications from epidemiological studies and animal investigations
that RF exposure is probably carcinogenic to humans. The principle of
ALARA—as low as reasonably achievable—ought to be adopted as a strategy
for RF health and safety protection.
KEYWORDS
wireless and mobile technology, exposure safety and regulations, cancer risk,
human-agent interaction, animal experiment, ALARA (as low as reasonably achievable)
Introduction
Microwave and radiofrequency (RF) radiations power all over-the-air wireless
channels, communication links, and network systems through which text, files, images,
and videos are transferred by mobile devices and related platforms. The recent decades
have seen exponential expansion in popularity for mobile access that has been forecasted
to persist in the foreseeable future. Satisfying the demand would necessarily bring about
greater human exposure to microwave and RF radiation.
Asides from primary intended roles as a carrier or infrastructure that enables the
communication technology, microwave and RF radiation may induce additional effects
that could influence the vital functions of living organisms. The biological changes caused
would manifest in multiple physical and biological spheres. They may or may not be
grossly apparent or observable soon after exposure of the living organisms. In some
cases, they may only manifest until years later—they may develop years to decades after
repeated low-level exposures.
The health impact of RF and microwave radiations has been a subject of scientific
investigation shortly after demonstration of their production in scientific laboratories,
over a century ago (1,2). Without any doubt, their use especially in cellular mobile
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Lin 10.3389/fpubh.2022.1042478
communication and associated wireless technologies have
enriched human lives. Our knowledge regarding its health effects
has increased gradually. Nonetheless, RF radiation has come to
be a focal point of interest as a result of accelerated use of RF and
microwave radiation in wireless mobile communications.
The WHO’s International Agency for Research on Cancer
(IARC) categorized exposure to RF and microwaves as a possible
carcinogen to humans in 2011. The IARC had evaluated existing
scientific studies and came to the conclusion that while data
was imperfect and restricted, particularly regarding reports from
animal experiments, epidemiological investigations concerning
elevated risks for gliomas (a type of malignant brain cancer)
and acoustic neuromas (a non-malignant tumor of the acoustic
or vestibulocochlear nerves) among heavy users or long-term
customers of cellphones, are satisfactorily robust to warrant a
classification of possibly carcinogenic in humans for exposure to
RF and microwave radiation (3,4).
Recently, two commonly distributed RF health protection
recommendations revised their guidelines and standards.
The updated International Commission on Nonionizing
Radiation Protection guidelines (5) and Institute of Electrical
and Electronic Engineers International Committee on
Electromagnetic Safety standards (6) are strongly connected to
acute temperature rises induced by RF heating inside the human
body. The updated safety guidelines and standards showed
without any question the groups’ staunch convictions of nothing
but heat to worry about with microwave and RF radiation.
A persistent and vexing question lingers concerning these
guidelines and standards for safe long-term exposure to
RF radiation (in contrast to exposures shorter than 6 or
30 min). A general sense on the absence of appreciation of
scientific evidence regarding long-term exposure below the basic
restrictions continues with these safety guidelines and standards.
There is also the question of how there can be such divergent
evaluations and inferences of the identical scientific findings
by WHO’s IARC, ICES, and ICNIRP. To be fair, scientists
are not impervious to conflicts of interest such as conflicting
financial interests or personal relations which could affect
the deliberations and reporting through such experiences as
groupthink. Also, in some ways, it may parallel the compulsion
by big business to choose profit over societal concerns—big
businesses often use a range of organized and refined tactics to
enhance and protect their commercial interests, and regrettably
in some cases these tactics come at the expense of public health.
Human beings repeatedly render decisions and select
choices that challenge principled logic. Indeed, science has
not been devoid of politics—weird as that may sound.
Various biases can impair sensible reasoning and result in bad
judgments. Groupthink can mislead human beings and inhibit
scientists from making understandable inferences. Regrettably,
groupthink or herd mentality is as rampant today as ever. Has
science become partisan? And if science becomes partisan, is
it science or politics, or would it be political science? At times,
science gets wrapped up in politics and politics intervenes with
science. It may simply turn out to be a matter of guilelessly
being politically correct of the willing. Less than rigorous
enforcement of policies in research conduct or full disclosure of
financial conflicts can lead to failures in guiding and informing
the development of transparent and trustworthy evaluations
of scientific evidence for safety protection. Scientists may not
always be consistent, coherent, or as transparent as promoted.
