Monday, August 25, 2025

Electromagnetic fields threaten wildlife

(See the end of this post for additional resources.)


Combined effects of constant temperature and radio frequency exposure 
on Aedes mosquito development

Dom NC, Dapari R, Halim NMHNA, Rahman ATA. Combined effects of constant temperature and radio frequency exposure on Aedes mosquito development. Sci Rep. 2025 Aug 20;15(1):30571. doi: 10.1038/s41598-025-09383-3. 

Abstract

Mosquito-borne diseases, such as dengue, Zika, and chikungunya, pose significant public health threats, particularly in tropical regions like Malaysia. Aedes aegypti and Aedes albopictus are primary vectors of these diseases, with their developmental stages being highly sensitive to environmental factors. While temperature is a well-known driver of mosquito biology, the potential influence of anthropogenic factors such as radio frequency (RF) exposure remains underexplored. This study investigates the combined effects of temperature and RF exposure on the developmental stages of these mosquito species to provide insights into their population dynamics and inform vector control strategies. A factorial experimental design was employed, incorporating four temperature conditions (20 °C, 25 °C, 30 °C, and 35 °C) and three RF exposure levels (900 MHz, 18 GHz, and a control group with no RF exposure). The developmental durations for hatching, larval, pupation, and adult emergence stages were monitored daily under controlled laboratory conditions. Data were analyzed using a quadratic response surface model to evaluate the main effects and interactions between temperature and RF exposure. Temperature emerged as the dominant factor influencing developmental durations, with optimal conditions observed at 30-32 °C. RF exposure, particularly at 18 GHz, acted as a secondary modulating factor, accelerating developmental stages under certain temperature conditions. Ae. aegypti exhibited greater sensitivity to temperature changes compared to Ae. albopictus, which displayed higher adaptability and resilience to environmental variations. Interaction effects were most evident at intermediate temperatures (25-30 °C), where RF exposure synergistically reduced developmental durations. However, extreme RF exposure levels and suboptimal temperatures prolonged developmental periods. This study highlights the critical role of temperature in mosquito development while identifying RF exposure as a potential modulator under specific conditions. The findings underscore the importance of considering both environmental and anthropogenic factors in vector management strategies. Future research should explore the molecular mechanisms underlying these interactions to refine predictive models and enhance vector control efforts in rapidly urbanizing regions.

Conclusion

In summary, temperature is the primary determinant of mosquito developmental durations, with RF exposure exerting secondary modulating effects under specific conditions. Ae. aegypti was more sensitive to environmental variations, while Ae. albopictus displayed greater resilience and adaptability. These findings provide a foundation for incorporating environmental variables, including anthropogenic factors such as RF exposure, into predictive models for mosquito population dynamics and vector management. Future research should explore the molecular mechanisms underlying these interactions and assess their implications for disease transmission and control in different ecological settings.


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Potential Effects of Anthropogenic Radiofrequency Radiation on Cetaceans

Balmori-de la Puente A, Balmori A. Potential Effects of Anthropogenic Radiofrequency Radiation on Cetaceans. Radiation. 2024; 4(1):1-16. doi: 10.3390/radiation4010001.

​Abstract

Cetaceans are cast to shore for a large number of reasons, although sometimes it is not clear why. This paper reviews the types and causes of cetacean strandings, focusing on mass strandings that lack a direct scientific explanation. Failure of cetacean orientation due to radiofrequency radiation and alterations in the Earth’s magnetic field produced during solar storms stand out among the proposed causes. This paper proposes the possibility that anthropogenic radiofrequency radiation from military and meteorological radars may also cause these strandings in areas where powerful radars exist. A search of accessible databases of military and meteorological radars in the world was carried out. Research articles on mass live strandings of cetaceans were reviewed to find temporal or spatial patterns in the stranding concentrations along the coast. The data showed certain patterns of spatial and temporal evidence in the stranding concentrations along the coast after radar setup and provided a detailed description of how radars may interfere with cetacean echolocation from a physiological standpoint. Plausible mechanisms, such as interference with echolocation systems or pulse communication systems, are proposed. This work is theoretical, but it leads to a hypothesis that could be empirically tested. Further in-depth studies should be carried out to confirm or reject the proposed hypothesis.

Simple Summary

The number of mass stranding events is dramatically increasing in recent decades affecting cetacean diversity and conservation. They consist in the accumulation of cetacean carcasses or live animals along the coast following certain temporal and spatial patterns. Although some cases can be explained based on a combination of physical or biological natural factors, direct human intervention is contributing to many of them. However, there are still many cases with unknown causes that demand to increase the efforts to describe possible new threats to cetacean species. In this context, we evaluate the potential effect of anthropogenic radiofrequency radiation (i.e., from meteorological and military radars) that has had a great expansion in the last years and is known to alter the magnetic receptor organs in several groups of animals. The aim of this work, was to conduct a bibliographic review reporting mass stranding events together with a search of radars in the vicinity areas. The results obtained suggest that anthropogenic radiofrequency radiation may be considered as a novel factor to understand some stranding events with unknown causes and proposes some plausible mechanisms of action.


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Biological effects of electromagnetic fields on insects: 
a systematic review and meta-analysis

Thill A, Cammaerts MC, Balmori A. Biological effects of electromagnetic fields on insects: a systematic review and meta-analysis. Rev Environ Health. 2023 Nov 23. doi: 10.1515/reveh-2023-0072.

Abstract

Worldwide, insects are declining at an alarming rate. Among other causes, the use of pesticides and modern agricultural practices play a major role in this. Cumulative effects of multiple low-dose toxins and the distribution of toxicants in nature have only started to be investigated in a methodical way. Existing research indicates another factor of anthropogenic origin that could have subtle harmful effects: the increasingly frequent use of electromagnetic fields (EMF) from man-made technologies. This systematic review summarizes the results of studies investigating the toxicity of electromagnetic fields in insects. The main objective of this review is to weigh the evidence regarding detrimental effects on insects from the increasing technological infrastructure, with a particular focus on power lines and the cellular network. The next generation of mobile communication technologies, 5G, is being deployed - without having been tested in respect of potential toxic effects. With humanity's quest for pervasiveness of technology, even modest effects of electromagnetic fields on organisms could eventually reach a saturation level that can no longer be ignored. An overview of reported effects and biological mechanisms of exposure to electromagnetic fields, which addresses new findings in cell biology, is included. Biological effects of non-thermal EMF on insects are clearly proven in the laboratory, but only partly in the field, thus the wider ecological implications are still unknown. There is a need for more field studies, but extrapolating from the laboratory, as is common practice in ecotoxicology, already warrants increasing the threat level of environmental EMF impact on insects.

Excerpt

Looking back at the history of science, it seems that adverse effects have frequently been reported early on, but mostly been ignored – e.g. in the cases of asbestos, lead and cigarettes. It has typically taken decades to understand the mechanisms of toxicity and for the official position to shift. The European Environment Agency EEA has produced several reports on this topic under the title “Late lessons from early warnings” [146, 147].

Thirty-six of the fifty-five HF-EMF studies reported in this review used field strengths lower than 6 V/m (∼100 mW/m2), and 31 of these 36 studies (86 %) nevertheless found statistically significant adverse effects, starting at about 2 V/m and peaking around 6 V/m. This is below the regulatory thresholds established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) (41 V/m, or 61 V/m above 2 GHz), and even below the particularly stringent installation limits only found in a handful of countries [94]. (The installation limit is measured where people can stay for long periods of time, i.e. homes, schools, working places and playgrounds for kids.)

