Health impact of 5G: Current state of knowledge of 5G-related carcinogenic and reproductive/developmental hazards as they emerge from epidemiological studies and in vivo experimental studies
Fiorella Belpoggi. Health impact of 5G: Current state of knowledge of 5G-related carcinogenic and reproductive/developmental hazards as they emerge from epidemiological studies and in vivo experimental studies. Panel for the Future of Science and Technology. European Parliamentary Research Service. Scientific Foresight Unit (STOA). PE 690.012. June 2021.
The upcoming deployment of 5G mobile networks will allow for significantly faster mobile broadband speeds and increasingly extensive mobile data usage. Technical innovations include a different transmission system (MIMO: use of multiple‐input and multiple‐output antennas), directional signal transmission or reception (beamforming), and the use of other frequency ranges. At the same time, a change is expected in the exposure to electromagnetic fields (EMF) of humans and the environment. In addition to those used to date, the 5G pioneer bands identified at EU level have frequencies of 700 MHz, 3.6 GHz (3.4 to 3.8 GHz) and 26 GHz (24.25 to 27.5 GHz). The first two frequencies (FR1) are similar to those used for 2G to 4G technologies and have been investigated in both epidemiological and experimental studies for different end points (including carcinogenicity and reproductive/developmental effects), while 26 GHz (FR2) and higher frequencies have not been adequately studied for the same end points.
The International Agency for Research on Cancer (IARC) classified radiofrequency (RF) EMF as ‘possibly carcinogenic to humans’ (Group 2B) and recently recommended RF exposure for re-evaluation ‘with high priority’ (IARC, 2019). Since 2011 a great number of studies have been performed, both epidemiological and experimental. The present review addresses the current knowledge regarding both carcinogenic and reproductive/ developmental hazards of RF as exploited by 5G. There are various in vivo experimental and epidemiological studies on RF at a lower frequency range (450 to 6000 MHz), which also includes the frequencies used in previous generations’ broadband cellular networks, but very few (and inadequate) on the higher frequency range (24 to 100 GHz, centimetre/MMW).
The review shows: 1) 5G lower frequencies (700 and 3 600 MHz): a) sufficient evidence of carcinogenicity in epidemiological studies; b) sufficient evidence of carcinogenicity in experimental bioassays; c) sufficient evidence of reproductive/developmental adverse effects in humans; d) sufficient evidence of reproductive/ developmental adverse effects in experimental animals; 2) 5G higher frequencies (24.25-27.5 GHz): the systematic review found no adequate studies either in humans or in experimental animals.
Conclusions: 1) cancer: FR1 (450 to 6 000 MHz): EMF are probably carcinogenic for humans, in particular related to gliomas and acoustic neuromas; FR2 (24 to 100 GHz): no adequate studies were performed on the higher frequencies; 2) reproductive developmental effects: FR1 (450 to 6 000 MHz): these frequencies clearly affect male fertility and possibly female fertility too. They may have possible adverse effects on the development of embryos, foetuses and newborns; FR2 (24 to 100 GHz): no adequate studies were performed on non-thermal effects of the higher frequencies.
Recent decades have seen an unparalleled development of technologies known as information and communications technologies (ICT), which include wireless communication used for mobile telephones and, for example, Wi-Fi using radiofrequency (RF) electromagnetic fields (EMF).
The first generation of handheld mobile phones was available in the late 1980s.
Subsequently, the second (2G), third (3G) and fourth (4G, long-term evolution = LTE) generations dramatically increased their penetration rates in society, so that today in Europe there are more devices than inhabitants. In addition, Wi-Fi and other forms of wireless data transfer have become ubiquitous and are globally available. Nevertheless, there are new inequalities in terms of access to high-speed internet (even within high-income countries) and control by authoritarian regimes shows risks for democracy and European values.