Carcinogenicity in rats exposed
lifelong to RF radiation
Briefly, through 2016, counting all carcinogenicity
and co-carcinogenicity investigations in laboratory rats
experimentally exposed life-long or for a minimum of 2
years to cellphone-type RF radiation, there were 9 reported
studies revealing important modification in incidence of
cancer rates between RF- and sham-exposures (7). The RF
exposures involved frequencies ranging from 836 to 2,450
MHz and used common wireless mobile-phone modulations
and telecommunication protocols. In summary, there were
more reported results showing no cancer-causing responses
than showing cancer effects, regardless of the study design,
merit, flaws, experimental quality, shortcomings, limitations,
or methodological weaknesses. Note that many investigations
were performed by restraining the animals during exposure,
which included the observation of an apparent protective
(tumor-inhibiting) response. Restraining a rodent causes
stress for the animal and the stress response interferes with
neoplastic development (8,9). Furthermore, most of them are
one-of-a-kind investigations—few studies were conducted as
an extant, independent replication or confirmation. The study
reports have been inconsistent and fraught with omissions of
experimental details in some cases. Thus, it is challenging to
make an unequivocal conclusion. A remarkable flaw was that
many of the reported projects did not involve concurrent or
cage-control animals as part of the experimental protocol, or
relevant data were not included in the statistical analyses.
Whether RF exposure from wireless and mobile devices and
systems poses a personal health risk has been a vexing question
for some time. The answer has been equivocal and controversial.
The effect of RF exposure on carcinogenicity thus remained
tentative, as noted in the IARC report. The inconsistencies
and ambiguities present uncertainties to estimation of risks of
exposure to RF radiation from cellphones to public health.
Recent results from laboratory rat
experiments
It is noteworthy that the results from animal experiments
that were coveted by IARC at the time of its classification were
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supplied by the National Toxicology Program (NTP) of the U.S.
National Institute of Environmental Health Science (NIEHS)
in 2018. Specifically, NTP/NIEHS presented the findings of
two types of cancers in laboratory rats exposed, lifelong, to RF
radiation that were commonly used for 2G and 3G cellphone
operations (10,11). The study was the largest animal health
effect study taken upon by NTP/NIEHS in its history, including
the large number of toxic chemical agents. The results showed,
among other findings, there was statistically significant and clear
evidence (compared to concurrent controls) that exposure to
cellphone RF radiation had caused the observation of malignant
cardiac schwannoma (a rare form of tumor) in male rats
whose RF-induced body temperature elevation was up to 1◦C.
Furthermore, the same schwannoma risk was indicated among
female rats. NTP also reported unusual patterns of damage
to heart tissue (cardiomyopathy) in both RF-exposed males
and females when compared with concurrent control rats.
Based on statistical significance, the outcome of pathological
examinations showed some signs of RF-dependent cancer-
causing activity in the male-rat brains, malignant gliomas in
particular. Outcomes for females were regarded as ambiguous
for gliomas compared to concurrent controls.
Moreover, results from extensive research of carcinogenesis
in rats exposed to 3G, 1800-MHz RF radiation performed by
Ramazzini Institute’s Cesare Maltoni Cancer Research Center in
Bologna, Italy was published soon after the NTP/NIEHS report
(12). The investigation involved whole-body exposure of male
and female rats, either prenatal until death or lifelong, under
far zone plane-wave exposure conditions. During the 19-h per
day exposures for ∼2 years, the whole-body SARs were 0.001,
0.03, and 0.1 W/kg. A statistically significant rise was observed
for cardiac schwannomas incidents in males for whole-body RF
exposure at 0.1 W/kg. It is noteworthy that the NTP/NIEHS
and Ramazzini RF exposure research showed comparable
findings of cardiac schwannomas and cerebral gliomas. Thus,
two comparatively well-conducted animal investigations using
the same strain of rats demonstrated consistent outcomes in
significantly elevated cancer risks.
Safety protection guidelines and
standards
While recognizing that the two recent large animal studies
employed good-laboratory practices (GLP), and prolonged
exposures of rats for their entire lifespan, the current revisions
of safety protection guidelines and standards decided to nitpick
with objections based on “chance differences” and exposed rat
core-body temperatures of up to 1◦C at 0.1 W/kg. Oddly,
in choosing to do so, ICES (6) and ICNIRP (5) neglected
the incongruity of suggesting a 1◦C body-core temperature
elevation as the putative cancer-causing agent. Furthermore, the
recommendations overlooked entirely the consequences of RF
exposures (the independent variable for the animal experiments)
or preferred evading the implications through pretenses which
may be paraphrased as “the evidence or findings do not provide
credible indication of adverse effects caused by chronic RF
exposures” ICES (6) and ICNIRP (5). These same groups
proceeded to use ambiguous expressions such as “substantial
limitations” to assert the motives in barring any “conclusions
being drawn concerning RF EMFs and carcinogenesis,” to
defend the revised RF safety protection guidelines and standards.