Panagopoulos et al. detected a bioactive window at a distance of 20–30 cm from GSM mobile phones, where the power density equaled 100 mW/m2 (∼6 V/m), and where toxic effects in Drosophila are already observed after a 1-min exposure. These results have been replicated several times [148], [149], [150]. If this is generally true for insects, the limit for toxic effects would be 100 times below the current ICNIRP limit (10 W/m2 or 61 V/m), which protects only against thermal effects (in humans), and possibly 1,000 times lower than current limits for chronic exposure, i.e. 10 mW/m2 or 2 V/m (all comparisons based on power densities, i.e. energy per surface area units) [94]. A recent study found significant effects on gene transcription and chromosomal abnormalities using a WiFi signal at 4.8 mW/m2 or 1.35 V/m in Drosophila exposed for 9 days [145]. These findings of biological effects in insects starting at around 2 V/m imply that existing standards would have to be revised and made more stringent, to include nature protection/wild-life concerns.

Current ambient power densities are generally still below 10 or 100 mW/m2 (i.e. 2 or 6 V/m). A recent study measured values of 0.17–0.53 V/m in the field (0.1–0.8 mW/m2) [101]. Values mainly in the range of 0.5–1 V/m were found around schools in Crete [151]. Nationwide measurements of the National Observatory of electromagnetic fields (NOEF) in Greece found average values higher than 1 V/m in 55 % of sites, and values greater than 2 V/m in 20 % of measurement sites [152]. A recent review lists power densities ranging from 0.23 V/m in Swiss residential areas to 1.85 V/m in an Australian university neighborhood [86]. In urban hot spots (UK), a maximum of 150 mW/m2 (7.5 V/m) and an average of 25 mW/m2 (3.3 V/m) were measured (including WiFi) [153]. The French “Agence nationale des fréquences” (ANFR) found an average of 1.17 V/m at 1,300 5G base stations, and the authors expect a 20 % increase in the next years [154]. In Belgium, Italy, Switzerland, Russia and China, the installation limit is 6 V/m (100 mW/m2) for mobile telephony base stations, whereas Germany, the UK, the USA and many other countries adhere to the much higher ICNIRP limits [94, 155]. The ICNIRP limits have recently been questioned, since they are based on findings from more than 20 years ago, and their assumptions have been proven false [156]. Furthermore, the ICNIRP limits are designed to protect humans and have not been tested as to their adequacy in protecting wildlife and insects [157].

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Low-level EMF effects on wildlife and plants: 
What research tells us about an ecosystem approach

Levitt BB, Lai HC and Manville AM II. (2022) Low-level EMF effects on wildlife and plants: What research tells us about an ecosystem approach. Front. Public Health 10:1000840. doi: 10.3389/fpubh.2022.1000840.

Abstract

There is enough evidence to indicate we may be damaging non-human species at ecosystem and biosphere levels across all taxa from rising background levels of anthropogenic non-ionizing electromagnetic fields (EMF) from 0 Hz to 300 GHz. The focus of this Perspective paper is on the unique physiology of non-human species, their extraordinary sensitivity to both natural and anthropogenic EMF, and the likelihood that artificial EMF in the static, extremely low frequency (ELF) and radiofrequency (RF) ranges of the non-ionizing electromagnetic spectrum are capable at very low intensities of adversely affecting both fauna and flora in all species studied. Any existing exposure standards are for humans only; wildlife is unprotected, including within the safety margins of existing guidelines, which are inappropriate for trans-species sensitivities and different non-human physiology. Mechanistic, genotoxic, and potential ecosystem effects are discussed.

Excerpt

Radiofrequency radiation is a form of energetic air pollution and should be regulated as such (25). U.S. law (130) [42 USC § 7602 (g)] defines air pollution as:

“The term “air pollutant” means any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive (including source material, special nuclear material, and byproduct material) substance or matter which is emitted into or otherwise enters the ambient air. Such term includes any precursors to the formation of any air pollutant, to the extent the Administrator has identified such precursor or precursors for the particular purpose for which the term “air pollutant” is used.”

Unlike classic chemical toxicology pollutants in which a culprit can typically be identified and quantified, RFR may function as a “process” pollutant in the air not unlike how endocrine disruptors function in food and water in which the stressor causes a cascade of unpredictable systemic effects. The stimulus in the RFR analogy would be physical/energetic rather than chemical.

Long-term chronic low-level EMF exposure guidelines, which do not now exist, should be set accordingly for wildlife; mitigation techniques where possible should be developed; full environmental reviews should be conducted prior to the licensing/buildout of major new technologies like 5G; and environmental laws/regulations should be strictly enforced (25). We have a long over-due obligation to consider potential consequences to other species from our current unchecked technophoria—an obligation we have thus far not considered before species go extinct. In the views of these authors, the evidence requiring action is clear.

Open access paper: https://www.frontiersin.org/articles/10.3389/fpubh.2022.1000840

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Sep 26, 2021

The Effects of Non-Ionizing Electromagnetic Fields on Flora and Fauna 
(Levitt, Lai, and Manville) 

The journal, Reviews on Environmental Health, just published the final part of a three-part monograph that examines the effects of non-ionizing electromagnetic fields (EMF), including wireless radiation from cell towers and EMF from power lines, on flora and fauna. This 150-page tome (plus supplements) written by B. Blake Levitt, Henry Lai, and Albert Manville cites more than 1,200 references.

B. Blake Levitt, an award-winning journalist/author and former contributor to the New York Times, has specialized in medical and science writing for over three decades. Since the late 1970's, she has researched the biological effects of nonionizing radiation. Henry Lai is a scientist and bioengineering Professor Emeritus at the University of Washington and former Editor-in-Chief of Electromagnetic Biology and Medicine. Dr. Lai is best known for his research published in 1995 which concluded that low-level microwave radiation caused DNA damage in rat brains. Albert Manville is a retired branch manager and senior wildlife biologist in the Division of Migratory Bird Management at the U.S. Fish and Wildlife Service. Dr. Manville has served as an adjunct professor and lecturer for more than two decades at Johns Hopkins University where he has taught field classes in ecology, conservation biology, and wildlife management.

The abstracts and excerpts from this three-part monograph appear below. 

Effects of non-ionizing electromagnetic fields on flora and fauna, part 1. 
Rising ambient EMF levels in the environment
 
B. Blake Levitt, Henry C. Lai, Albert M. Manville. Effects of non-ionizing electromagnetic fields on flora and fauna, part 1. Rising ambient EMF levels in the environment.  Rev Environ Health. 2021 May 27. doi: 10.1515/reveh-2021-0026.

