Report of the Advisory Group to Recommend Priorities for the IARC Monographs during 2025–2029
Radiofrequency electromagnetic fields including wireless mobile radiation (pp. 171-173)
Current IARC/WHO classification
Radiofrequency electromagnetic field (RF-EMF) radiation (including from wireless mobile telephones) has been previously classified by IARC as possibly carcinogenic to humans (Group 2B) in IARC Monographs Volume 102 in 2011 (IARC, 2013a), based on limited evidence in humans for glioma and acoustic neuroma. RF-EMF was given a priority rating of high by the Advisory Group to Recommend Priorities for the IARC Monographs during 2020–2024 (IARC, 2019a), on the basis of new cancer bioassay evidence in two independent studies (described below).
WHO is undertaking a health risk assessment of RF-EMF for a variety of outcomes, including cancer. This will be published as a monograph in the Environmental Health Criteria series and is based on several, currently ongoing, systematic reviews commissioned by WHO (Lagorio et al., 2021; Mevissen et al., 2022).
Exposure characterization
In IARC Monographs Volume 102, RF-EMF radiation was defined as radiation in the frequency range 30 kHz to 300 GHz (IARC, 2013a). Exposure occurs in the general population and in occupational settings, with sources including mobile phones, wireless network, television, radio, 5G technologies, Bluetooth, microwaves, cooking hobs, industrial heating of materials, radar, anti-theft devices, and MRI (IARC, 2013a). Exposure to mobile phones is ubiquitous, considering that nearly 95% of the population in high-income countries and 49% in low-income countries own a mobile phone (International Telecommunications Union, 2022). Source-exposure matrices for the general population and workers are available (Vila et al., 2016; van Wel et al., 2021).
Cancer in humans
The 2019 Advisory Group report (IARC, 2019a) indicated that results from epidemiological studies published after IARC Monographs Volume 102 were mixed (Benson et al., 2013; Hardell et al., 2013; Coureau et al., 2014; IARC, 2019a; Röösli et al., 2019). Since the 2019 Advisory Group report (IARC, 2019a), results from the MOBI-Kids study, an international study of brain cancer and the use of EMF technology by children and adolescents (Castaño-Vinyals et al., 2022), the update of the UK Million Women Study (Schüz et al., 2022), and the European Cohort Study of Mobile Phone Use and Health (COSMOS) (Feychting et al., 2024) were published. No increased risk of neuroepithelial brain tumour was found in the MOBI-Kids study (Castaño-Vinyals et al., 2022). In the Million Women Study update, the increased risk for acoustic neuroma reported previously (10+ years use versus never, RR, 2.46; 95% CI, 1.07–5.64) (Benson et al., 2013) was attenuated (10+ years use versus never, RR, 1.32; 95% CI, 0.89–1.96), and no increased risk was found for other cancer subtypes (glioma, glioblastoma, pituitary, eye tumour); however, the exposure assessment was crude. The previous analysis (Benson et al., 2013) reported Ptrend = 0.03 for acoustic neuroma by duration of use, but such an analysis was not reported in the updated publication (Schüz et al., 2022). COSMOS followed 264 574 participants for a median of 7.12 years (recruitment, 2007–2012, in Denmark, Finland, the Netherlands, Sweden, and the UK). For 100 regression-calibrated cumulative hours of calls (country-specific regression-calibrated estimates based on data collected from operators were applied to the self-reported measurements), HRs were 1.00 (95% CI, 0.98–1.02) for glioma, 1.01 (95% CI, 0.96–1.06) for meningioma, and 1.02 (95% CI, 0.99–1.06) for acoustic neuroma (Feychting et al., 2024).
Mobile phone use was associated with increases in overall cancer and NMSC, urinary cancer (in men only), prostate cancer, and vulva cancer, but not brain cancer, in the UK Biobank cohort (Zhang et al., 2024). There was also a significant trend by length of use for NMSC and prostate cancer (Zhang et al., 2024) Concern exists over exposure misclassification, as mobile phone use was captured only at baseline. These findings are not consistent with those of a Danish nationwide cohort study (Schüz et al., 2006).