Evidently, the revisions were predicated on the groups’ strong
convictions of nothing but heat to worry about with microwave
and RF radiation.
Moreover, it opined that although epidemiological studies of
RF radiation associated with cellphone use and cancer risk have
been performed, reported results from research on increased
acoustic neuroma, brain gliomas, meningioma, and parotid
gland tumors have not provided sufficient evidence of greater
cancer risk. The recently revised safety guidelines and standards
also noted that while somewhat elevated odds ratios were
observed, there are inconsistencies and limitations such as recall
or selection bias which preclude the epidemiological results
from being considered for recommending exposure guidelines
and standards. The predilection to reject and disparage positive
outcomes, and affection for and eagerness to accept negative
conclusions, all at once, are palpable and concerning.
Discussion and conclusion
The recently revised ICES standards and ICNIRP safety
guidelines make recommendations to supposedly guard against
known hazardous health consequences in humans resulting
from exposure to RF frequencies up to 300 GHz. The guidelines
and standards are for short-term exposures of 6–30 min, based
on limiting whole-body temperature from increasing above 1◦C
or local tissue temperature to 5◦C (5,6). The updated safety
guidelines and standards demonstrate without any doubt the
groups’ strong convictions on nothing but heat to worry about
with RF radiation.
If the groups that promulgate the safety protection
recommendations assume what seems to be their stance
regarding experimental results in rats by U.S. NTP/NIEHS that
a whole-body temperature increase of 1◦C causes cancer, then
the safety or reduction factors of 50 recommended for the
general population, or 10 for occupationally engaged working
person would be borderline for the specified objective and
practically worthless from the standpoint of protecting “safety.”
It is noteworthy that the highest SAR or exposure level chosen
by NTP/NIEHS that showed increased carcinogenicity in rats is
essentially the same as that chosen by ICES and ICNIRP for their
basic restrictions.
The fact is that the missing pieces according to IARC
(4), or the previously coveted experimental animal data (7) as
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Lin 10.3389/fpubh.2022.1042478
currently provided by NTP/NIEHS (10) and Ramazzini Institute
(12) complement IARC’s evaluation of human epidemiological
studies in support of its classification of RF radiation as a
possible carcinogen. It gives rise to the plausibility for IARC to
enhance its previous, mostly epidemiology-based classification
to the higher level of “probably cancer causing” for RF exposure.
Furthermore, more recent systematic reviews and meta-
analyses of the case-control research on mobile phone use have
reported statistically significant increases in brain tumor risk
associated with 1,000 or more hours of cellphone use, or about
17 min per day over 10 years (13,14).
Off-the-shelf cellphones have SAR ranging from 0.2 and
0.5 W/kg (15). The U.S. Federal Communications Commission
(FCC) rules require that they do not exceed the SAR limit
of 1.6 W/kg for cellphones operating at its highest possible
power level. Clearly, cellphones are operating at a fraction of
the SAR acceptable to FCC and they are well below (e.g.,
only 10%) the 2.0 W/kg promulgated by ICES and ICNIRP.
It is meaningful to mention that presently allowable power for
cellphones are roughly 5 orders of magnitude higher than a
prototype cellphone consuming 3.5 µW of power to enable
voice calls by harvested ambient RF power (16). It is conceivable
that upcoming developments would enable cellphone functions
including data transmission via energy harvesting. Obviously, it
stays important to be attentive so that the supporting ambient
RF radiation will not create a cause of safety and health concern.
The simple and effective public health notion of “An
ounce of prevention is better than a pound of cure” may
conjure up old fashioned. It may arouse intense reactions, with
enormous defiance especially from individuals who may be
beneficiary of modern promotions. The cellphone and allied
wireless communication technologies have shown their direct
benefit to people in modern society. However, as for their
impact on the radiation health and safety of humans who
are subjected unnecessarily to various levels of RF exposure
over prolonged durations or even over their lifetime, the
jury is still out. Furthermore, there are consistent indications
from epidemiological studies and animal investigations that
RF exposure is, at least, probably carcinogenic to humans.
The principle of ALARA—as low as reasonably achievable—
ought to be adopted as a strategy for RF health and
safety protection.
Data availability statement
The original contributions presented in the study are
included in the article/supplementary material, further inquiries
can be directed to the corresponding authors.
Author contributions
The author confirms being the sole contributor of this work
and has approved it for publication.
Funding
This work was supported by DSC-08034011324PRD.