The introduction of the next generation of RF, 5G, has begun on mobile networks. 5G is not a wholly new technology, but an evolution of already existing G1 to G4 technologies. 5G networks will work within several different frequency bands, the lower frequencies of which are being proposed for the first phase of 5G networks. Several of these frequencies have been or are currently being used for earlier mobile communication generations. There are also plans to use much higher radio frequencies at later stages of the 5G technology evolution. The new bands are well above the ultra high frequency (UHF) range, having wavelengths in the centimetre (3–30 GHz) or millimetre ranges (MMW) at 30-300 GHz. These latter bands have traditionally been used for radar and microwave links and very few have been studied for their impact on human health.
This review of the currently available scientific evidence focuses on both the carcinogenic and the reproductive/developmental effects of RF from mobile phone telecommunications systems using 2G-5G networks, based on both in vivo animal studies and human epidemiological studies. The studies evaluated have been divided into two groups:
1) studies evaluating health effects due to RF at the lower frequency range (FR) (FR1: 450 to 6000 MHz), which also includes the frequencies used in the existing 2-4 generations of the broadband cellular network. The current evidence from 2G-4G studies is the best evidence currently available. The studies were evaluated using narrative methods;
2) studies evaluating health effects due to RF at the higher FR (FR2: 24 to 100 GHz – MMW). The higher frequencies are new, not previously used for mobile communication and specific to the new 5G technology, which has particular physical characteristics and interactions with biological matter (lower penetration, higher energy, etc.): they were considered separately using a scoping review method.
Narrative review (FR1) will be distinguished from scoping review (FR2), but the selection and assessment criteria indicated for scoping reviews were adopted for both searches and for including/excluding studies on the cancer and reproductive/developmental biological end points.
In finally assessing the results of both epidemiological and experimental study, and of cancer and reproductive/developmental outcomes, consideration was given to the parameters indicated in the IARC Monograph Preamble (2019), tailored to the needs of the present report, and valid for both end points (i.e. cancer and reproductive/developmental effects):
Sufficient evidence: a causal association between exposure to RF-EMF and the specific adverse effect has been established. That is, a positive association has been observed in the body of evidence on exposure to the agent and the specific adverse effect in studies in which chance, bias, and confounding factors were ruled out with reasonable confidence.
Limited evidence: a causal interpretation of the positive association observed in the body of evidence on exposure to RF-EMF and the specific adverse effect is credible, but chance, bias, or confounding factors cannot be ruled out with reasonable confidence.
No evidence: there are no data available or evidence, suggesting lack of adverse effects (to be specified).
The overall evaluation for both cancer and reproductive/developmental effects was obtained by the integration of the human/animal evidence as follows:
3. Exposure assessment
The question of exposure assessment with the introduction of 5G is complicated, above all concerning the monitoring of the continuous changes in activity of both base stations (BS) and user equipment (UE) related to MIMO (multiple input, multiple output) technology. Furthermore, the technical approach to exposure assessment in the future scenario, relating to 1G, 2G, 3G, 4G and 5G concurrent emissions, is still being formulated and is hence uncertain.
4. Non-thermal effects
The harmful effects of non-thermal biological interaction of RF-EMF with human and animal tissues have not been included in the determination of the ICNIRP 2020 guidelines (ICNIRP 2020a), despite the huge amount of available scientific publications demonstrating the harmfulness or potential harmfulness of those effects. Athermal bioresponses exist, and indeed some frequencies are being used for therapeutic purposes in a number of branches of medicine. Any drug, as we well know, even the most beneficial, may also entail some adverse effects. So, thermal as well as non-thermal effects of RF-EMF have to be considered in risk assessment.
5. State of the art of the research on RF-EMF
The introduction of wireless communication devices that operate in the RF region of the electromagnetic spectrum (450 to 6000 MHz, lower frequencies) has triggered a considerable number of studies focusing on health concerns. These studies encompass studies on humans (epidemiological), on animals (rodent experimental studies), and on in-vitro cellular systems.
5G networks will increase the number of wireless devices, necessitating a lot more infrastructure, so as to allow for a higher mobile data volume per geographic area. Moreover, it is necessary to build up increased network density, as the higher frequencies required for 5G (24 to 100 GHz, MMW) have shorter ranges. The studies available on these frequencies are few in number and of mixed quality.