Abstract

Ambient levels of electromagnetic fields (EMF) have risen sharply in the last 80 years, creating a novel energetic exposure that previously did not exist. Most recent decades have seen exponential increases in nearly all environments, including rural/remote areas and lower atmospheric regions. Because of unique physiologies, some species of flora and fauna are sensitive to exogenous EMF in ways that may surpass human reactivity. There is limited, but comprehensive, baseline data in the U.S. from the 1980s against which to compare significant new surveys from different countries. This now provides broader and more precise data on potential transient and chronic exposures to wildlife and habitats. Biological effects have been seen broadly across all taxa and frequencies at vanishingly low intensities comparable to today’s ambient exposures. Broad wildlife effects have been seen on orientation and migration, food finding, reproduction, mating, nest and den building, territorial maintenance and defense, and longevity and survivorship. Cyto- and geno-toxic effects have been observed. The above issues are explored in three consecutive parts: Part 1 questions today’s ambient EMF capabilities to adversely affect wildlife, with more urgency regarding 5G technologies. Part 2 explores natural and man-made fields, animal magnetoreception mechanisms, and pertinent studies to all wildlife kingdoms. Part 3 examines current exposure standards, applicable laws, and future directions. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as ‘habitat’ so EMF can be regulated like other pollutants. Wildlife loss is often unseen and undocumented until tipping points are reached. Long-term chronic low-level EMF exposure standards, which do not now exist, should be set accordingly for wildlife, and environmental laws should be strictly enforced.

https://pubmed.ncbi.nlm.nih.gov/34047144/

Conclusion

Ambient background levels of EMF have risen sharply in the last four decades, creating a novel energetic exposure that previously did not exist at the Earth’s surface, lower atmospheric levels, or underwater environments. Recent decades have seen exponential increases in nearly all environments, including remote regions. There is comprehensive but outdated baseline data from the 1980s against which to compare significant new surveys from other countries which found increasing RFR levels in urban, suburban and remote areas, primarily from cell infrastructure/phone/WiFi exposures. One indicative comparison of similar sites between 1980 and today found a 70-fold (7,000%) increase in ambient RFR [149]. The increased infrastructure required for 5G networks will widely infuse the environment with new atypical exposures, as are increasing satellite systems communicating with ground-based civilian networks. The new information provides broader perspective with more precise data on both potential transient and chronic exposures to wildlife and habitats. Biological effects have been seen broadly across all taxa at vanishingly low intensities comparable to today’s ambient exposures as examined in Part 2. The major question presented in Part 1 was whether increasing anthropogenic environmental EMF can cause biological effects in wildlife that may become more urgent with 5G technologies, in addition to concerns over potentially more lenient allowances being considered by major standards-setting committees at FCC and ICNIRP (examined in Part 3). There are unique signaling characteristics inherent to 5G transmission as currently designed of particular concern to non-human species. Background levels continue to rise but no one is studying cumulative effects to nonhuman species.

379 references.

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Effects of non-ionizing electromagnetic fields on flora and fauna, Part 2 impacts: 
how species interact with natural and man-made EMF

B Blake Levitt, Henry C Lai, Albert M Manville. Effects of non-ionizing electromagnetic fields on flora and fauna, Part 2 impacts: how species interact with natural and man-made EMF. Rev Environ Health. 2021 Jul 8. doi:10.1515/reveh-2021-0050.

Abstract

Ambient levels of nonionizing electromagnetic fields (EMF) have risen sharply in the last five decades to become a ubiquitous, continuous, biologically active environmental pollutant, even in rural and remote areas. Many species of flora and fauna, because of unique physiologies and habitats, are sensitive to exogenous EMF in ways that surpass human reactivity. This can lead to complex endogenous reactions that are highly variable, largely unseen, and a possible contributing factor in species extinctions, sometimes localized. Non-human magnetoreception mechanisms are explored. Numerous studies across all frequencies and taxa indicate that current low-level anthropogenic EMF can have myriad adverse and synergistic effects, including on orientation and migration, food finding, reproduction, mating, nest and den building, territorial maintenance and defense, and on vitality, longevity and survivorship itself. Effects have been observed in mammals such as bats, cervids, cetaceans, and pinnipeds among others, and on birds, insects, amphibians, reptiles, microbes and many species of flora. Cyto- and geno-toxic effects have long been observed in laboratory research on animal models that can be extrapolated to wildlife. Unusual multi-system mechanisms can come into play with non-human species - including in aquatic environments - that rely on the Earth's natural geomagnetic fields for critical life-sustaining information. Part 2 of this 3-part series includes four online supplement tables of effects seen in animals from both ELF and RFR at vanishingly low intensities. Taken as a whole, this indicates enough information to raise concerns about ambient exposures to nonionizing radiation at ecosystem levels. Wildlife loss is often unseen and undocumented until tipping points are reached. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as 'habitat' so EMF can be regulated like other pollutants. Long-term chronic low-level EMF exposure standards, which do not now exist, should be set accordingly for wildlife, and environmental laws should be strictly enforced - a subject explored in Part 3.


Conclusion

Effects from both natural and man-made EMF over a wide range of frequencies, intensities, wave forms, and signaling characteristics have been observed in all species of animals and plants investigated. The database is now voluminous with in vitro, in vivo, and field studies from which to extrapolate. The majority of studies have found biological effects at both high and low-intensity man-made exposures, many with implications for wildlife health and viability. It is clear that ambient environmental levels are biologically active in all non-human species which can have unique physiological mechanisms that require natural geomagnetic information for their life’s most important activities. Sensitive magnetoreception allows living organisms, including plants, to detect small variations in environmental EMF and react immediately as well as over the long term, but it can also make some organisms exquisitely vulnerable to man-made fields. Anthropogenic EMF may be contributing more than we currently realize to species’ diminishment and extinction. Exposures continue to escalate without understanding EMF as a potential causative and/or co-factorial agent. It is time to recognize ambient EMF as a potential novel stressor to other species, design technology to reduce exposures to as low as reasonably achievable, keep systems wired as much as possible to reduce ambient RFR, and create laws accordingly — a subject explored more thoroughly in Part 3.


675 references.

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Effects of non-ionizing electromagnetic fields on flora and fauna, Part 3. 
Exposure standards, public policy, laws, and future directions

B. Blake Levitt, Henry C. Lai, Albert M. Manville. Effects of non-ionizing electromagnetic fields on flora and fauna, Part 3. Exposure standards, public policy, laws, and future directions. Rev Environ Health. 2021 Sep 27. doi: 10.1515/reveh-2021-0083.

Abstract

Due to the continuous rising ambient levels of nonionizing electromagnetic fields (EMFs) used in modern societies—primarily from wireless technologies—that have now become a ubiquitous biologically active environmental pollutant, a new vision on how to regulate such exposures for non-human species at the ecosystem level is needed. Government standards adopted for human exposures are examined for applicability to wildlife. Existing environmental laws, such as the National Environmental Policy Act and the Migratory Bird Treaty Act in the U.S. and others used in Canada and throughout Europe, should be strengthened and enforced. New laws should be written to accommodate the ever-increasing EMF exposures. Radiofrequency radiation exposure standards that have been adopted by worldwide agencies and governments warrant more stringent controls given the new and unusual signaling characteristics used in 5G technology. No such standards take wildlife into consideration. Many species of flora and fauna, because of distinctive physiologies, have been found sensitive to exogenous EMF in ways that surpass human reactivity. Such exposures may now be capable of affecting endogenous bioelectric states in some species. Numerous studies across all frequencies and taxa indicate that low-level EMF exposures have numerous adverse effects, including on orientation, migration, food finding, reproduction, mating, nest and den building, territorial maintenance, defense, vitality, longevity, and survivorship. Cyto- and geno-toxic effects have long been observed. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as ‘habitat’ so EMF can be regulated like other pollutants. Wildlife loss is often unseen and undocumented until tipping points are reached. A robust dialog regarding technology’s high-impact role in the nascent field of electroecology needs to commence. Long-term chronic low-level EMF exposure standards should be set accordingly for wildlife, including, but not limited to, the redesign of wireless devices, as well as infrastructure, in order to reduce the rising ambient levels (explored in Part 1). Possible environmental approaches are discussed. This is Part 3 of a three-part series.