Conflict of interest
The author declares that the research was conducted in the
absence of any commercial or financial relationships that could
be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the
authors and do not necessarily represent those of their affiliated
organizations, or those of the publisher, the editors and the
reviewers. Any product that may be evaluated in this article, or
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References
1. Schwan HP. Electrical properties of tissue and cell suspensions. Adv Biol Med
Phys. (1957) 5:147–209. doi: 10.1016/B978-1-4832-3111-2.50008-0
2. Schwan HP. Early history of bioelectromagnetics. Bioelectromagnetics. (1992)
13:453–67. doi: 10.1002/bem.2250130604
3. Baan R, Grosse Y, Lauby-Secretan B, El Ghissassi F, Bouvard V, Benbrahim-
Tallaa L, et al. Carcinogenicity of radiofrequency electromagnetic fields. Lancet
Oncol. (2011) 12:624–6. doi: 10.1016/S1470-2045(11)70147-4
4. IARC. Working group on the evaluation of carcinogenic risks to humans non-
ionizing radiation, Part 2: radiofrequency electromagnetic fields. IARC Monogr
Eval. Carcinog Risks Hum. (2013) 102:1–460.
5. ICNIRP. Guidelines for limiting exposure to electromagnetic fields (100 kHz to
300 GHz). Health Phys. (2020) 118:483–524. doi: 10.1097/HP.0000000000001210
6. ICES. IEEE Standard for Safety Levels With Respect to Human Exposure to
Electric, Magnetic, and Electromagnetic Fields, 0Hz to 300 GHz," (Revision of IEEE
Std C95.1-2005/ Incorporates IEEE Std C95.1-2019/Cor 1-2019). (2019). p. 1–312.
7. Lin JC. Cancer occurrences in laboratory rats from exposure
to rf and microwave radiation. IEEE J Electromagnet. (2017) 1,
2–13. doi: 10.1109/JERM.2017.2721427
8. Frick LR, Arcos ML, Rapanelli M, Zappia MP, Brocco M, Mongini
C, et al. Chronic restraint stress impairs T-cell immunity and promotes
tumor progression in mice. Stress. (2012) 12:134–43. doi: 10.1080/102538908021
37437
9. Feng Z, Lianxin Liu L, Zhang C, Zheng T, Wang J, Lin M, et al. Chronic
restraint stress attenuates p53 function and promotes tumorigenesis. PNAS. (2009)
109:7013–8. doi: 10.1073/pnas.1203930109
Frontiers in Public Health 04 frontiersin.org
Lin 10.3389/fpubh.2022.1042478
10. NTP/NIEHS. Technical Report on the Toxicology and Carcinogenesis Studies
in HSD: Sprague–Dawley SD rats Exposed to Whole-Body Radio Frequency
Radiation at a Frequency (900 MHz) and Modulations (GSM and CDMA) Used by
Cell Phones, NTP Tech. Rep. 595, Raleigh, NC (2019).
11. Wyde ME, Horn TL, Capstick MH, Ladbury JM, Koepke G, Wilson
PF, et al. Effect of cell phone radiofrequency radiation on body temperature
in rodents: pilot studies of the National Toxicology Program’s reverberation
chamber exposure system. Bioelectromagnetics. (2018) 39:190–9. doi: 10.1002/bem.
22116
12. Falcioni L, Bua L, Tibaldi E, Lauriola M, De Angelis L, Gnudi F, et al.
Report of final results regarding brain and heart tumors in Sprague-Dawley rats
exposed from prenatal life until natural death to mobile phone radiofrequency field
representative of a 1.8 GHz GSM base station environmental emission. Environ Res.
(2018) 165:496–503. doi: 10.1016/j.envres.2018.01.037
13. Myung SK, Ju W, McDonnell DD, Lee YJ, Kazinets G,
Cheng CT, et al. Mobile phone use and risk of tumors: a meta-
analysis. J Clin Oncol. (2009) 27:5565–72. doi: 10.1200/J.C.O.2008.21.6
366
14. Choi YJ, Moskowitz JM, Myung SK, Lee YR, Hong YC. Cellular
phone use and risk of tumors: systematic review and meta-analysis. Int
J Environ Res Public Health. (2020) 17:8079. doi: 10.3390/ijerph17218
079
15. EMF Academy. Lowest Radiation Cell Phones of 2022. (2022). Available
online at: https://emfacademy.com/lowest-radiation- cell-phones/ (access in
September 2022).
16. Talla V, Kellogg B, Gollakota S, Smith JR. Battery-free cell phone.
Proc ACM Interact. Mobile, Wearable Ubiquitous Technol. (2017). p. 1–
2. doi: 10.1145/3090090
Frontiers in Public Health 05 frontiersin.org
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