In IARC Monographs Volume 102 (IARC, 2013a), selection bias and recall bias from case–control studies were noted as being of major concern. Bias analysis available at the time of that evaluation showed that the J-shaped response curve observed in the Interphone study, the largest case–control study on mobile phone use contributing to the evidence published in IARC Monographs Volume 102 (IARC, 2013a), could have been explained by selection bias, leading to underrepresentation of unexposed controls (Vrijheid et al., 2009a). A recent bias analysis using Monte Carlo simulations showed that the J-shaped relation observed in the Interphone study was compatible with a scenario of greater systematic (> 10%) and random error in cases compared with controls, in the absence of any effect (Bouaoun et al., 2024). Validation studies within the Interphone study showed that there was little differential exposure misclassification between cases and controls; however, in heavy users, overestimation was greater in cases than in controls (Vrijheid et al., 2009b).
Cancer in experimental animals
The 2019 Advisory Group report (IARC, 2019a) noted the availability of new data from the large US NTP study that show clear evidence of an increased incidence of malignant schwannoma in the heart (and possibly some evidence of malignant glioma in the brain) in male rats exposed to radiofrequency radiation at frequencies used by mobile phones; however, no clear increased risk was seen in female rats. Some equivocal evidence was observed of increased evidence of malignant glioma in the brain, malignant schwannoma in the heart, and pheochromocytoma in the adrenal medulla (NTP, 2018a, b). An increased risk of schwannoma of the heart observed in male rats exposed to the highest dose was found in an experimental study conducted at the Ramazzini Institute (Falcioni et al., 2018). International studies, aimed to verify the NTP studies, are ongoing in Japan and the Republic of Korea and are expected in 2024 (Ahn et al., 2022). Currently, a systematic review of the effects of RF-EMF on cancer laboratory animals is ongoing as part of a WHO risk assessment project (Mevissen et al., 2022).
Mechanistic evidence
As noted in the 2019 Advisory Group report (IARC, 2019a): “The previous IARC evaluation concluded that there was weak evidence that radiofrequency radiation was genotoxic but that there was no evidence for mutagenicity (IARC, 2013a).” Since then, there have been many new publications on the genotoxicity of RF-EMF radiation, including studies in exposed humans. The formation of micronuclei on buccal mucosal cells was shown in several studies on mobile phone-emitted radiation (Rashmi et al., 2020; Revanth et al., 2020). Other studies found no evidence of micronucleus formation (de Oliveira et al., 2017) or no conclusive evidence for induction of DNA damage or for alterations of the DNA repair capacity in human cells exposed to several frequencies of RF-EMF radiation (Schuermann et al., 2020). In other studies, no effects of RF-EMF exposure on oxidant or antioxidant capacity, apoptosis, or mutations in the TP53 gene were revealed, regardless of the frequency (Khalil et al., 2014; Gulati et al., 2020). The authors of a meta-analysis to investigate whether RF-EMF emitted by mobile phones have genotoxic or cytotoxic effects on the oral epithelium concluded that the evidence for genotoxic effects was weak (Dos Santos et al., 2020). In experimental systems, there is a large body of literature on investigations of the genotoxicity of RF-EMF (Meltz, 2003). A study showed that rat gliomas appear to share some genetic alterations with IDH1 wildtype human gliomas, and rat cardiac schwannomas also harbour mutations in some of the queried cancer genes (Brooks et al., 2024). An independent systematic review of the genotoxicity of RF-EMF in in vitro mammalian models is ongoing (Romeo et al., 2021).
In addition, evidence associated with other KCs is available. For example, chronic exposure to RF-EMF emitted from mobile phones may induce oxidative stress and an inflammatory response in rats (Singh et al., 2020). Currently, a systematic review of the effects of RF-EMF on biomarkers of oxidative stress in vivo and in vitro is ongoing as part of the WHO risk assessment project (Henschenmacher et al., 2022). Several studies have investigated the immunotoxicity of RF-EMF (Yadav et al., 2022). Mobile phone radiofrequency radiation was found to be associated with thyroid gland insufficiency and alterations in serum thyroid hormone levels in exposed humans and in rodents, with a possible disruption in the hypothalamic–pituitary–thyroid axis (Alkayyali et al., 2021).