Excerpts

Introduction

This is Part 3 and concludes a three-part series on electromagnetic field (EMF) effects to wildlife.

Part 1 focused on measurements of rising background levels in urban, suburban, rural, and deep forested areas as well as from satellites. Discussed were different physics models used to determine safety and their appropriateness to current exposures. The unusual signaling characteristics and unique potential biological effects from 5G were explored. The online edition of Part 1 contains a Supplement Table of measured global ambient levels.

Part 2 is an in-depth review of species extinctions, exceptional non-human magnetoreception capabilities, and other species’ known reactions to anthropogenic EMF exposures as studied in laboratories and in the field. All animal kingdoms are included and clear vulnerabilities are seen. Part 2 contains four Supplement Tables of extensive low-level studies across all taxa, including ELF/RFR genotoxic effects.

Part 3 discusses current exposure standards, existing federal, and international laws that should be enforced but often are not, and concludes with a detailed discussion of aeroecology—the concept of defining air as habitat that would serve to protect many, though not all, vulnerable species today.

Some solutions

Existing environmental laws in the U.S., Canada, and throughout Europe should be enforced. For example, in the U.S., NEPA and its EISs should be required each time a new broadly polluting EMF technology like 5G is introduced, not as the current policy is being interpreted through “CatEx” or simple dismissal. EISs should be required for all new technologies that create pervasive ambient EMF such as ‘smart’ grid/metering, Distributed Antenna Systems (DAS), small cell networks, and the 5G “Internet of Things.” Where wildlife species are affected, systems and networks that currently meet radiation levels for CatEx (and are therefore exempt from review) should be required to develop/implement NEPA and EIS reviews for cumulative exposures to wildlife from multi-transmission sources.

Efforts should begin to develop acceptable exposure and emissions standards for wildlife, which today do not exist. Setting actual exposure standards for wildlife will be an enormous challenge, and for some species there may be no safe thresholds, especially with 5G and MMW. We may simply need to back away from many wireless technologies altogether, especially the densification of infrastructure, and refocus on developing better dedicated wired systems in urban, suburban and rural areas. Environmentally sensitive wilderness areas should be considered off limits for wireless infrastructure. Once air is seen as ‘habitat,’ there may come a time when a cell phone call voluntarily not made will be understood as removing something detrimental from air’s waste-stream, the way we now see plastic bags regarding terrestrial/aquatic pollution.

There are some reasonably simple things that can be done in the ELF ranges that would benefit insect, bird, and many wild mammal and ruminant species. For example, high-tension electric utility corridors can be built or changed to cancel magnetic fields with different wiring configurations. This is already widely done in the industry for other reasons but it also coincidentally eliminates at the source at least the magnetic field component for wildlife. There are other approaches too but further discussion is beyond the scope of this paper.

Research into the long-term, low-level ambient exposures to humans and wildlife is imperative given the picture that is emerging. There is a likelihood that low-level ambient EMF is a factor, or co-factor, in some of the adverse environmental effects we witness today—many previously discussed in this series of papers. There is currently no research in any industrialized country that looks to the broader implications to all flora and fauna from these rising background levels, even as effects to individual species are observed. This is an important, emerging environmental issue that must be addressed.

Conclusions

In this broad three-part review, we sought to clarify if rising ambient levels of EMF were within the range of effects observed in in vitro, in vivo, and field studies in all animal phyla thus far investigated. We further discussed mechanisms pertinent to different animal physiology, behavior, and unique environments. The intention was to determine if current levels have the ability to impact wildlife species according to current studies. The amount of papers that find effects at today’s EMF levels to myriad species is robust. Some unusual patterns did emerge, including broadly in flora that react beneficially to static EMF but adversely to AC-ELF and especially to RFR.

There is a very large database supporting the hypothesis that effects occur in unpredictable ways in numerous species in all representative taxa from modern ambient exposures. Associations are strong enough to warrant caution. New enlightened public policies are needed, as well as existing laws enforced, reflecting a broader understanding of non-human species’ interactions with environmental EMF. Emerging areas, such as aeroecology, help define airspace as habitat and bring better awareness of challenges faced by aerial species—including animals and plants. But we are in the nascent stages of understanding the full complexity and detailed components of electroecology—the larger category of how technology affects all biology and ecosystems.

Historically, control over the realm of nonionizing radiation has been the purview of the physics and engineering communities. It is time that the more appropriate branches of biological science, specializing in living systems, stepped up to fill in larger perspectives and more accurate knowledge. We need to task our technology sector engineers to create safer products and networks with an emphasis on wired systems, and to keep all EMF exposures as low as reasonably achievable.

Corresponding author: B. Blake Levitt, P.O. Box 2014, New Preston, CT 06777, USA, E-mail: 
aeroecology; electroecology; International Council on Non-ionizing Radiation Protection (ICNIRP); Migratory Bird Treaty Act (MBTA); National Environmental Policy Act (NEPA); non-ionizing electromagnetic fields (EMFs); radiofrequency radiation (RFR); rising ambient levels; U.S. Federal Communications Commission (FCC)

162 references.


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Electromagnetic radiation as an emerging driver factor for the decline of insects

Alfonso Balmori. Electromagnetic radiation as an emerging driver factor for the decline of insects. Sci Total Environ. Available online 28 January 2021, 144913. https://doi.org/10.1016/j.scitotenv.2020.

Highlights

• Biodiversity of insects is threatened worldwide
• This reductions is mainly attributed to agricultural practice and pesticide use
• There is sufficient evidence on the damage caused by electromagnetic radiation
• Electromagnetic radiation may be a complementary driver in this decline
• The precautionary principle should be applied before any new deployment (e.g. 5G)

Abstract

The biodiversity of insects is threatened worldwide. Numerous studies have reported the serious decline in insects that has occurred in recent decades. The same is happening with the important group of pollinators, with an essential utility for pollination of crops. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and ecosystem services. Many authors point out that reductions in insect abundance must be attributed mainly to agricultural practices and pesticide use. On the other hand, evidence for the effects of non-thermal microwave radiation on insects has been known for at least 50 years. The review carried out in this study shows that electromagnetic radiation should be considered seriously as a complementary driver for the dramatic decline in insects, acting in synergy with agricultural intensification, pesticides, invasive species and climate change. The extent that anthropogenic electromagnetic radiation represents a significant threat to insect pollinators is unresolved and plausible. For these reasons, and taking into account the benefits they provide to nature and humankind, the precautionary principle should be applied before any new deployment (such 5G) is considered.


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Effects of Non-Ionizing Electromagnetic Pollution on Invertebrates, Including Pollinators Such as Honey Bees: What We Know, What We Don’t Know, and What We Need to Know

Friesen M, Havas M. 2020. Effects of Non-Ionizing Electromagnetic Pollution on Invertebrates, Including Pollinators Such as Honey Bees: What We Know, What We Don’t Know, and What We Need to Know.” Pages 127-138 In Working Landscapes. Proceedings of the 12th Prairie Conservation and Endangered Species Conference, February 2019, Winnipeg, Manitoba. Edited by D. Danyluk. Critical Wildlife Habitat Program, Winnipeg, Manitoba. http://pcesc.ca/media/45404/final-2019-pcesc-proceedings.pdf.