This raises the questions as to whether these higher frequencies would have health and environmental effects different from those at lower frequencies. Worldwide, assessments of RF safety have been performed at different levels, with the publication of scientific and policy papers.
With regard to cancer, the IARC 2011 analysis of the literature reviewed up to 2011 (Baan, 2011), published in 2013, and cited throughout as IARC (2013), defined RF-EMF in the frequency range from 30 kHz to 300 GHz as ‘possibly carcinogenic’ to humans, based on ‘limited evidence of carcinogenicity’ in human and in experimental animals. The studies available in 2011 examined RF in the range we here call FR1, that is from 450 to 6 000 MHZ. The FR2 frequencies (24 to 100 GHz) lie in the MMW range.
The IARC 2011 analysis evaluated RF-EMF. While there were no studies on 5G, some studies on high frequency occupational radar and microwave exposures were included.
The new MMW frequencies (FR2: 24 to 100 GHz) will be added to the lower frequencies already in use including in part by 5G. It follows that, for 5G in the range 450 to 6000 MHz (FR1) there are many studies, many collected in the IARC Monograph in relation to cancer, while for 26 GHz and other MMW frequencies in general there is little literature exploring the possible adverse effects on health. The simple reason for this is that hitherto these frequencies have never been used for mass communication and hence there were few suitable populations exposed to these frequencies to study; there are likewise very few adequate studies on non-thermal effects on laboratory animals.
6. Results of the present review
Using PubMed and the EMF Portal database, and applying the scoping review methodology to our research, we found 950 papers on the carcinogenicity of RF-EMF in humans, and 911 papers on experimental rodent studies, totalling 1861 studies. Regarding reproductive/developmental studies, we found 2834 papers for epidemiology and 5052 studies for experimental rodent studies, totalling 7886 studies. From the present review of the literature and the considerations reported above, we come to the following conclusions:
6.1 Cancer in humans
FR1 (450 to 6000 MHz): there is limited evidence for carcinogenicity of RF radiation in humans. Updating the results of the overall 2011 evaluation to 2020, positive associations have again been observed between exposure to radiofrequency radiation from wireless phones and both glioma (tumour of the brain) and acoustic neuroma, but the human evidence is still limited.
FR2 (24 to 100 GHz): no adequate studies were performed on the effects of the higher frequencies.
6.2 Cancer in experimental animals
FR1 (450 to 6000 MHz): there is sufficient evidence in experimental animals of the carcinogenicity of RF radiation. New studies following the 2011 IARC evaluation showed a positive association between RF-EMF and tumours of the brain and Schwann cells of the peripheral nervous system, the same type of tumours also observed in epidemiological studies.
FR2 (24 to 100 GHz): no adequate studies were performed on the higher frequencies.
6.3 Reproductive/developmental effects in humans
FR1 (450 to 6 000 MHz): there is sufficient evidence of adverse effects on the fertility of men. There is limited evidence of adverse effects on fertility in women. There is limited evidence of developmental effects in offspring of mothers who were heavy users of mobile phones during pregnancy.
FR2 (24 to 100 GHz): no adequate studies were performed on the higher frequencies.
6.4 Reproductive/developmental effects in experimental animals
FR1 (450 to 6000 MHz): there is sufficient evidence of adverse effects on male rat and mouse fertility. There is limited evidence of adverse effects on female mouse fertility. There is limited evidence of adverse effects on the development in offspring of rats and mice exposed during embryo life.
FR2 (24 to 100 GHz): no adequate studies on non-thermal effects were performed on the higher frequencies.
7. Overall evaluation
FR1 (450 to 6000 MHz): these FR1 frequencies are probably carcinogenic to humans.
FR2 (24 to 100 GHz): no adequate studies were performed on the higher frequencies.
7.2 Reproductive/developmental effects
FR1 (450 to 6000 MHz): these frequencies clearly affect male fertility. They possibly affect female fertility. They possibly have adverse effects on the development of embryos, foetuses and newborns.
FR2 (24 to 100 GHz): no adequate studies were performed on non-thermal effects of the higher frequencies.