Summary
Since the last evaluation, there have been several new high-quality studies. Overall, the human cancer evidence is mixed. There is new evidence of carcinogenicity in experimental animals. Since the previous evaluation, there is new mechanistic evidence related to the KCs, especially genotoxicity in experimental systems and in exposed humans. However, several of the genotoxicity studies in exposed humans provided inconsistent results. Thus, the mechanistic available evidence currently available may be inconclusive.
Overall, the new evidence regarding cancer in humans and in experimental animals could support a re-evaluation, although a change in the current classification of the carcinogenicity of RF-EMF is uncertain. The Advisory Group therefore considered an IARC Monographs evaluation of RF-EMF to be warranted but suggests an evaluation in the latter half of the next 5 years, to await the results of ongoing cancer bioassays, which may provide additional mechanistic evidence.
Recommendation: High priority (and ready for evaluation within 5 years)
Open access report:
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In March, 2019, the Advisory Group for the IARC recommended that the IARC review the research on RFR to determine if it is a carcinogenic hazard (i.e. Group 2A or Group 1). The advisory group recommended that this review be conducted within the next five years and
called it a "high priority."
Following are excerpts from the IARC report:
International Agency for Research on Cancer (IARC). Report of the Advisory Group to Recommend Priorities for the IARC Monographs during 2020–2024. IARC, World Health Organization, 2019. https://monographs.iarc.fr/wp-content/uploads/2019/10/IARCMonographs-AGReport-Priorities_2020-2024.pdf.
Report of the Advisory Group to Recommend Priorities for the IARC Monographs during 2020–2024
Introduction (pp. 1-2)
"An IARC Advisory Group to Recommend Priorities for the IARC Monographs during 2020–2024 met in Lyon, France, on 25–27 March 2019. IARC periodically convenes such Advisory Groups to ensure that the Monographs evaluations reflect the current state of scientific evidence relevant to carcinogenicity.
The list of Advisory Group members and all other meeting participants is provided in Annex 1 (see https://monographs.iarc.fr/wp-content/uploads/2019/02/AGP-ListofParticipants.pdf ) ...."
"Priority was assigned on the basis of (i) evidence of human exposure and (ii) the extent of the available evidence for evaluating carcinogenicity (i.e. the availability of relevant evidence on cancer in humans, cancer in experimental animals, and mechanisms of carcinogenesis to support a new or updated evaluation according to the Preamble to the IARC Monographs). Any of the three evidence streams could alone support prioritization of agents with no previous evaluation. For previously evaluated agents, the Advisory Group considered the basis of the previous classification as well as the potential impact of the newly available evidence during integration across streams (see Table 4 in the Preamble to the IARC Monographs). Agents without evidence of human exposure or evidence for evaluating carcinogenicity were not recommended for further consideration."
....
"Non-ionizing radiation (radiofrequency) and extremely low-frequency magnetic fields (pp. 148-149)
Exposure Data
Human exposures to RF-EMF can occur from use of personal devices (e.g. cell phones, cordless phones, and Bluetooth) and from environmental sources such as cell phone base stations, broadcast antennas, and medical applications. More than 5 billion people now have access to cell phone devices, and the technology is constantly evolving. Use has also expanded rapidly in low- and middle-income countries, where more than 75% of adults now report owning a cell phone; in high-income countries, the proportion is 96% (Pew Research Center, 2018).
Cancer in Humans
Since the previous IARC Monographs evaluation, several new epidemiological studies have been published on the association between RF-EMF and cancer, although the evidence remains mixed. In the Million Women Study cohort, there was no evidence of increased risk of glioma or meningioma, even among long-term users. There was an increased risk of acoustic neuromas with long-term use and a significant dose–response relationship (Benson et al., 2013). Updated follow-up in the Danish nationwide subscribers study did not find increased risks of glioma, meningioma, or vestibular schwannoma, even among those with subscriptions of 10 years or longer (Frei et al., 2011; Schüz et al., 2011). New reports from case–control studies that assessed long-term use also found mixed results; for example, increased risks of glioma and acoustic neuroma were reported by Hardell & Carlberg (2015) and Hardell et al. (2013), but no evidence of increased risks for these tumours were reported by Yoon et al. (2015) and Pettersson et al. (2014). Röösli et al. (2019) recently reviewed these new data. Several large-scale studies are still in progress and should report results within the next few years. Mobi-Kids is a multicentre case–control study of brain tumours in those aged 10–24 years. Cohort Study of Mobile Phone Use and Health (COSMOS) is a new European cohort of adult cell phone users. There will also be updated results from the Million Women Study.