Abstract

Invertebrates, including pollinators such as honey bees, can be adversely affected by non-ionizing electromagnetic radiation (EMR). Sources contributing to common environmental EMR exposures include antennae (cell phone, broadcast, and radar), communications satellites, and power lines. Adverse biochemical changes and disorientation have been reported for honey bees and other invertebrates. Field studies have reported changes in abundance and composition of “key pollinator groups” (wild bees, hoverflies, bee flies, beetles, and wasps) that have been attributed to emissions from telecommunications towers. We take a close look at the biological effects on invertebrates of EMR reported in the scientific literature and a general look at evidence from studies on plants, birds, humans, and other animals (domestic, laboratory, wild). We discuss possible implications of excessive electromagnetic pollution on ecosystems and identify knowledge gaps and what we need to know before more electromagnetic pollution is added to the environment, especially in the form of 5G.

Introduction

Invertebrates (animals without backbones) are major components of most ecosystems. Insects are key to the integrity of many ecosystems in many roles including as pollinators. Honey bees play a role in pollination of domestic as well as wild plants and are often used as bio-indicator species and as a “model” to examine environmental problems. The global decline of pollinators is of grave concern and efforts are being made to identify the reasons (Potts et al. 2010; Sánchez-Bayo and Wyckhuys 2019). One factor not widely considered is the possible role of anthropogenic electromagnetic radiation (EMR).

Electromagnetic fields (EMFs) are invisible electric and magnetic fields of force. All living organisms have evolved in Earth’s natural EMFs and depend on them to live. Natural sources include Earth’s static magnetic field, and static electricity, including differences in charges among clouds and the earth that can lead to lightning. Electromagnetic radiation (EMR) originates when fields change.

Anthropogenic (human-made, artificial) EMR sources are sometimes referred to as electromagnetic pollution or electrosmog. The main frequency ranges of interest in this article are: 1) extremely low frequencies (ELF) of 50/60 to 90 Hz that emanate from sources such as power lines and building wiring; and 2) radiofrequency radiation (RFR) of 700 MHz to 6 GHz, commonly used for devices such as cell phones, radio and television, and their supporting infrastructure, e.g., cell towers, antennae on buildings, and orbiting communications satellites. Also discussed are frequencies currently being developed and deployed above 6 GHz for 5G (5th Generation) for faster and more pervasive connectivity, including the “Internet of Things”.


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Risk to pollinators from anthropogenic electro-magnetic radiation: Evidence and knowledge gaps

Vanbergen AJ, Potts SG, Vian A, Malkemper EP, Young J, Tscheulin T. Risk to pollinators from anthropogenic electro-magnetic radiation (EMR): Evidence and knowledge gaps. Sci Total Environ. 2019 Aug 7;695:133833. doi: 10.1016/j.scitotenv.2019.133833.

Highlights

• Anthropogenic electromagnetic radiation (light, radiofrequency) is perceived to threaten pollinators and biodiversity.
• Potential risks are artificial light at night (ALAN) and anthropogenic radiofrequency electromagnetic radiation (AREMR).
• We assessed the quantity and quality of evidence, and the level of consensus, to distil key messages for science and policy.
• ALAN can alter pollinator communities and functions, although this remains to be well established.
• Evidence of AREMR impacts is inconclusive due to a lack of high quality, field-realistic studies.
• Whether pollinators and pollination face a threat from the spread of ALAN or AREMR remains a major knowledge gap.

Abstract

Worldwide urbanisation and use of mobile and wireless technologies (5G, Internet of Things) is leading to the proliferation of anthropogenic electromagnetic radiation (EMR) and campaigning voices continue to call for the risk to human health and wildlife to be recognised. Pollinators provide many benefits to nature and humankind, but face multiple anthropogenic threats. Here, we assess whether artificial light at night (ALAN) and anthropogenic radiofrequency electromagnetic radiation (AREMR), such as used in wireless technologies (4G, 5G) or emitted from power lines, represent an additional and growing threat to pollinators. A lack of high quality scientific studies means that knowledge of the risk to pollinators from anthropogenic EMR is either inconclusive, unresolved, or only partly established. A handful of studies provide evidence that ALAN can alter pollinator communities, pollination and fruit set. Laboratory experiments provide some, albeit variable, evidence that the honey bee Apis mellifera and other invertebrates can detect EMR, potentially using it for orientation or navigation, but they do not provide evidence that AREMR affects insect behaviour in ecosystems. Scientifically robust evidence of AREMR impacts on abundance or diversity of pollinators (or other invertebrates) are limited to a single study reporting positive and negative effects depending on the pollinator group and geographical location. Therefore, whether anthropogenic EMR (ALAN or AREMR) poses a significant threat to insect pollinators and the benefits they provide to ecosystems and humanity remains to be established.



Oct 31, 2018

EKLIPSE Project: Electromagnetic fields threaten wildlife

Implications for 5G deployment

A new report found that electromagnetic fields emitted by power lines, Wi-Fi, broadcast and cell towers pose a “credible” threat to wildlife, and that 5G (fifth generation cellular technology) could cause greater harm.

The analysis of 97 peer-reviewed studies by the EKLIPSE project concluded that electromagnetic radiation (EMR) is a potential risk to insect and bird orientation and to plant health.

The report concluded that: 
  • EMR represents a potential risk to the orientation or movement of invertebrates and may affect insect behavior and reproduction;
  • bird orientation can be disrupted by weak magnetic fields in the radiofrequency range, and the same may be true for other vertebrates including mammals; and
  • EMR exposure may affect plant metabolism due to production of reactive oxygen species often resulting in reduced plant growth.
  • Moreover, there is “an urgent need to strengthen the scientific basis of the knowledge on EMR and their potential impacts on wildlife.”
The review was conducted by a multidisciplinary, expert steering group composed of four biologists/ecologists who specialized in different taxonomic groups, and two physicists who study electromagnetic fields. This technical report represents the first step in an analysis of currently available knowledge and future research needs.

The reviewers pointed out the need for more high quality research. They rated the quality of 82 studies--56 had good to excellent biologic or ecologic quality, and 39 had good to excellent technical quality.

EKLIPSE (Establishing a European Knowledge and Learning Mechanism to Improve the Policy-Science-Society Interface on Biodiversity and Ecosystem Services) is funded by the European Union to answer requests from policy makers and other societal actors on biodiversity-related issues.

For more information about the EKLIPSE conference held January 22-25, 2018, including slides and video, see: http://www.eklipse-mechanism.eu/emr_conference.

References

Malkemper EP, Tscheulin T, VanBergen AJ, Vian A, Balian E, Goudeseune L (2018). The impacts of artificial Electromagnetic Radiation on wildlife (flora and fauna). Current knowledge overview: a background document to the web conference. A report of the EKLIPSE project. http://bit.ly/Eklipseoverview

Goudeseune L, Balian E, Ventocilla J (2018). The impacts of artificial Electromagnetic Radiation on wildlife (flora and fauna). Report of the web conference. A report of the EKLIPSE project. http://bit.ly/EKLIPSEconfreport

Also see:

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The EKLIPSE review was conducted at the request of Buglife, the only European organization devoted to the conservation of invertebrates. Invertebrates are vitally important to humans and other life forms which could not survive without them; yet, thousands of species are declining, and many are heading towards extinction. 

According to a news story in The Telegraph:

“… the charity Buglife warned that despite good evidence of the harms there was little research ongoing to assess the impact, or apply pollution limits.