8. Policy options
8.1 Opting for novel technology for mobile phones that enables RF-EMF exposures to be reduced
The sources of RF emissions that seem at present to pose the greatest threat are mobile phones. Though transmitting installations (radio base masts) are perceived by some people as providing the greatest risk, actually the greatest burden of exposure in humans generally derives from their own mobile phones, and epidemiological studies have observed a statistically significant increase in brain tumours and Schwann cell tumours of the peripheral nerves, mainly among heavy cell-phone users.
Accordingly, action is needed to ensure that safer and safer telephone devices are manufactured, emitting low energy and if possible only working when at a certain distance from the body. The cable earpiece solves much of the problem but is inconvenient and hence puts users off; on the other hand, it is not always possible to use speakerphone mode. The option of lowering RF-EMF exposure as much as possible in connection with telephones still applies whatever the frequencies being used, from 1G to 5G. Countries such as the US and Canada, which enforced stricter mobile phone SAR limits than in Europe, were still able to build efficient 1G,2G, 3G, 4G communications (Madjar, 2016). Since 5G aims to be more energy-efficient than the previous technologies, adopting stricter limits in the EU for mobile phone devices would be at once a sustainable and a precautionary approach.
8.2 Revising exposure limits for the public and the environment in order to reduce RF-EMF exposure from cell towers
Recently, EU policies (European Commission, 2019) have promoted the sustainability of a new economic and social development model that uses new technologies to constantly monitor the planet’s state of health, including climate change, the energy transition, agro-ecology and the preservation of biodiversity. Using the lowest frequencies of 5G and adopting precautionary exposure limits such as those used in Italy, Switzerland, China, and Russia among others, which are significantly lower than those recommended by ICNIRP, could help achieve these EU sustainability objectives.
8.3 Adopting measures to incentivise the reduction of RF-EMF exposure
Much of the remarkable performance of the new wireless lower frequency 5G technology can also be achieved by using optic-fibre cables and by adopting engineering and technical measures to reduce exposure from 1-4G systems (Keiser, 2003; CommTech Talks, 2015; Zlatanov, 2017). This would minimise exposure, wherever connections are needed in fixed sites. For example, optic fibre cables could be used to connect schools, libraries, workplaces, houses, public buildings, and all new buildings etc., and public gathering places could be ‘no RF-EMF’ areas (along the lines of no-smoking areas) so as to avoid the passive exposure of people not using a mobile phone or long-range transmission technology, thus protecting many vulnerable elderly or immune-compromised people, children, and those who are electro-sensitive.
8.4 Promoting multidisciplinary scientific research to assess the long-term health effects of 5G and to find an adequate method of monitoring exposure to 5G
The literature contains no adequate studies that would rule out the risk that tumours and adverse effects on reproduction and development may occur upon exposure to 5G MMW, or to exclude the possibility of some synergistic interactions between 5G and other frequencies that are already being used. This makes the introduction of 5G fraught with uncertainty concerning both health issues and forecasting and or monitoring the actual exposure of the population: these gaps in knowledge justify the call for a moratorium on MMW of 5G, pending completion of adequate research.
In light of these uncertainties, one policy option is to promote multidisciplinary team research into various factors concerning exposure assessment and also into the biological effects of 5G MMW at frequencies between 6 and 300 GHz, both on humans and on the flora and fauna of the environment, e.g. non-human vertebrates, plants, fungi, and invertebrates.
MMW will only be brought in with the final 5G protocol, i.e. not until three to five years’ time. Given this time frame, one option is to study their effects before exposing the whole world population and environment.
Implementing MMW 5G technology without further preventive studies would mean conducting an ‘experiment’ on the human population in complete uncertainty as to the consequences. To restrict our scope to Europe, this could occur within a field like that of chemistry, currently governed by REACH (EC, 1907/2006).
REACH aims to improve the protection of human health and the environment through better and earlier identification of the intrinsic properties of chemical substances. EU REACH regulates the registration, evaluation, authorisation, and restriction of chemicals. It also aims to enhance the innovation and competitiveness of the EU chemicals industry. EU REACH is based on the principle of ‘no data, no market’, placing responsibility on industry to provide safety information on substances.
Manufacturers and importers are required to gather information on the properties of their chemical substances, which will allow their safe handling, and to register the information in a central database in the European Chemicals Agency (ECHA). One policy option can be to apply the same approach to all types of technological innovation.
The results of these studies could form the basis for developing evidence-based policies regarding RF-EMF exposure of human and non-human organisms to 5G MMW frequencies. Further studies are needed to better and independently explore the health effects of RF-EMF in general and of MMW in particular.
8.5 Promoting information campaigns on 5G
There is a lack of information on the potential harms of RF-EMF. The information gap creates scope for deniers as well as alarmists, giving rise to social and political tension in many EU countries. Public information campaigns should therefore be a priority.
Information campaigns should be carried out at all levels, beginning with schools. People should be informed of the potential health risks, but also the opportunities for digital development, what infrastructural alternatives exist for 5G transmission, the safety measures (exposure limits) taken by the EU and Member States, and the correct use of mobile phones. Only with sound and accurate information can we win back citizen trust and reach a shared agreement over a technological choice which, if properly managed, can bring great social and economic benefits.
“’Significant concern is emerging over the possible impact on health and safety arising from potentially much higher exposure to radiofrequency electromagnetic radiation arising from 5G. Increased exposure may result not only from the use of much higher frequencies in 5G but also from the potential for the aggregation of different signals, their dynamic nature, and the complex interference effects that may result, especially in dense urban areas. The 5G radio emission fields are quite different to those of previous generations because of their complex beamformed transmissions in both directions – from base station to handset and for the return. Although fields are highly focused by beams, they vary rapidly with time and movement and so are unpredictable, as the signal levels and patterns interact as a closed loop system. This has yet to be mapped reliably for real situations, outside the laboratory’ (Blackman and Forge, 2019).”
“Regarding exposure assessment, Neufeld and Kuster (2018) issued a warning in a paper in Health Physics, urging that existing exposure standards be revised with shorter averaging times to address potential thermal damage from short and strong pulses: “Extreme broadband wireless devices operating above 10 GHz may transmit data in bursts of a few milliseconds to seconds. Even though the time- and area-averaged power density values remain within the acceptable safety limits for continuous exposure, these bursts may lead to short temperature spikes in the skin of exposed people. … [Our] results also show that the peak-to-average ratio of 1,000 tolerated by the ICNIRP guidelines may lead to permanent tissue damage after even short exposures, highlighting the importance of revisiting existing exposure guidelines” (Neufeld and Kuster, 2018).”
“This study has been written by Dr Fiorella Belpoggi, BSC, PhD, International Academy of Toxicologic Pathology Fellow (IATPF), Ramazzini Institute, Bologna (Italy), at the request of the Panel for the Future of Science and Technology (STOA) and managed by the Scientific Foresight Unit, within the Directorate-General for Parliamentary Research Services (EPRS) of the Secretariat of the European Parliament.
The scoping review search was performed by Dr Daria Sgargi, PhD, Master in Biostatistics, and Dr Andrea Vornoli, PhD in Cancer Research, Ramazzini Institute, Bologna.
The author thanks Dr Daniele Mandrioli, MD, PhD, Ramazzini Institute, Bologna (Italy), who advised and reviewed the methodology; Prof. Carlo Foresta, MD, and Prof. Andrea Garolla, MD, Professors of Endocrinology and Andrology, University of Padua (Italy), who critically reviewed the results on reproductive adverse effects in humans; Prof. Fausto Bersani, Physicist, Consultant, Rimini (Italy), who assisted her in the interpretation of papers regarding the exposure scenario.”
Environmental impacts of 5G: A literature review of effects of radio-frequency electromagnetic field exposure of non-human vertebrates, invertebrates and plants
Arno Thielens. Environmental impacts of 5G: A literature review of effects of radio-frequency electromagnetic field exposure of non-human vertebrates, invertebrates and plants. Panel for the Future of Science and Technology (STOA). European Parliament. 2021, 137 pp. PE 690.021, ISBN 9789284680337. doi: 10.2861/318352.
Telecommunication networks use radio-frequency electromagnetic fields to enable wireless communication. These networks have evolved over time, and have been launched in successive generations. The fifth generation of telecommunication networks will operate at frequencies that were not commonly used in previous generations, changing the exposure of wildlife to these waves. This report reviews the literature on the exposure of vertebrates, invertebrates and plants to radio-frequency electromagnetic fields in anticipation of this change.
The review shows that dielectric heating can occur at all considered frequencies (0.4-300 GHz) and for all studied organisms. Summarising and discussing the results of a series of studies of radio-frequency electromagnetic field exposure of wildlife, the review shows that several studies into the effects of radio-frequency electromagnetic field exposure on invertebrates and plants in the frequency bands considered demonstrate experimental shortcomings. Furthermore, the literature on invertebrate and plant exposure to radio-frequency electromagnetic fields above 6 GHz is very limited. More research is needed in this field.
Wireless telecommunication is a widespread technology that uses radio-frequency (RF) electromagnetic fields (EMFs) to send information between users. Wildlife can be exposed to these waves, which will partially penetrate biological tissues. These internal fields can have biological effects. Exposure to RF-EMFs and the interaction between the EMFs and organisms will depend on the frequency of the waves. Fifth generation wireless telecommunication networks (5G) will be operating partly at new frequencies that are not very commonly found in the environment. These anticipated changes warrant a review of the existing literature on the effects of RF-EMF exposure of wildlife. This study presents such a review.
A database search of the current literature in the field found that it is subdivided based on two classifiers. The first is the target group investigated: non-human vertebrates, invertebrates and plants; the second is the RF-EMF frequency studied, which is subdivided between a lower (0.45-6 GHz) and a higher frequency range (6-300 GHz). The former frequency range includes those frequencies where the current telecommunication networks operate, while the latter is the range in which 5G will partially operate. This resulted in six categories, which are reviewed separately.
Dielectric heating due to RF-EMF exposure of biological tissue is shown in all categories. This heating causes internal temperature increases in organisms or cells, which in turn has biological effects such as a thermoregulatory response. This implies that there is always a level of RF-EMF power density that will cause biological effects, referred to as thermal effects. Decoupling effects caused by elevated temperatures and the presence of RF-EMFs within biological tissue are major issues in this field of study.
Many studies focus on demonstrating (the absence of) non-thermal effects. These are effects that are caused by RF-EMF exposure but are not associated with any changes in temperature. A wide variety of other effects of RF-EMF exposure are studied. However, no effect, apart from dielectric heating, is studied in all six categories.
Lower frequency range (0.45-6 GHz)
In the lower frequency range, in vitro studies on non-human vertebrate cells showed mixed results on cellular genotoxicity and cellular transformation under RF-EMF exposure. Previous reviews on these subjects conclude either that the evidence for such effects is weak or that the literature is inconclusive. Regarding non-genotoxic effects of RF-EMF exposure, there are reports claiming that neural activity can be altered in vitro through RF-EMF exposure. Other cellular effects are either not proven or contested, or there are not enough studies to come to any conclusions on such effects. In vivo studies on genotoxicity of RF-EMFs found contradictory results. There is a debate in the literature on whether RF-EMF exposure can induce (transient) changes in the permeability of the blood-brain barrier.
It seems that the most recent studies could not show such effects. There are mixed results regarding the in vivo effects of RF-EMF exposure on the neural system. There seems to be a consensus that animals can hear (pulsed) RF-EMFs above a certain threshold, so-called microwave hearing. However, there is little evidence that telecommunication signals can induce this effect. Environmental studies on RF-EMF exposure and vertebrate behaviour focus mainly on animal nesting, reproduction, orientation and abundance near RF-EMF sources. There are a limited number of studies that conclude that behavioural and reproductive effects might occur for birds and bats under RF-EMF exposure.
RF-EMF exposure of invertebrates in the lower frequency range has been studied by several authors. In addition to dielectric heating, there is a focus on developmental, genetic, or behavioural effects. In vitro studies have shown increased neural activity in invertebrate neurons. In vivo studies on invertebrates are faced with several experimental problems and present inconclusive results on a series of investigated parameters. More research of higher quality, sham-exposed control groups is necessary. As for the limited number of studies that investigated non-insect invertebrates, they all found effects (in vitro and in vivo). This calls for more research on this topic. A very limited number of environmental studies focus on invertebrates and studies on non-insect invertebrates are under-represented as well. These topics require more research in the future.
Plants and fungi
Dielectric heating of plants has been shown in the lower frequency range. This heating might have beneficial effects, but will also induce plant mortality at a certain level. At lower levels of RF-EMF exposure, the literature on plants and fungi shows contradictory results and is plagued by experimental shortcomings. The numbers of studies and plants studied, especially for fungi, is limited in comparison to those studies that focus on animals. More research in this area is necessary, and should focus on a higher quality of unexposed control and sham control groups, temperature and exposure monitoring, and dosimetry.
Higher frequency range (6 to 300 GHz)
In the higher frequency range, in vitro studies on both vertebrate and invertebrate neurons have shown effects of RF-EMF exposure on neural activity. In vivo studies on vertebrates have shown that RF-EMF exposure of the eye can induce corneal lesions and cataract. Effects on male fertility have been demonstrated in rodents as well. Mixed results of RF-EMF exposure on behaviour and prevalence of vertebrates are found. One research group demonstrated that RF-EMF exposure can have a hypoalgesic effect in mice. These effects should be replicated by other research groups. There is some evidence that high-frequency RF-EMFs can be used to induce an anti-inflammatory response, up to a certain dosage. A limited number of in vivo studies have shown that high-frequency RF-EMFs can reduce tumor growth.
In the same frequency range, there have been in vitro demonstrations of neurostimulation and in vivo demonstration of developmental and teratogenic effects on invertebrates at relatively high power-densities. These effects should be investigated further at lower power densities. The literature on invertebrate exposure to RF-EMFs in this frequency range is limited and warrants further investigation.
Plants and fungi
The literature on fungi and plants in the higher frequency range is very limited and no conclusions besides the existence of dielectric heating can be drawn at this moment. It is necessary to execute further research in this area.
Dielectric heating due to RF-EMF exposure is shown in all categories studied.
In the lower frequency range (0.45-6 GHz), the majority of the existing literature focuses on vertebrates, for which a series of potential effects are studied. Those studies that investigate RF-EMF exposure of invertebrates in the lower frequency range focus on dielectric heating, and developmental, genetic or behavioural effects. Literature on non-insect invertebrates is very limited. Studies on plant exposure in the lower frequency range, which target exposure outcomes at plant level show experimental shortcomings. The number of studies in this category is limited in comparison to those studies that focus on animals.
In the higher frequency range (6-300 GHz) the number of peer-reviewed publications is in general lower than in the lower frequency range. For vertebrates, a series of potential exposure outcomes are studied, while the literature on invertebrates and plants above 6 GHz is very limited. More research in this field is necessary.
5. Policy options
Given the results of this review, four policy options were formulated.
A first policy option could be to fund research on RF-EMF exposure of plants, fungi and invertebrates at frequencies below 6 GHz and to fund research on non-human vertebrates, plants, fungi and invertebrates at frequencies of between 6 and 300 GHz. These studies could form the basis for evidence-based policies regarding RF-EMF exposure of non-human organisms.
A second policy option could be to call for systematic monitoring of environmental RF-EMFs, since these are the main source of exposure for non-human organisms and it is expected that this exposure will change over time.
A third policy option could be a request to make information on the RF-EMF operational aspects of the telecommunication networks public. This would again be aimed at quantifying
environmental RF-EMF exposure over time.
A fourth policy option could be to require compliance studies for organisms other than humans when base station antennas are installed in the telecommunication network. This would prevent the excessive RF-EMF exposure of non-human organisms near such antennas.