Cancer in Experimental Animals
New data in experimental animals for exposure to RF-EMF have been published since the previous IARC Monographs evaluation. The large study by the United States National Toxicology Program found an increased risk of malignant schwannomas of the heart in male rats with high exposure to radiofrequency radiation at frequencies used by cell phones, as well as possible increased risks of certain types of tumours in the brain and adrenal glands, but no increased risks in mice or female rats (NTP, 2018a, b). Another study in experimental animals also found an increase in schwannomas of the heart in highly exposed male rats and a possible increase in gliomas in female rats (Falcioni et al., 2018).
The previous IARC evaluation concluded that there was weak evidence that radiofrequency radiation was genotoxic but that there was no evidence for mutagenicity (IARC, 2013e). Although there have been many new publications from a wide variety of experiments, uncertainty remains about the mechanisms, and there are few systematic reviews of the new data (Kocaman et al., 2018).
Although a future evaluation could be broadened to consider exposure to all non-ionizing radiation (including ELF-MF), ELF-MF were evaluated by IARC as possibly carcinogenic to humans (Group 2B), and the Advisory Group did not recommend an update, because of a lack of new informative epidemiological findings, no toxicological evidence, and little supporting mechanistic evidence.
References
The following key references were also identified: Coureau et al. (2014); Carlberg & Hardell (2015); Pedersen et al. (2017).
Recommendation for non-ionizing radiation (radiofrequency): High priority (and ready for evaluation within 5 years)
Recommendation for extremely low-frequency magnetic fields: No evaluation "
References
cited in this section of the report:
Benson VS, Pirie K, Schüz J, Reeves GK, Beral V, Green J; Million Women Study Collaborators (2013). Mobile phone use and risk of brain neoplasms and other cancers: prospective study. Int J Epidemiol. 42(3):792–802. https://doi.org/10.1093/ije/dyt072 PMID:23657200
Carlberg M, Hardell L (2015). Pooled analysis of Swedish case-control studies during 1997-2003 and 2007-2009 on meningioma risk associated with the use of mobile and cordless phones. Oncol Rep. 33(6):3093–8. https://doi.org/10.3892/or.2015.3930 PMID:25963528
Coureau G, Bouvier G, Lebailly P, Fabbro-Peray P, Gruber A, Leffondre K, et al. (2014). Mobile phone use and brain tumours in the CERENAT case-control study. Occup Environ Med. 71(7):514–22. https://doi.org/10.1136/oemed-2013-101754 PMID:24816517
Falcioni L, Bua L, Tibaldi E, Lauriola M, De Angelis L, Gnudi F, et al. (2018). Report of final results regarding brain and heart tumors in Sprague-Dawley rats exposed from prenatal life until natural death to mobile phone radiofrequency field representative of a 1.8 GHz GSM base station environmental
Frei P, Poulsen AH, Johansen C, Olsen JH, Steding-JessenM, Schüz J (2011). Use of mobile phones and risk of brain tumours: update of Danish cohort study. BMJ. 343:d6387. https://doi.org/10.1136/bmj.d6387 PMID:22016439
Hardell L, Carlberg M (2015). Mobile phone and cordless phone use and the risk for glioma - analysis of pooled case-control studies in Sweden, 1997-2003 and 2007-2009. Pathophysiology. 22(1):1–13. https://doi.org/10.1016/j.pathophys.2014.10.001 PMID:25466607
IARC (2013e). Non-ionizing radiation, Part 2: Radiofrequency electromagnetic fields. IARC Monogr Eval Carcinog Risks Hum. 102:1–460. Available from: http://publications.iarc.fr/126 PMID:24772662
Kocaman A, Altun G, Kaplan AA, Deniz ÖG, Yurt KK, Kaplan S (2018). Genotoxic and carcinogenic effects of non-ionizing electromagnetic fields. Environ Res. 163:71–9. https://doi.org/10.1016/j.envres.2018.01.034 PMID:29427953
NTP (2018a). Toxicology and carcinogenesis studies in B6C3F1/N mice exposed to whole-body radio frequency radiation at a frequency (1900 MHz) and modulations (GSM and CDMA) used by cell phones. Natl Toxicol Program Tech Rep Ser. 596. Research Triangle Park (NC), USA: US Department of Health and Human Services, Public Health Service. Available from: https://ntp.niehs.nih.gov/ntp/htdocs/lt_rpts/tr596_508.pdf.