The charity said ‘serious impacts on the environment could not be ruled out’ and called for 5G transmitters to be placed away from street lights, which attract insects, or areas where they could harm wildlife.

Matt Shardlow, CEO of Buglife said: ‘We apply limits to all types of pollution to protect the habitability of our environment, but as yet, even in Europe, the safe limits of electromagnetic radiation have not been determined, let alone applied.

There is a credible risk that 5G could impact significantly on wildlife, and that placing transmitters on LED street lamps, which attract nocturnal insects such as moths increases exposure and thereby risk.

Therefore we call for all 5G pilots to include detailed studies of their influence and impacts on wildlife, and for the results of those studies to be made public.’

Buglife called for 5G transmitters to be moved away from street lights where insects are drawn.

As of March, 237 scientists have signed an appeal to the United Nations asking them to take the risks posed by electromagnetic radiation more seriously.”


Additional Resources (Updated August 14, 2021)

Aikaterina L, Stefi AL, Vassilacopoulou D, Margaritis LH, Christodoulakis NS. Oxidative stress and an animal neurotransmitter synthesizing enzyme in the leaves of wild growing myrtle after exposure to GSM radiation. Flora. 243:67-76. June 2018. https://doi.org/10.1016/j.flora.2018.04.006


Granger J, Walkowicz L, Fitak R, Johnsen S. Gray whales strand more often on days with increased levels of atmospheric radio-frequency noise. Curr Biol. 2020 Feb 24;30(4):R155-R156. https://www.ncbi.nlm.nih.gov/pubmed/32097638

Lupi D, Mesiano MP, Adani A, Benocci R, Giacchini R, Parenti P, Zambon G, Lavazza A, Boniotti MB, Bassi S, Colombo M, Tremolada P. 2021. Combined Effects of Pesticides and Electromagnetic-Fields on Honeybees: Multi-Stress Exposure. Insects. 12(8):716. doi: 10.3390/insects12080716. https://www.mdpi.com/2075-4450/12/8/716

Nyqvist D, Durif C, Johnsen MG, De Jong K, Forland TN, Sivle LD. Electric and magnetic senses in marine animals, and potential behavioral effects of electromagnetic surveys. Mar Environ Res. 2020 Mar;155:104888. https://www.ncbi.nlm.nih.gov/pubmed/32072990

Panagopoulos DJ, Balmori A, Chrousos GP. On the biophysical mechanism of sensing upcoming earthquakes by animals. Sci Total Environ. 2020 Jan 29;717:136989. https://www.ncbi.nlm.nih.gov/pubmed/32070887

Russell, C. Wireless Silent Spring. Santa Clara County Medical Association Bulletin. Oct 2018. http://www.sccma-mcms.org/Portals/19/SilentSpringAticle_color_pr2.pdf

Wednesday, August 13, 2025

NIEHS Cell Phone Radiation Studies


US Government Releases Report on Pilot Studies of Cell Phone Radiation and DNA Damage


Safety is not assured and questions remain unanswered. 


Electromagnetic Radiation Safety, August 13, 2025


In August 2025, the National Institute of Environmental Health Sciences (NIEHS) published a peer-reviewed report online that described its pilot studies on cell phone radiation exposure conducted by the Division of Translational Toxicology (DTT). These pilot studies were launched specifically “to better understand the biological mechanisms that produced tumor development and DNA damage” as reported in the 2018 rodent studies conducted by the NIEHS National Toxicology Program (NTP).

Although the pilot studies reported “limited findings” and claimed no DNA damage in its 5-day exposure tests, these results cannot be used to conclude that cell phone radiation is safe. Not only were the experiments short-term and limited in scope, but contrary to the stated conclusion of no effects, the authors reported statistically significant evidence of DNA damage. These findings do not negate the findings from the earlier NTP research that reported animals exposed to 14 to 19 weeks of cell phone radiation experienced DNA damage.

The NIEHS's decision to disregard the findings of the DTT and NTP studies, which linked cell phone radiation to DNA damage and cancer, and to halt further research on this environmental carcinogen, represents a failure to uphold its mandate of protecting public health.

The DTT Pilot Studies

The DTT developed a small-scale radio frequency radiation (RFR) exposure system with a signal generator capable of generating a broader array of RF signals than the 2G/3G signals employed in the NTP studies. This system was developed to allow for efficient testing of later generations of cell phone technology (e.g., 4G and 5G).

To help understand the NTP studies, the DTT conducted 2G/3G pilot studies that were limited to 5 days of exposure and used smaller sample sizes compared to the original NTP studies. Nevertheless, these peer-reviewed studies found statistically-significant (p < .05) (in addition to marginally-significant, p < .10) trend effects of cell phone radiation on DNA damage (Wyde et al., 2025):

Male rats: GSM -- hippocampus (p-trend = .002), blood (p-trend = .053), frontal cortex (p-trend = .064)
Female rats: CDMA -- frontal cortex  (p-trend = .043)
Male mice: CDMA --  liver (p-trend = .010), heart (p-trend = .054), blood (p-trend = .077)

Numerous peer-reviewed studies have reported DNA damage caused by cell phone radiation exposure (e.g., Weller et al., 2025Lai, 2021) in addition to the earlier NTP studies. Thus, it is surprising that the DTT report dismissed these adverse effects calling them of "uncertain biological significance."

Overcoming technical challenges, the DTT developed a prototype capable of testing the effects of later generations of cell phone technology. The DTT report concluded:

"Despite a number of difficulties (i.e., engineering requirements, system modifications, measurement of body temperature during exposure), this small-scale RFR exposure system presents a prototype for investigative toxicological studies by researchers interested in conducting experimental RFR studies in rodent models. High-quality studies to understand the effects of RFR exposure on biological responses are needed given the widespread human exposure to RFR associated with cell phone use." 

However, on August 7, 2025, contrary to the results of the DTT report, the NIEHS posted on its website:

 "Also, NIEHS researchers found that exposure to RFR did not induce DNA damage, after five days of continuous exposure, up to 9 watts/kg in rats and 15 watts/kg in mice." https://ntp.niehs.nih.gov/research/topics/cellphones 

And contrary to the report's conclusions, the NIEHS stated:

"The research using this small-scale RFR exposure system was technically challenging and more resource intensive than expected... no further work with this RFR exposure system will be conducted and NIEHS has no further plans to conduct additional RFR exposure studies at this time." https://ntp.niehs.nih.gov/research/topics/cellphones

Results of the NTP Studies

https://www.niehs.nih.gov/sites/default/files/NTP_cell_phone_factsheet_jan_2024_508.pdf

Based on the NTP studies, the NIEHS published a peer-reviewed paper which concluded that exposure to radio frequency radiation (RFR) is associated with an increase in DNA damage (Smith-Roe et al., 2020). The NTP found significant increases in DNA damage in the frontal cortex of male mice (both modulations--GSM and CDMA), leukocytes of female mice (CDMA only), and hippocampus of male rats (CDMA only) from 14-19 weeks of exposure to cell phone radiation. Increases in DNA damage judged to be equivocal were observed in several other tissues of rats and mice. 


Comparison of 2018 NTP Studies and 2025 DTT Pilot Studies 


2018 NTP Studies

2025 DTT Pilot Studies

Purpose

Comprehensive evaluation of cancer and DNA damage risks from long-term cell phone radiofrequency radiation exposure in male and female rats and mice

Mechanistic follow-up to explore possible biological pathways for tumor and DNA damage seen in the 2018 NTP study in male and female rats and male mice

Exposure Duration

14 to 19 weeks for DNA genotoxicity tests


2 years for carcinogenicity study

5 days for DNA genotoxicity tests

Pre-natal Exposure

Yes, for male and female rats, studies began on gestation day 6.

No, for male mice, 5-6 weeks old on first day of study.

No, male rats were 28–31 weeks old, female rats were 23 weeks old, and male mice were 33 weeks old on first day of study.

Cancer 

Increased tumors in male rats:

  • Clear evidence of cancer in the heart (malignant schwannoma)

  • Some evidence of cancer in the brain (malignant glioma)

  • Some evidence of tumors in the adrenal glands (benign, malignant, or complex combined pheochromocytoma)


Did not test for cancer

DNA Damage

Significant increases in DNA damage in:


  • the hippocampus of male rats,

  • the frontal cortex of the brain in male mice, and

  • the blood cells of female mice.


Although report concluded RFR exposure for 5 days did not induce DNA damage, the studies found significant increases in DNA damage in:


  • the hippocampus of male rats,

  • the frontal cortex of the brain in female rats, and

  • the liver in male mice.

 


Related posts:

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Cell Phone Radiation Follow-up Studies

NIEHS, August 7, 2025

"NIEHS scientists in the Division of Translational Toxicology, which supports the NTP, undertook research to better understand some of the findings seen in the earlier RFR rodent studies reported in NTP Technical reports TR-595 and TR-596.

They designed and developed a novel custom small-scale RFR exposure system, which included building, testing, and validating the exposure system. This new exposure system was based on the system used in the published NTP rodent studies. Researchers then conducted a series of short-term in vivo rodent studies.

NIEHS has completed the follow-up studies with this small-scale RFR exposure system. The results from these follow-up studies are published in a peer-reviewed report posted on the NIEHS website (see sidebar).

The research using this small-scale RFR exposure system was technically challenging and more resource intensive than expected. In addition, this exposure system was designed to study the frequencies and modulations used in 2G and 3G devices, but is not representative of newer technologies such as 4G/4G-LTE, or 5G (which is still not fully defined). Taking these factors into consideration, no further work with this RFR exposure system will be conducted and NIEHS has no further plans to conduct additional RFR exposure studies at this time."

RFR Follow-up Studies

"Following publication of the NTP RFR studies, NIEHS scientists conducted additional research to better understand the biological mechanisms that produced tumor development and DNA damage in exposed rodents. Specifically, they set out to understand if the health effects seen in the original studies were due to direct RFR exposure or RFR-induced changes in the temperature of body-tissue.

The scientists designed and developed a RFR exposure system that employed sub-cutaneous chips and implanted temperature data loggers to measure internal body temperature of rodents. Technical advances of the system also supported improved control of the exposure process and testing of 2G, 3G, 4G-LTE, and unmodulated RF signals. The scientists conducted short-term studies using the new system.

The scientists obtained some limited results. For example, scientists observed no changes in rodent behavior during operation of the RFR exposure system. Also, NIEHS researchers found that exposure to RFR did not induce DNA damage, after five days of continuous exposure, up to 9 watts/kg in rats and 15 watts/kg in mice.

Despite these findings, the new RFR exposure system left the body temperature question unanswered. Neither the microchips nor the data loggers successfully measured internal body temperature of the test rodents making it impossible to draw conclusions about the role of tissue heating in RFR-induced toxicity and carcinogenicity. The system is also incapable of testing many of the frequencies associated with newer 5G cell phone technology. It became clear that this experimental approach is insufficient for additional RFR research by NIEHS.

Nevertheless, the study generated useful exposure information that may support further study by other organizations.

The full, peer-reviewed report of the study is published under the title of Development and Testing of a Novel Whole-Body Exposure System for Investigative Studies of Radiofrequency Radiation in Rodents on the NIEHS website."

https://ntp.niehs.nih.gov/research/topics/cellphones

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Development and testing of a novel whole-body exposure system for investigative studies of radiofrequency radiation in rodents

Wyde ME, Capstick M, Hall SM, Hooth MJ, Kuster N, Ladbury JM, Roberts GK, Shipkowski KA, Shockley KS, Smith-Roe SL, Stout MD, Walker NJ. 2025. Development and testing of a novel whole-body exposure system for investigative studies of radiofrequency radiation in rodents. Research Triangle Park, NC: National Institute of Environmental Health Sciences. [https://doi.org/10.22427/NIEHS-RFR]

Executive Summary

"The predominant source of human exposure to radiofrequency radiation (RFR) occurs through the use of cell phone handsets. Previous toxicology studies on RFR, conducted in support of the National Toxicology Program (NTP) by researchers at the National Institute of Environmental Health Sciences (NIEHS), found exposure-related effects on body temperature and DNA damage. The studies reported herein were conducted by NIEHS researchers in the Division of Translational Toxicology to better understand the biological mechanisms that produced tumor development and DNA damage in exposed rodents. These studies were not conducted as part of the NTP.

The goals of the current research were to design, construct, and use a small-scale RFR exposure system to conduct toxicological research in rats and mice. One of the primary specific objectives of this research was to test and use new, experimental methods to collect physiological data from animals in real time during RFR exposures, including assessment of body temperature and use of videos for clinical observations. Previously, such data collections were not feasible without cessation of RFR exposure.

A new RFR exposure system based on the technical parameters of the system used in the previous NTP toxicology and carcinogenesis studies was developed for small-scale investigative studies with fewer animals. The system was designed with enhanced capabilities and more flexibility, including the ability to generate additional radiofrequency (RF) signals with frequencies and modulations used in more current wireless communication technologies. After development and installation, the system was rigorously tested and independently verified before animal studies were conducted. Following completion of the mouse study, several system modifications were required before the rat studies could be conducted. These system modifications required significant technical expertise and sometimes took several months to resolve successfully.

A series of 5-day studies was conducted in male or female Sprague Dawley (Hsd:Sprague Dawley® SD®) rats or B6C3F1/N mice to evaluate the effect of exposure to the same Code Division Multiple Access (CDMA)- or Global System for Mobile Communications (GSM)-modulated RF signals used in the previous NTP studies. Video from the cameras in the exposure chambers demonstrated no visible response in either rats or mice at the first time the exposure system was activated, at subsequent system on/off transitions, or during the periods of exposure. Exposure to RFR for 5 days did not induce DNA damage in brain cells (frontal cortex, hippocampus, and cerebellum), or in liver, heart, or blood cells of rats and mice, as measured using the comet assay. These investigative studies of RFR exposure were technically challenging to conduct and, unfortunately, measurement by two different methods did not yield data useful for assessing body temperature during exposure.

Despite a number of difficulties (i.e., engineering requirements, system modifications, measurement of body temperature during exposure), this small-scale RFR exposure system presents a prototype for investigative toxicological studies by researchers interested in conducting experimental RFR studies in rodent models. High-quality studies to understand the effects of RFR exposure on biological responses are needed given the widespread human exposure to RFR associated with cell phone use. The aim of this report is to share knowledge and facilitate advancement in research methodologies for investigating the potential health effects of RFR."

Excerpts

"In the current studies, male rats were exposed to CDMA or GSM-modulated RFR, and female rats and male mice were exposed to CDMA-modulated RFR."

"Based on the homogeneity results of previous analyses that modeled the specific absorption rate (SAR) distribution of RFR across the whole body, rats were exposed at a frequency of 900 MHz, and mice were exposed at 1,900 MHz."

"While reviewing videos captured during exposure (see Section 4.2.3.5), it was noted that the stirrer on the back wall of the control chamber (Chamber 4) did not move throughout the four experiments (male mouse CDMA, male rat CDMA, female rat CDMA, male rat GSM)."

"The signal generator (SMBV-100A, Rhode & Schwarz, Germany) chosen was capable of generating the types of signals used in the previous NTP RFR studies."

"These chambers and the studies described in Section 4.2 utilized a 10-minute on/10-minute off alternating exposure paradigm by which animals in each chamber were exposed for 9 hours and 10 minutes per day over an 18-hour and 20-minute exposure period."

"An RFR field exposure system was designed to enable equivalent exposure conditions to those utilized in the previous NTP 2-year studies and for a smaller number of animals with a smaller facility footprint."

Figure 3: The mouse CDMA study was conducted in July 2020. The rat studies were conducted from September to November 2021.

"During the acclimation period, prior to the start of exposure, it was discovered that the rats were able to chew through the cage filter tops and escape their cage units."

"After system installation, verification, and qualification were completed, a series of four 5-day studies was conducted in Sprague Dawley (Hsd:Sprague Dawley ® SD®) rats or B6C3F1/N mice. The goal of these studies was to further characterize radiofrequency radiation (RFR)-induced changes in body temperature and DNA damage observed in the previous National Toxicology Program (NTP) RFR studies and evaluate the use of new methods for collecting live, real-time data."

"On the first day of the studies, rats were approximately 28–31 weeks (male) or 23 weeks (female) old, and male mice were approximately 33 weeks old. Rats and mice were randomly assigned to one of five exposure groups before the start of the study. Randomization was stratified by body weight that produced similar group mean weights using NTP Provantis software (Instem, Stone, UK)."

"Groups of 10 male and 10 female rats and 10 male mice were housed individually in reverberation chambers and exposed to whole-body RFR via Code Division Multiple Access (CDMA) (Interim Standard 95 [IS-95], 1,900 MHz) or via Global System for Mobile Communications (GSM) single modulation (900 MHz)."

"These studies were conducted under the NIEHS contract with Battelle Memorial Institute (HHSN273201400015C). The studies were initiated at the Battelle testing facility in West Jefferson, Ohio. On May 1, 2021, the testing facility was transferred to a new company, AmplifyBio....For the mouse study, all of the in-life, postmortem, and analytical portions of the study were conducted while Battelle was the testing facility; reporting was conducted under AmplifyBio as the testing facility. The rat studies were conducted under AmplifyBio as the testing facility."

"Body temperature data were unusable because of data quality or data collection issues."

"There were no exposure-related effects on survival or body weights with CDMA-modulated RFR exposure up to 9 W/kg for 5 days in male rats."

"There were no exposure-related effects on body weights with GSM-modulated RFR exposure up to 9 W/kg for 5 days in male rats. On study day 5, body weights showed a negative trend and a significant decrease in the 6 W/kg group compared to the chamber control group."

"Statistical methods were chosen based on distributional assumptions. Unless specifically mentioned, all endpoints were tested for a trend across exposure groups, followed by pairwise tests for each exposed group against the chamber control group. Significance of all trend and pairwise tests is determined by a p value of ≤0.05 and is reported at both 0.05 and 0.01 levels. The room control group was analyzed only by a single pairwise comparison to the chamber control group. The room control analysis was kept separate from that of the other exposed groups and was excluded from all trend tests."

DNA damage from exposure to RFR was assessed in frontal cortex, hippocampus, cerebellum, liver, blood, and heart cell samples from male mice and male and female rats using the comet assay (Table D-1, Table D-2, Table D-3, and Table D-4). For CDMA male mice, there were no significant increases in DNA damage, measured as the percent tail DNA, in cells sampled from the three brain regions, blood, and heart tissue; there was a significant trend test for the percent tail DNA in liver cells that is of uncertain biological significance. For CDMA male and CDMA female rats, no significant increases in the percent tail DNA were observed for any tissue. For GSM male rats, there were no significant increases in DNA damage, measured as the percent tail DNA, in cells sampled from frontal cortex, cerebellum, liver, blood, or heart tissue; there was a significant trend test for the percent tail DNA in hippocampal cells that is of uncertain biological significance.

4.4 Summary: "Five-day studies were conducted in male mice or male or female rats to evaluate the effect of exposure to the same CDMA- or GSM-modulated RF signals used in the previous NTP studies. Video from the cameras in the exposure chambers demonstrated no consistent, exposure-related, and visible changes in activity in either rats or mice the first time the exposure system was activated, at subsequent system on/off transitions, or during the periods of exposure. There were no exposure-related effects on survival or body weights following exposure to RFR for 5 days. There was no increase in DNA damage following exposure to RFR for 5 days, as measured using the comet assay, in brain cells (frontal cortex, hippocampus, and cerebellum), or in liver, heart, or blood cells of mice and rats. Body temperature measurements were collected during the studies using two different devices; however, the data were unusable."

Conclusions

"The studies reported herein were conducted by researchers in the Division of Translational Toxicology (DTT) at the National Institute of Environmental Health Sciences (NIEHS). These studies were not conducted as part of the National Toxicology Program."

"The new small-scale RFR exposure system described in this report was developed by NIEHS/DTT to overcome those limitations with a signal generator capable of generating a broader array of RF signals. In addition to the GSM and CDMA signals at 900 and 1,900 MHz used in the previous NTP studies, the small-scale exposure system could generate signals reflective of more current wireless communications (e.g., Third Generation Partnership Project [3GPP] LTE Frequency Division Duplex [FDD] and Time Division Duplex [TDD], LTE-Advanced, 3GPP FDD/ High-Speed Packet Access [HSPA]/HSPA+, GSM/Enhanced Data rates for GSM Evolution [EDGE]/EDGE Evolution, Time Division-Synchronous CDMA [TD-Whole-body Radiofrequency Radiation SCDMA], Wireless Local-area Network [WLAN]) with frequencies between 9 kHz and 3.2 GHz, modulations with base bandwidths of up to 120 MHz, and carrier frequencies of up to 3,200 MHz."

"In these studies, evaluation of video from the cameras in the exposure chambers demonstrated no consistent, exposure-related, and visible changes in activity in either rats or mice the first time the system was activated, during subsequent system on/off transitions, or during the periods of exposure."

"Equivocal results, showing limited statistically significant effects, were observed for male mouse liver cells (CDMA) and male rat hippocampal cells (GSM) in these 5-day studies. Although it is not possible to directly compare the 5-day and 90-day comet assay studies, it is interesting to note that a positive result for hippocampal cells from male rats exposed to CDMA was observed in the 90-day study."

"High-quality studies to understand the effects of RFR exposure on biological responses are needed given the widespread human exposure to RFR associated with cell phone use."

Excerpts from tables with statistically significant tests of trends for DNA damage




Table D-1. DNA Damage in Male Mice Exposed to Whole-body CDMA-modulated Cell Phone Radiofrequency Radiation for Five Days



Open access report: https://www.niehs.nih.gov/sites/default/files/2025-08/cellphonerfr_long_508.pdf

https://www.niehs.nih.gov/research/atniehs/dtt/assoc/reports/cellphonerfr