NTP (2018b). Toxicology and carcinogenesis studies in Hsd:Sprague Dawley SD rats exposed to whole-body radiofrequency radiation at a frequency (900MHz) and modulations (GSM and CDMA) used by cellphones. Natl Toxicol Program Tech Rep Ser. 595. Research Triangle Park (NC), USA: US Department of Health and Human Services, Public Health Service. Available from: https://www.niehs.nih.gov/ntp-temp/tr595_508.pdf.
Pedersen C, Poulsen AH, Rod NH, Frei P, Hansen J, Grell K, et al. (2017). Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers. Int Arch Occup Environ Health. 90(7):619–28. https://doi.org/10.1007/s00420-017-1224-0 PMID:28429106
Pettersson D, Mathiesen T, Prochazka M, Bergenheim T, Florentzson R, Harder H, et al. (2014). Long-term mobile phone use and acoustic neuroma risk. Epidemiology. 25(2):233–41. https://doi.org/10.1097/EDE.0000000000000058 PMID:24434752
Pew Research Center (2018). Social media use continues to rise in developing countries, but plateaus across developed ones. Available from: https://www.pewglobal.org/2018/06/19/social-media-use-continues-to-rise-in-developing-countries-but-plateaus-across-developed-ones/
Schüz J, Steding-JessenM, Hansen S, Stangerup SE, Cayé-Thomasen P, Poulsen AH, et al. (2011). Long-term mobile phone use and the risk of vestibular schwannoma: a Danish nationwide cohort study. Am J Epidemiol. 174(4):416–22. https://doi.org/10.1093/aje/kwr112 PMID:21712479
Straif K, Loomis D, Guyton K, Grosse Y, Lauby-Secretan B, El Ghissassi F, et al. (2014). Future priorities for the IARC Monographs. Lancet Oncol. 15(7):683–4. https://doi.org/10.1016/S1470-2045(14)70168-8
Yoon S, Choi J-W, Lee E, An H, Choi HD, KimN (2015). Mobile phone use and risk of glioma: a case-control study in Korea for 2002-2007. Environ Health Toxicol. 30:e2015015. https://doi.org/10.5620/eht.e2015015 PMID:26726040
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In May, 2011, the International Agency for Research on Cancer (IARC), the specialized cancer agency of the World Health Organization, classified radio frequency radiation (RFR) as "possibly carcinogenic to humans (Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use." "The conclusion means that there could be some risk, and therefore we need to keep a close watch for a link between cell phones and cancer risk."
A working group of 31 scientists from 14 nations made this determination after reviewing hundreds of studies that examined the potential carcinogenic hazard of long-term exposure to RFR. They examined exposure data, studies of cancer in humans, studies of cancer in experimental animals, and mechanistic and other relevant data.
IARC (2011). "IARC classifies radiofrequency electromagnetic fields as possibly carcinogenic to humans." Press Release No. 208. IARC, WHO. https://www.iarc.fr/wp-content/uploads/2018/07/pr208_E.pdf
IARC (2013e). Non-ionizing radiation, Part 2: Radiofrequency electromagnetic fields. IARC Monogr Eval Carcinog Risks Hum. 102:1–460. Available from: http://publications.iarc.fr/126 PMID:24772662
For a summary of this 2013 monograph see:
