Monday, March 21, 2022

Cancer risk from exposure to power lines and electrical appliances

Exposure to magnetic fields and childhood leukemia:
a systematic review and meta-analysis of case-control and cohort studies

Christian Brabant, Anton Geerinck, Charlotte Beaudart, Ezio Tirelli, Christophe Geuzaine and Olivier Bruyère. Exposure to magnetic fields and childhood leukemia: a systematic review and meta-analysis of case-control and cohort studies. Reviews on Environmental Health. Published online Mar 15, 2022. doi: 10.1515/reveh-2021-0112.

Abstract

The association between childhood leukemia and extremely low frequency magnetic fields (ELF-MF) generated by power lines and various electric appliances has been studied extensively during the past 40 years. However, the conditions under which ELF-MF represent a risk factor for leukemia are still unclear. Therefore, we have performed a systematic review and meta-analysis to clarify the relation between ELF-MF from several sources and childhood leukemia. We have systematically searched Medline, Scopus, Cochrane Database of Systematic Review and DARE to identify each article that has examined the relationship between ELF-MF and childhood leukemia. We have performed a global meta-analysis that takes into account the different measures used to assess magnetic field exposure: magnetic flux density measurements (<0.2 µT vs. >0.2 µT), distances between the child’s home and power lines (>200 m vs. <200 m) and wire codings (low current configuration vs. high current configuration). Moreover, meta-analyses either based on magnetic flux densities, on proximity to power lines or on wire codings have been performed. The association between electric appliances and childhood leukemia has also been examined. Of the 863 references identified, 38 studies have been included in our systematic review. Our global meta-analysis indicated an association between childhood leukemia and ELF-MF (21 studies, pooled OR=1.26; 95% CI 1.06–1.49), an association mainly explained by the studies conducted before 2000 (earlier studies: pooled OR=1.51; 95% CI 1.26–1.80 vs. later studies: pooled OR=1.04; 95% CI 0.84–1.29). Our meta-analyses based only on magnetic field measurements indicated that the magnetic flux density threshold associated with childhood leukemia is higher than 0.4 µT (12 studies, >0.4 µT: pooled OR=1.37; 95% CI 1.05–1.80; acute lymphoblastic leukemia alone: seven studies, >0.4 µT: pooled OR=1.88; 95% CI 1.31–2.70). Lower magnetic fields were not associated with leukemia (12 studies, 0.1–0.2 µT: pooled OR=1.04; 95% CI 0.88–1.24; 0.2–0.4 µT: pooled OR=1.07; 95% CI 0.87–1.30). Our meta-analyses based only on distances (five studies) showed that the pooled ORs for living within 50 m and 200 m of power lines were 1.11 (95% CI 0.81–1.52) and 0.98 (95% CI 0.85–1.12), respectively. The pooled OR for living within 50 m of power lines and acute lymphoblastic leukemia analyzed separately was 1.44 (95% CI 0.72–2.88). Our meta-analyses based only on wire codings (five studies) indicated that the pooled OR for the very high current configuration (VHCC) was 1.23 (95% CI 0.72–2.10). Finally, the risk of childhood leukemia was increased after exposure to electric blankets (four studies, pooled OR=2.75; 95% CI 1.71–4.42) and, to a lesser extent, electric clocks (four studies, pooled OR=1.27; 95% CI 1.01–1.60). Our results suggest that ELF-MF higher than 0.4 µT can increase the risk of developing leukemia in children, probably acute lymphoblastic leukemia. Prolonged exposure to electric appliances that generate magnetic fields higher than 0.4 µT like electric blankets is associated with a greater risk of childhood leukemia.

Excerpts

Our results have practical implications. Our meta-analysis suggests that exposure to residential magnetic fields higher than 0.4 µT can increase the risk of leukemia in children. Nevertheless, it is important to emphasize the fact that very few homes are exposed to magnetic fields higher than 0.4 µT generated by overhead power lines in high income countries [11, 30]. Moreover, the annual incidence of childhood leukemia is very low and ranges between 35 and 50 cases per million children in western European countries and North America [69]. Since the absolute risk of childhood leukemia is very low and children are rarely continuously exposed to magnetic fields higher than 0.4 µT in high income countries, the increased leukemia risk found in our meta-analysis does not represent a major public health concern in these countries. Magnetic flux densities higher than 0.4 µT are usually within 50 m of overhead power lines [11] even if Crespi et al. [30] found some subjects living between 50 and 200 m away from overhead power lines (over 200 kV) that were exposed to ELF-MF higher than 0.4 µT. Magnetic flux density measurements should be performed if children live within 200 m of overhead power lines to guarantee that they are not exposed to ELF-MF higher than 0.4 µT. In contrast, living more than 200 m away from overhead power lines could be considered a safe distance for children that is not linked to a higher leukemia risk. Our systematic review suggests that children from middle income countries like Mexico and Iran are more likely to be exposed to magnetic fields above 0.4 µT and the risk of leukemia attributable to ELF-MF is probably higher in these countries. It is noteworthy that none of the studies included in our review have been performed in low income countries or in Africa. More research on ELF-MF and childhood leukemia is needed in these countries, particularly in African countries.

Our meta-analyses suggest that exposure to electric appliances like electric blankets and bedside electric clocks increase the risk of leukemia in children. However, it is important to note that the studies that have found an association between these electric appliances and childhood leukemia have been performed more than 20 years ago and our findings should be interpreted based on the electric equipment used today. Electric blankets and bedside electric clocks used at the end of the twentieth century could generate magnetic fields higher than 0.4 µT and children were typically exposed to these electric appliances during several hours in a row [67]. In contrast, hair dryers can also generate magnetic fields higher than 0.4 µT but are usually used during a shorter period of time [67] and we did not find a significant association between the use of hair dryers and childhood leukemia. These findings are relevant today in the sense that the duration of exposure to ELF-MF plays a role and that children should not be exposed to electric appliances that generate magnetic fields higher than 0.4 µT during long periods of time. Importantly, Magne and colleagues [70] have measured personal exposure to ELF-MF in French children between 2007 and 2009. They have found that alarm clocks were the main variable linked to the magnetic field exposure of the children. The proportion of children exposed to magnetic fields higher than 0.4 μT was 3.1% when all children were included in the analysis and 0.8% when the analysis was restricted to children for which no alarm clock had been identified. Taken together, these results and ours suggest that “bedside” electric clocks and alarm clocks that generate magnetic fields higher than 0.4 μT at close distance should be located at least 1 m away from the bed of the child, because the magnetic flux density generated by electric clocks was lower than 0.4 μT at this distance in the study by Preece et al. [71]. To the best of our knowledge, there is no recent update of the study by Behrens et al. [67] that has performed reliable magnetic flux density measurements for electric appliances manufactured recently that generate ELF-MF. Studies with reliable exposure characterization with respect to sources of ELF-MF are needed, especially for the electric appliances manufactured recently that we use on a daily basis.

In summary, our study suggests that exposure to ELF-MF higher than 0.4 µT increases the risk of developing leukemia in children. Acute lymphoblastic leukemia is probably the subtype of leukemia associated with ELF-MF. Prolonged exposure to electric appliances that generate magnetic fields higher than 0.4 µT like electric blankets is associated with a more elevated risk of childhood leukemia. The distance from power lines linked to leukemia is difficult to determine but living more than 200 m away from power lines is likely a safe distance for children not associated with a higher leukemia risk.

Corresponding author: Christian Brabant, WHO Collaborating Centre for Public Health Aspects of Musculo-Skeletal Health and Ageing, Division of Public Health, Epidemiology and Health Economics, University of Liège, Avenue Hippocrate, 13/B-23, B-4000 Liège, Belgium; and Department of Psychology, Cognition and Behavior, University of Liège, Place des Orateurs, 2/B-32, Liège, Belgium, Phone: +32 43 66 25 81, Fax: +32 43 66 28 12, E-mail:

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Pooled analysis of recent studies of magnetic fields and childhood leukemia

Aryana T. Amoon, John Swanson, Corrado Magnani, Christoffer Johansen, Leeka Kheifets. Pooled analysis of recent studies of magnetic fields and childhood leukemia. Environmental Research. Volume 204, Part A, 2022. doi: 10.1016/j.envres.2021.111993.

Abstract

Background

Over forty epidemiologic studies have addressed an association between measured or calculated extremely-low-frequency magnetic fields (MF) and childhood leukemia. These studies have been aggregated in a series of pooled analyses, but it has been 10 years since the last such.

Methods

We present a pooled analysis combining individual-level data (24,994 cases, 30,769 controls) from four recent studies on MF and childhood leukemia.

Results

Unlike previous pooled analyses, we found no increased risk of leukemia among children exposed to greater MF: odds ratio (OR) = 1.01, for exposure ≥0.4 μT (μT) compared with exposures <0.1 μT. Similarly, no association was observed in the subset of acute lymphoblastic leukemia, birth homes, studies using calculated fields, or when geocoding accuracy was ignored. In these studies, there is a decline in risk over time, also evident when we compare three pooled analyses. A meta-analysis of the three pooled analyses overall presents an OR of 1.45 (95% CI: 0.95–2.20) for exposures ≥0.4 μT.

Conclusions

Our results are not in line with previous pooled analysis and show a decrease in effect to no association between MF and childhood leukemia. This could be due to methodological issues, random chance, or a true finding of disappearing effect.

Funding information 

This work was supported by the research grant from Electric Power Research Institute. SETIL was financially supported by research grants received from the Italian Association on Research on Cancer (AIRC), the Ministry for Instruction, University, and Research, the Ministry of Health, the Ministry of Labour, and Piedmont Region.


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Residential mobility and childhood leukemia

Amoon AT, Oksuzyan S, Crespi CM, Arah OA, Cockburn M, Vergara X, Kheifets L. Residential mobility and childhood leukemia. Environ Res. 2018 Mar 22;164:459-466. doi: 10.1016/j.envres.2018.03.016.

Highlights

• Children who moved were older, had younger mothers, and lower SES.
• Non-movers showed stronger associations with EMF exposures and childhood leukemia.
• Adjustment for variables predicting mobility, save dwelling, did not alter results.
• Mobility does not appear to explain observed links between EMF and leukemia. 

Abstract

AIMS: Studies of environmental exposures and childhood leukemia studies do not usually account for residential mobility. Yet, in addition to being a potential risk factor, mobility can induce selection bias, confounding, or measurement error in such studies. Using data collected for California Powerline Study (CAPS), we attempt to disentangle the effect of mobility.

METHODS: We analyzed data from a population-based case-control study of childhood leukemia using cases who were born in California and diagnosed between 1988 and 2008 and birth certificate controls. We used stratified logistic regression, case-only analysis, and propensity-score adjustments to assess predictors of residential mobility between birth and diagnosis, and account for potential confounding due to residential mobility.

RESULTS: Children who moved tended to be older, lived in housing other than single-family homes, had younger mothers and fewer siblings, and were of lower socioeconomic status. Odds ratios for leukemia among non-movers living <50 meters (m) from a 200+ kilovolt line (OR: 1.62; 95% CI: 0.72-3.65) and for calculated fields ≥ 0.4 microTesla (OR: 1.71; 95% CI: 0.65-4.52) were slightly higher than previously reported overall results. Adjustments for propensity scores based on all variables predictive of mobility, including dwelling type, increased odds ratios for leukemia to 2.61 (95% CI: 1.76-3.86) for living < 50 m from a 200 + kilovolt line and to 1.98 (1.11-3.52) for calculated fields. Individual or propensity-score adjustments for all variables, except dwelling type, did not materially change the estimates of power line exposures on childhood leukemia.

CONCLUSION: The residential mobility of childhood leukemia cases varied by several sociodemographic characteristics, but not by the distance to the nearest power line or calculated magnetic fields. Mobility appears to be an unlikely explanation for the associations observed between power lines exposure and childhood leukemia.

Funding: This work was supported by the Electric Power Research Institute. Crespi was also partially supported by the National Cancer Institute at the National Institutes of Health (grant P30 CA16042). Vergara is an employee of the Electric Power Research Institute.


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Occupational ELF-MF exposure and hematolymphopoietic cancers - 
Swiss National Cohort analysis and updated meta-analysis

Huss A, Spoerri A, Egger M, Kromhout H, Vermeulen R; Swiss National Cohort. Occupational extremely low frequency magnetic fields (ELF-MF) exposure and hematolymphopoietic cancers - Swiss National Cohort analysis and updated meta-analysis. Environ Res. 2018 Mar 24;164:467-474. doi: 10.1016/j.envres.2018.03.022.

Highlights

• ELF-MF exposure may affect specific hematolymphopoietic malignancies rather than “all leukaemia”.
• We evaluated effects of occupational ELF-MF exposure on different types of hematolymphopoietic malignancies.
• We observed increased risks of AML if workers were exposed to higher levels and for a longer period of time.
• Risks were in line with meta-analysed findings of previous studies. 

Abstract

PURPOSE: Previous studies have examined risks of leukaemia and selected lymphoid malignancies in workers exposed to extremely low frequency magnetic fields (ELF-MF). Most studies evaluated hematolymphopoietic malignancies as a combined category, but some analyses suggested that effects may be contained to some specific leukaemia or lymphoma subtypes, with inconsistent results.

METHODS: We examined exposure to ELF-MF and mortality 1990-2008 from different types of hematolymphopoietic cancers in the Swiss National Cohort, using a job exposure matrix for occupations recorded at censuses 1990 and 2000. We analysed 3.1 million workers exposed at different levels to ELF-MF: ever-high, only-medium, only-low exposure using Cox proportional hazard models. We evaluated risk of death from acute myeloid leukaemia (AML), chronic myeloid leukaemia, lymphoid leukaemia, diffuse large B-cell lymphomas, follicular lymphoma, Waldenström's macroglobulinemia, multiple myeloma and Hodgkin lymphoma.

RESULTS: Mortality from hematolymphopoietic cancers was not associated with exposure to ELF-MF with the exception of an increase in ever-high exposed men of myeloid leukaemias (HR 1.31, 95% CI 1.02-1.67), and AML (HR 1.26, 95%CI 0.93-1.70). If workers had been high exposed during their vocational training and at both censuses, these HR increased to 2.24 (95%CI 0.91-5.53) and 2.75 (95%CI 1.11-6.83), respectively.

CONCLUSIONS: Our analysis provided no convincing evidence for an increased risk of death from a range of hematolymphopoietic cancers in workers exposed to high or medium levels of ELF magnetic fields. However, we observed an increased risk of acute myeloid leukaemia in workers exposed to high levels for a longer duration. Observed risks are in line with meta-analysed previous reports on ELF-MF exposure and AML risk, with a summary relative risk of 1.21 (95%CI 1.08-1.37).


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Meta-analysis of extremely low frequency electromagnetic fields and cancer risk: 
a pooled analysis of epidemiologic studies

 Zhang Y, Lai J, Ruan G, Chen C, Wang DW. Meta-analysis of extremely low frequency electromagnetic fields and cancer risk: a pooled analysis of epidemiologic studies. Environ Int. 2015 Dec 15;88:36-43. doi: 10.1016/j.envint.2015.12.012.

 Highlights

• A significant association between ELF-EMF exposure and cancer risk was identified.
• Subgroup analysis revealed increased risk only in North America, especially in United States.
• However, the data from individual European country was contradicted with each other.
• Increased risk was only observed in residential exposure or interview-based surveys.
• Device measured studies obtained no significant association in overall effects.

Abstract

 Human-made electromagnetic fields (EMFs), such as nonionizing radiation, are classified into three categories: extremely low frequency fields (< 300 Hz) ....

Studies have suggested that extremely low frequency electromagnetic fields (ELF-EMF) may affect physiological functions in animal models. However, epidemiologic studies investigating the association of ELF-EMF with the susceptibility to cancer yield contradictory results.

In this comprehensive analysis, we conducted a search for case-control surveys regarding the associations of ELF-EMF and cancer susceptibility in electronic databases. A total of 42 studies involving 13,259 cases and 100,882 controls were retrieved. 

 All studies were case–control studies, including 23 breast cancer ..., 1 testicular cancer ..., 1 acoustic neuroma ..., 1 endometrial cancer ...., and 3 other cancer cases.

Overall, increased susceptibility to cancer was identified in the ELF-EMF exposed population (OR=1.08, 95% CI: 1.01, 1.15, P=0.02). In the stratified analyses, increased risk was found in North America (OR=1.10; 95% CI: 1.02, 1.20, P=0.02), especially the United States (OR=1.10; 95% CI: 1.01, 1.20, P=0.03). However, studies from Europe contradict these results. Moreover, a higher risk was found to be statistically significantly associated with the residential exposed population (OR=1.18; 95% CI: 1.02, 1.37, P=0.03). Furthermore, an increased cancer risk was found in interview-based surveys (OR=1.16; 95% CI: 1.00, 1.35, P=0.04). In device measurement-based studies, a slight increased risk was found only in premenopausal breast cancer (OR=1.23; 95% CI: 1.01, 1.49, P=0.04).

Our meta-analysis suggests that ELF-EMFs are associated with cancer risk, mainly in the United States and in residential exposed populations. Methodological challenges might explain the differences among studies.

http://1.usa.gov/1R4n2AJ


Excerpts

 The overall evaluation conducted by the World Health Organization (WHO) indicated that extremely low-frequency magnetic fields (ELF-EMFs) are possibly carcinogenic to humans (Group 2B), while static electric and magnetic fields and extremely low-frequency electric fields are not classifiable as to their carcinogenicity to humans (Group 3) (Humans, 2002).

ELF-EMFs are mainly generated by power transmission lines, power equipment or appliances (Chen et al., 2013). Because of the rapid development of industry and society, humans are surrounded by various electric devices, and exposure to ELF-EMFs is increasing. Currently, the biological effects induced by ELF-EMFs on human health have become a cause for concern (Grellier et al., 2014 and Zhang et al., 2015).

In general, animal experiments have produced positive results for all known human carcinogens, for which adequate testing has been performed (Humans, 2002). However, it is notable that childhood leukemia is the only cancer outcome for which this association has been consistently found using epidemiological methods (Grellier et al., 2014). It has been hypothesized that experiments designed following the classical two-step initiator–promoter concept of carcinogenesis may not be appropriate for understanding the biological effects of ELF-EMFs, as disease progression may result from complex interactions of genotoxic and non-genotoxic carcinogens (Juutilainen, 2008).

The results in Fig. 2 show that weak association between EMF-ELF exposure and susceptibility to cancer was identified when all the eligible studies were pooled (OR = 1.08, 95% CI: 1.01, 1.15, P = 0.02) regardless of the exposure models or cancer types (Fig. 2).

In the country subgroup analysis, a statistically significant increase in risk was found in North America (15 breast cancer, 3 brain cancer, 1 leukemia and 1 other cancer; OR = 1.10, 95% CI: 1.02, 1.20, P = 0.02), mainly in the United States (14 breast cancer, 3 brain cancer and 1 other cancer; OR = 1.10, 95% CI: 1.01, 1.20, P = 0.03). On the contrary, no statistically significant association between EMF-ELFs and cancer risk was found in a global analysis of European studies (7 breast cancer, 7 brain cancer, 8 leukemia and 5 other cancers) .... An increased risk of cancer was found in Norway (3 breast cancer, 1 brain cancer, 1 leukemia and 1 other cancer; OR = 1.11, 95% CI: 1.02, 1.21, P = 0.02) and France (1 brain cancer and 1 leukemia; OR = 1.38, 95% CI: 1.03, 1.84, P = 0.03), while a decreased risk was found in Sweden (4 breast cancer, 1 brain cancer, 1 leukemia and 1 other cancer; OR = 0.90, 95% CI: 0.84, 0.96, P = 0.001) and England (2 brain cancer, 2 leukemia and 2 other cancers; OR = 0.82, 95% CI: 0.69, 0.96, P = 0.02). In addition, a study from New Zealand also showed an increased cancer risk (1 leukemia; OR = 1.97, 95% CI: 1.08, 3.59, P = 0.03) .... Further subgroup analyses based on cancer type did not reveal any statistically significant associations in all of the analyzed types. When compared by exposure methods, an increased risk was only observed in residential exposure populations (OR = 1.18; 95% CI: 1.02, 1.37, P = 0.03).  

 [Note that the 23 studies that examined breast cancer risk yielded a marginally significant association with ELF-EMF exposure (OR = 1.07, p = .06)].

In conclusion, in our study, relevant literature selected from broad databases with stringent standards revealed an increased risk of cancer upon ELF-EMF exposure. However, more quantitative studies will contribute to more comprehensive results in the future.

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Sunday, March 13, 2022

Does exposure to 4G LTE cell phone radiation impair cell phone users' health?

Although 4G has been in use for over a decade and far more people in the world are currently exposed to 4G mobile phone radiation than 5G, little attention has been paid to the potential harmful health effects of this environmental pollutant.

4G, also known as Long Term Evolution or LTE, is the fourth generation of cellular technology. It employs new digital signal processing and modulation to increase the capacity and speed of wireless telecommunications networks. 

The standard for LTE was finalized in December, 2008, and the first mobile phone to employ this technology was released in September 2010. By the end of 2017, 41 countries supported LTE coverage over at least 75% of their land area. In North America, the number of LTE mobile devices in use, 365 million, exceeded the size of the population. By 2021, 70 countries had LTE coverage available to at least 75% of the population.

Like 5G, LTE was launched without any pre-market safety testing. Research has found that exposure to LTE radiation leads to a change in intracellular reactive oxygen species (ROS) that may result in "genotoxic stress, decreased proliferation and cell senescence, or no physiological effects depending on ROS concentration and the differential sensitivity of various cells to ROS." Several studies on human subjects have found that short-term exposure to LTE radiation affects brain functioning. No research has examined the health effects of long-term exposure to LTE.

Although 4G technology has been in use for more than a decade, few studies have been conducted on the effects of exposure. The abstracts for these studies appear below.

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Exposure to 1800 MHz LTE electromagnetic fields under proinflammatory conditions decreases the response strength and increases the acoustic threshold of auditory cortical neurons

Samira Souffi, Julie Lameth, Quentin Gaucher, Délia Arnaud-Cormos, Philippe Lévêque, Jean-Marc Edeline, Michel Mallat. Exposure to 1800 MHz LTE electromagnetic fields under proinflammatory conditions decreases the response strength and increases the acoustic threshold of auditory cortical neurons. Sci Rep. 2022 Mar 8;12(1):4063. doi: 10.1038/s41598-022-07923-9.

Abstract

Increased needs for mobile phone communications have raised successive generations (G) of wireless technologies, which could differentially affect biological systems. To test this, we exposed rats to single head-only exposure of a 4G long-term evolution (LTE)-1800 MHz electromagnetic field (EMF) for 2 h. We then assessed the impact on microglial space coverage and electrophysiological neuronal activity in the primary auditory cortex (ACx), under acute neuroinflammation induced by lipopolysaccharide. The mean specific absorption rate in the ACx was 0.5 W/kg. Multiunit recording revealed that LTE-EMF triggered reduction in the response strength to pure tones and to natural vocalizations, together with an increase in acoustic threshold in the low and medium frequencies. Iba1 immunohistochemistry showed no change in the area covered by microglia cell bodies and processes. In healthy rats, the same LTE-exposure induced no change in response strength and acoustic threshold. Our data indicate that acute neuroinflammation sensitizes neuronal responses to LTE-EMF, which leads to an altered processing of acoustic stimuli in the ACx.

Excerpt

In conclusion, our study reveals that a single head-only exposure to LTE-1800 MHz can interfere with the neuronal responses of cortical neurons to sensory stimuli. In line with previous characterizations of the effect of GSM-signal, our results show that the impact of LTE signal on neuronal activity varies according to the health state. Acute neuroinflammation sensitize neuronal responses to LTE-1800 MHz, resulting in altered cortical processing of auditory stimuli.


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The effect of 4.5 G (LTE Advanced-Pro network) mobile phone radiation 
on the optic nerve

Erkin Özdemir, Ülkü Çömelekoglu, Evren Degirmenci, Gülsen Bayrak, Metin Yildirim, Tolgay Ergenoglu, Banu Coşkun Yılmaz, Begüm Korunur Engiz, Serap Yalin, Dilan Deniz Koyuncu, Erkan Ozbay. The effect of 4.5 G (LTE Advanced-Pro network) mobile phone radiation on the optic nerve. Cutan Ocul Toxicol. 2021 Mar 3;1-27. doi: 10.1080/15569527.2021.1895825.

Abstract

Purpose: Rapid development in mobile phone technologies increase the average mobile phone usage duration. This increase also triggers exposure to radiofrequency radiation (RF), which is a risk factor for the health. In this study, it was aimed to investigate the effect of mobile phone working with LTE-Advanced Pro (4.5G) mobile network on the optic nerve, which is responsible for the transmission of visual information.

Material and methods: Thirty-two rats divided into two groups as control (no RF, sham exposure) and experimental (RF exposure using a mobile phone with LTE-Advanced Pro network; 2 hours/day, 6 weeks). The visual evoked potential (VEP) was recorded and determined amplitudes and latencies of VEP waves. Optic nerve malondialdehyde level, catalase and superoxide dismutase activities were determined. Furthermore, ultrastructural and morphometric changes of optic nerve were evaluated.

Results: In VEP recordings, the mean VEP amplitudes of experimental group were significantly lower than control group. In ultrastructural evaluation, myelinated nerve fibers and glial cells were observed in normal histologic appearance both in sham and experimental group. However, by performing morphometric analysis, in the experimental group, axonal diameter and myelin thickness were shown to be lower and the G-ratio was higher than in the sham group. In the experimental group, malondialdehyde level was significantly higher and superoxide dismutase and catalase activities were significantly lower than sham group. There was a high correlation between VEP wave amplitudes and oxidative stress markers.

Conclusion: Findings obtained in this study support optic nerve damage. These results point out an important risk that may decrease the quality of life.


Excerpts

In recent years, everyone, from child to old, has a smartphone, and everyday a long time is passed looking at the screen of this phone. Comfort and efficiency achieved thanks to the high data transfer rate provided by LTE-Advanced Pro technology increase this time day by day. Eyes are the most affected body parts from this condition. In addition to the effects such as strabismus and eye impairment arising from looking at a small screen, it is also important to examine the hidden risks that the RF magnetic field created by the phone will cause on the eye. In this study, the effects of RF emission created by a LTE-Advanced Pro technology phone on the optic nerve were examined in all aspects and the findings were given in the previous section. Briefly it can be said that, for the first time in scientific literature, the findings of the present study indicate that the LTE-Advanced Pro mobile phone radiation causes significant damage by triggering oxidative stress in the optic nerve. LTE-Advanced Pro technology uses a wider RF band between 800 MHz and 2600 MHz and the network system selects the most appropriate band itself according to the user’s requirements. It is known that penetration depth of RF increases with decreasing frequency [39]. Since effects of RF radiation were observed on the optic nerve which is behind the eye, it can be said that low frequency bands such as 800 MHz were mostly active during the experiments. Maybe this inference cannot be generalized for all communication purposes, but usage probability of low frequency bands during LTE-Advanced Pro smart phone usage will always keep the damage risk on optic nerve alive.

Fig. 3A and 3B show the distribution of electric field and SAR, respectively. As seen, maximum E field was 5.0 V/m (Fig. 3A) and maximum SAR (10 g) was 0.01 W/kg (Fig. 3B). The SAR value in the area of eyes was about 0.0035 W/kg (Fig. 3B).

Before and after exposure, body surface temperatures were 28.08 ± 0.19 and 28.07 ± 0.26 °C, respectively in the sham group. These values were 28.37 ± 0.29 and 28.39 ± 0.22 °C, respectively for the RF groups. There was no significant difference within sham (p = 0.275) and RF (p = 0.120) groups before and after exposure. Also, there was no significant differences in surface body temperature between sham and RF exposed groups before (p = 0.142) and after (p = 0.321) exposure.

In the present study, for the first time, it was shown that exposition to 4.5 G mobile phone radiation for 2 hours/day for 6 weeks causes optic nerve damage. The optic nerve transmits all visual information to the visual cortex, and any damage in this nerve can cause permanent and serious vision loss. This study demonstrated that RF exposure may be an environmental risk factor for eye toxicity and potential eye disorders. Further studies are needed to reveal the potentiality of the risk in this area.  

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Hematobiochemical and histopathological alterations of kidney and testis 
due to exposure of 4G cell phone radiation in mice

Imam Hasan, Tanjina Amin, Md. Rafiqul Alam, Mohammad Rafiqul Islam. Hematobiochemical and histopathological alterations of kidney and testis due to exposure of 4G cell phone radiation in mice. Saudi Journal of Biological Sciences. Available online 17 February 2021. https://doi.org/10.1016/j.sjbs.2021.02.028.

Abstract

The radiofrequency electromagnetic radiation emitted by smart phones on biological systems has wide media coverage and public concern in recent years. The aim of this study was to explore the effects of fourth-generation cell phone radiation exposure on hematological (Total leukocyte count, Total erythrocyte count, and hemoglobin %), biochemical (Serum creatinine) parameters, and histopathological changes in the kidney and testis of Swiss albino mice. A total of 30 male Swiss albino mice weighing 45–65 g was randomly divided into three groups (n = 10). The first group A was the control group, the second group B, was exposed to 40 minutes of mobile phone radiation daily, the third group C was exposed to 60 minutes of radiation daily from two 2400 Megahertz fourth-generation connected mobile phones for 60 days, respectively. The electromagnetic radiation frequency radiometer measured the frequency of electromagnetic radiation emitted from cell phones. The specific absorption rate was calculated as 0.087 W/kg. The control group was kept under similar conditions, but the electromagnetic field was not given for the same period. All the mice were sacrificed at the end of the experiment. The blood samples were collected for hematobiochemical study, and then kidney and testis tissues were collected for histopathological study. Results of the study showed that the body weight and total erythrocyte count values were significantly (p < 0.05) decreased while total leukocyte count, hemoglobin %, and serum creatinine values were significantly (p < 0.05) increased in both the radiation exposure groups relative to the control group. Histopathological observation showed the kidney of 60 minutes exposed mice interstitial inflammation that causes marked mononuclear cellular infiltration compared to the 40 minutes and control mice. Compared to control mice, histopathological examinations of testicular tissue from the exposed mice, showed irregular in shapes and non-uniform sizes and fewer spermatogenic cells layer that leads to the larger lumen in the seminiferous tubules. It is concluded that fourth-generation cell phone radiation exposure may affect blood hemostasis and inflammation of mice's kidney and testis tissue. Based on these studies, it is important to increase public consciousness of potential adverse effects of mobile phone radiofrequency electromagnetic radiation exposure.


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Empirical study on specific absorption rate of head tissues due to induced heating of 4G cell phone radiation

Christopher B, Mary S, Khandaker MU, Jojo PJ. Empirical study on specific absorption rate of head tissues due to induced heating of 4G cell phone radiation. Radiation Physics and Chemistry. 178(Special Issue): 108910. Jan 2021. DOI:10.1016/j.radphyschem.2020.108910.

Abstract

Exposures to electromagnetic radiation mainly from the extended use of mobile phones may initiate biological damages in the human body at the macromolecular level. Several studies on human and animal models have shown significant changes in the functions of neural cells. Present empirical study analyses the thermal changes and the specific absorption rates (SAR) of brain, eye and skin tissues due to prolonged exposure to mobile phone radiation. A phantom, simulating human head with skin, skull and brain was used for the study. The Phantom was exposed to radiation for longer durations (600 s and more) and the temperature variations at different specific points were studied with sensitive thermocouple probes. SAR (1 g of contiguous tissue) values were determined using the variations of temperature and other parameters. The average rise in brain temperature was found to be 0.10 +/- 0.05 degrees C at 30 mm deep in the brain and the estimated SAR was 0.66 +/- 0.35 Wkg(-1). The increase in temperature for the eye socket was 0.03 +/- 0.02 degrees C with SAR 0.15 +/- 0.08 Wkg(-1). The average rise in temperature for skin was 0.14 +/- 0.05 degrees C and the SAR was 0.66 +/- 0.42 Wkg(-1). Although the measured SAR lie within the safe limit of 2 Wkg(-1) recommended by the international regulatory body, considering the tremendous growth in the number of mobile phone users and prolonged use of mobile phone in communication purposes, the cumulative effects could be a real concern for human health.


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Functional and network analyses of human exposure to long-term evolution signal

Lei Yang, Chen Zhang, Zhiye Chen, Congsheng Li, Tongning Wu. Functional and network analyses of human exposure to long-term evolution signal. Environ Sci Pollut Res Int. 2020 Sep 25. doi: 10.1007/s11356-020-10728-w.

Abstract

Human exposure to the electromagnetic field emitted by wireless communication systems has raised public concerns. There were claims of the potential association of some neurophysiological disorders with the exposure, but the mechanism is yet to be established. The wireless networks, recently, experience a transition from the 4th generation (4G) to 5th generation (5G), while 4G long-term evolution (LTE) is still the frequently used signal in wireless communication. In the study, exposure experiments were conducted using the LTE signal. The subjects were divided into sham and real exposure groups. Before and after the exposure experiments, they underwent functional magnetic resonance imaging. Within-session and between-session comparisons have been executed for functional connectivity and network properties. Individual specific absorption rate (SAR) was also calculated. The results indicated that acute LTE exposure beneath the safety limits modulated both the functional connection and graph-based properties. To characterize the effect of functional activity, SAR averaged over a certain tissue mass was not an appropriate metric. The potential neurophysiological effect of 5G exposure has also been discussed in the study.

https://pubmed.ncbi.nlm.nih.gov/32974829/

Excerpts

Since 2019, the fifth-generation (5G) wireless network has been implemented. Two different frequency ranges available for 5G wireless technology include- frequency range 1 (FR1) and frequency range 2 (FR2). At present, the popular commercial frequency at FR1 was around 2.4 and 3.5 GHz, close to the current 3G and 4G frequencies. The emission power of 5G mobile phones is comparable to that of 3G and 4G terminals. Most of the existed literature, as well as our studies, narrated similar activated sites (frontal and temporal lobules) for different frequencies/modulations. It is, therefore, reasonable to expect that the exposure to new generation wireless signals would result in a similar effect.

Conclusion

Human brain modulation following LTE exposure was first evaluated by functional and network metrics. The topological changes have been reported, and their consistency with the previous analysis was highlighted. Integrating the results from the regional BOLD variation, intraregional similarity, and hypothesis-driven FC analysis, a comprehensive view for the brain activity by the exposure of LTE signal and the signal of next-generation can be obtained. Another novelty was that no correlation was found between the peak SAR values and the altered topological parameters. It demonstrated peak SAR averaged over a certain mass, which was used for assessing the thermal effect of human exposure, was incongruous to quantify the neurophysiological effect of EMF exposure. It may clarify the inconsistency in current human exposure studies.

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Continuous Exposure to 1.7 GHz LTE (4G) Electromagnetic Fields Increases Intracellular Reactive Oxygen Species to Decrease Human Cell Proliferation and Induce Senescence

Jisu Choi, Kyeongrae Min, Sangbong Jeon, Nam Kim, Jeong-Ki Pack, Kiwon Song. Continuous Exposure to 1.7 GHz LTE Electromagnetic Fields Increases Intracellular Reactive Oxygen Species to Decrease Human Cell Proliferation and Induce Senescence. Sci Rep. 2020 Jun 8;10(1):9238. doi: 10.1038/s41598-020-65732-4.

Abstract

Due to the rapid development of mobile phone technology, we are continuously exposed to 1.7 GHz LTE radio frequency electromagnetic fields (RF-EMFs), but their biological effects have not been clarified. Here, we investigated the non-thermal cellular effects of these RF-EMFs on human cells, including human adipose tissue-derived stem cells (ASCs), Huh7 and Hep3B liver cancer stem cells (CSCs), HeLa and SH-SY5Y cancer cells, and normal fibroblast IMR-90 cells. When continuously exposed to 1.7 GHz LTE RF-EMF for 72 h at 1 and 2 SAR, cell proliferation was consistently decreased in all the human cells. The anti-proliferative effect was higher at 2 SAR than 1 SAR and was less severe in ASCs. The exposure to RF-EMF for 72 h at 1 and 2 SAR did not induce DNA double strand breaks or apoptotic cell death, but did trigger a slight delay in the G1 to S cell cycle transition. Cell senescence was also clearly observed in ASC and Huh7 cells exposed to RF-EMF at 2 SAR for 72 h. Intracellular ROS increased in these cells and the treatment with an ROS (reactive oxygen species) scavenger recapitulated the anti-proliferative effect of RF-EMF. These observations strongly suggest that 1.7 GHz LTE RF-EMF decrease proliferation and increase senescence by increasing intracellular ROS in human cells.

Conclusion

Altogether, this study as well as other studies strongly suggest that RF-EMF exposure leads to a change in intracellular ROS levels that may result in genotoxic stress, decreased proliferation and cell senescence, or no physiological effects depending on ROS concentration and the differential sensitivity of various cells to ROS. Thus, the mechanism behind RF-EMF exposure altering intracellular ROS levels should be further studied to elucidate the biological effects of RF-EMFs.

 It is not plausible to directly predict the physiological effects of 1.7 GHz LTE RF-EMF from our cell-based study. However, the anti-proliferative effect of 1.7 GHz LTE RF-EMF on various human cells in this study suggests that the exposure to 1.7 GHz LTE RF-EMF would be more harmful to children, whose adult stem cells should be very active for growth and may accelerate the aging of body cells. We also carefully suggest that the anti-proliferative effect of various cancer cells by 1.7 GHz LTE RF-EMF would be interpreted with care, considering that both positive and negative effects of RF-EMF have been reported on cancer development.

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Empirical study on specific absorption rate of head tissues due to induced heating of 4G cell phone radiation

Christopher B, Mary YS, Khandaker MU, Jojo PJ. Empirical study on specific absorption rate of head tissues due to induced heating of 4G cell phone radiation. Radiation Physics and Chemistry. Published online Apr 4, 2020. https://doi.org/10.1016/j.radphyschem.2020.108910

Highlights

• Induced heating of 4G cell phone radiation affects the functions of neural cells.
• Temperature and SAR of brain, eye and skin tissues are measured in laboratory condition.
• Rise in temperature and SAR values are found in the studied tissues for confrontation of 600 s.
• Long time and over exposure to mobile phone radiation may affect the individual health.

Abstract

Exposures to electromagnetic radiation mainly from the extended use of mobile phones may initiate biological damages in the human body at the macromolecular level. Several studies on human and animal models have shown significant changes in the functions of neural cells. Present empirical study analyses the thermal changes and the specific absorption rates (SAR) of brain, eye and skin tissues due to prolonged exposure to mobile phone radiation. A phantom, simulating human head with skin, skull and brain was used for the study. The Phantom was exposed to radiation for longer durations (600 s and more) and the temperature variations at different specific points were studied with sensitive thermocouple probes. SAR (1 g of contiguous tissue) values were determined using the variations of temperature and other parameters. The average rise in brain temperature was found to be 0.10 ± 0.05 °C at 30 mm deep in the brain and the estimated SAR was 0.66 ± 0.35 Wkg-1. The increase in temperature for the eye socket was 0.03 ± 0.02 °C with SAR 0.15 ± 0.08 Wkg-1. The average rise in temperature for skin was 0.14 ± 0.05 °C and the SAR was 0.66 ± 0.42 Wkg-1. Although the measured SAR lie within the safe limit of 2 Wkg-1 recommended by the international regulatory body, considering the tremendous growth in the number of mobile phone users and prolonged use of mobile phone in communication purposes, the cumulative effects could be a real concern for human health.


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 Effects of mobile phone radiation on certain hematological parameters

 Christopher B, Sheena MY, Uddin Khandaker M, Bradley DA, Chew MT, Jojo PJ.  Effects of mobile phone radiation on certain hematological parameters. Radiation Physics and Chemistry. Published online September 14, 2019. 108443. https://doi.org/10.1016/j.radphyschem.2019.108443.

 Highlights

 • Mobile phone radiation affects blood hemoglobin level, white blood cell and platelets count and erythrocytes sedimentation rate.
• Effects of mobile phone radiation on hematological factors studied in a controlled condition in the laboratory.
• A matched case control approach was adopted for the investigation.
• Long time and over exposure to mobile phone radiation may affect the individual health.

 Abstract

 Exorbitant chronic exposure to any sort of radiation is hazardous to human health. Besides ionizing radiation, exposures to electromagnetic radiation mainly from the use of mobile phones have become a matter of great health concern, especially its extortionate use even by children. At the same time there are several myths related to the ill effects including carcinogenicity of the prolonged exposure continuously. The objective of this investigation was to find the effect on certain vital hematological parameters namely hemoglobin level, white blood cell (WBC) count, platelet count and erythrocytes sedimentation rate (ESR) level due to the prolonged exposure to mobile radiations through in vitro examination of human blood samples. Matched case control methodology was adopted for the study. Blood samples were collected by clinicians from 27 voluntary subjects for investigation. From each, one sample was kept un-exposed while the other three samples were exposed to mobile microwave radiations for 60 min continuously in identical and controlled conditions. A 4G hand phone of a very popular brand having transmission frequency range from 2.3 to 2.4 GHz including uplink and downlink was used. Hematological analyses were carried out on fresh samples immediately after collection. For comparison of the levels of hematological parameters, blood exposed to 1 h of phone radiation and control were analysed. Experimental results show that there is a significant change on the hematological components. The exposed blood samples were found to have decrease in platelet count only. Hemoglobin level, ESR rate and the WBC counts were found to be increased. While these observations are performed in a controlled laboratory conditions, the tremendous growth in number of mobile phone users, the effects could be many more folds especially in work places and cities even through passive exposure.

 https://www.sciencedirect.com/science/article/abs/pii/S0969806X19305481

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 Early-life exposure to pulsed LTE radiofrequency fields causes persistent changes in activity and behavior in mice

 Broom KA, Findlay R, Addison DS, Goiceanu C, Sienkiewicz Z. Early-life exposure to pulsed LTE radiofrequency fields causes persistent changes in activity and behavior in C57BL/6 J mice. Bioelectromagnetics. 2019 Sep 15. doi: 10.1002/bem.22217.

Abstract

 Despite much research, gaps remain in knowledge about the potential health effects of exposure to radiofrequency (RF) fields. This study investigated the effects of early-life exposure to pulsed long term evolution (LTE) 1,846 MHz downlink signals on innate mouse behavior. Animals were exposed for 30 min/day, 5 days/week at a whole-body average specific energy absorption rate (SAR) of 0.5 or 1 W/kg from late pregnancy (gestation day 13.5) to weaning (postnatal day 21). A behavioral tracking system measured locomotor, drinking, and feeding behavior in the home cage from 12 to 28 weeks of age. The exposure caused significant effects on both appetitive behaviors and activity of offspring that depended on the SAR. Compared with sham-exposed controls, exposure at 0.5 W/kg significantly decreased drinking frequency (P ≤ 0.000) and significantly decreased distance moved (P ≤ 0.001). In contrast, exposure at 1 W/kg significantly increased drinking frequency (P ≤ 0.001) and significantly increased moving duration (P ≤ 0.005). In the absence of other plausible explanations, it is concluded that repeated exposure to low-level RF fields in early life may have a persistent and long-term effect on adult behavior.

https://www.ncbi.nlm.nih.gov/pubmed/31522469

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 Long-term exposure to 4G smartphone radiation diminished male reproductive potential in testes of adult rats

 Yu G, Tang Z, Chen H, Chen Z, Wang L, et al.  Long-term exposure to 4G smartphone radiofrequency electromagnetic radiation diminished male reproductive potential by directly disrupting Spock3-MMP2-BTB axis in the testes of adult rats. Sci Total Environ. 2019 Aug 31;698:133860. doi: 10.1016/j.scitotenv.2019.133860.

 Abstract

 The correlation between long-term exposure to SRF-EMR and the decline in male fertility is gradually receiving increasing attention from the medical society. While male reproductive organs are often exposed to SRF-EMR, little is currently known about the direct effects of long-term SRF-EMR exposure on the testes and its involvement in the suppression of male reproductive potential. The present study was designed to investigate this issue by using 4G SRF-EMR in rats. A unique exposure model using a 4G smartphone achieved localized exposure to the scrotum of the rats for 6 h each day (the smartphone was kept on active talk mode and received an external call for 1 min over 10 min intervals). Results showed that SRF-EMR exposure for 150 days decreased sperm quality and pup weight, accompanied by testicular injury. However, these adverse effects were not evident in rats exposed to SRF-EMR for 50 days or 100 days. Sequencing analysis and western blotting suggested Spock3 overexpression in the testes of rats exposed to SRF-EMR for 150 days. Inhibition of Spock3 overexpression improved sperm quality decline and alleviated testicular injury and BTB disorder in the exposed rats. Additionally, SRF-EMR exposure suppressed MMP2 activity, while increasing the activity of the MMP14-Spock3 complexes and decreasing MMP14-MMP2 complexes; these results were reversed by Spock3 inhibition. Thus, long-term exposure to 4G SRF-EMR diminished male fertility by directly disrupting the Spock3-MMP2-BTB axis in the testes of adult rats. To our knowledge, this is the first study to show direct toxicity of SRF-EMR on the testes emerging after long-term exposure.

https://www.ncbi.nlm.nih.gov/pubmed/31514029

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 Short-term radiofrequency exposure from new generation mobile phones reduces EEG alpha power with no effects on cognitive performance.

 Vecsei Z, Knakker B, Juhász P, Thuróczy G, Trunk A, Hernádi I. Short-term radiofrequency exposure from new generation mobile phones reduces EEG alpha power with no effects on cognitive performance. Sci Rep. 2018 Dec 20;8(1):18010. doi: 10.1038/s41598-018-36353-9.

 Abstract

 Although mobile phone (MP) use has been steadily increasing in the last decades and similar positive trends are expected for the near future, systematic investigations on neurophysiological and cognitive effects caused by recently developed technological standards for MPs are scarcely available. Here, we investigated the effects of radiofrequency (RF) fields emitted by new-generation mobile technologies, specifically, Universal Mobile Telecommunications System (UMTS) and Long-Term Evolution (LTE), on intrinsic scalp EEG activity in the alpha band (8-12 Hz) and cognitive performance in the Stroop test. The study involved 60 healthy, young-adult university students (34 for UMTS and 26 for LTE) with double-blind administration of Real and Sham exposure in separate sessions. EEG was recorded before, during and after RF exposure, and Stroop performance was assessed before and after EEG recording. Both RF exposure types caused a notable decrease in the alpha power over the whole scalp that persisted even after the cessation of the exposure, whereas no effects were found on any aspects of performance in the Stroop test. The results imply that the brain networks underlying global alpha oscillations might require minor reconfiguration to adapt to the local biophysical changes caused by focal RF exposure mimicking MP use.

 Open access paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6301959/

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 The Effect of a Single 30-Min Long Term Evolution Mobile Phone-Like Exposure on Thermal Pain Threshold of Young Healthy Volunteers

 Vecsei Z, Thuróczy G, Hernádi I. The Effect of a Single 30-Min Long Term Evolution Mobile Phone-Like Exposure on Thermal Pain Threshold of Young Healthy Volunteers. Int J Environ Res Public Health. 2018 Aug 27;15(9). pii: E1849. doi: 10.3390/ijerph15091849.

Abstract

 Although the majority of mobile phone (MP) users do not attribute adverse effects on health or well-being to MP-emitted radiofrequency (RF) electromagnetic fields (EMFs), the exponential increase in the number of RF devices necessitates continuing research aimed at the objective investigation of such concerns. Here we investigated the effects of acute exposure from Long Term Evolution (LTE) MP EMFs on thermal pain threshold in healthy young adults. We use a protocol that was validated in a previous study in a capsaicin-induced hyperalgesia model and was also successfully used to show that exposure from an RF source mimicking a Universal Mobile Telecommunications System (UMTS) MP led to mildly stronger desensitization to repeated noxious thermal stimulation relative to the sham condition. Using the same experimental design, we did not find any effects of LTE exposure on thermal pain threshold. The present results, contrary to previous evidence obtained with the UMTS modulation, are likely to originate from placebo/nocebo effects and are unrelated to the brief acute LTE EMF exposure itself. The fact that this is dissimilar to our previous results on UMTS exposure implies that RF modulations might differentially affect pain perception and points to the necessity of further research on the topic.


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Modulation of brain functional connectivity by exposure to LTE (4G) cell phone radiation 

Wei Y, Yang J, Chen Z, Wu T, Lv B. Modulation of resting‐state brain functional connectivity by exposure to acute fourth‐generation long‐term evolution electromagnetic field: An fMRI study. Bioelectromagnetics. Published online 18 December 2018. 

Abstract

By now, the neurophysiological effect of electromagnetic field (EMF) exposure and its underlying regulating mechanisms are not well manifested. In this study, we aimed to investigate whether acute long‐term evolution (LTE) EMF exposure could modulate brain functional connectivity using regional homogeneity (ReHo) method and seed‐based analysis on resting‐state functional magnetic resonance imaging (fMRI). We performed the LTE‐EMF  exposure experiment and acquired the resting‐state brain activities before and after EMF exposure. Then we applied ReHo index to characterize the localized functional connectivity and seed‐based method to evaluate the inter‐regional functional connectivity. Statistical comparisons were conducted to identify the possible evidence of brain functional connectivity modulation induced by the acute LTE‐EMF exposure. We found that the acute LTE‐EMF exposure modulated localized intra‐regional connectivity (p < 0.05, AlphaSim corrected, voxel size ≥ 18) and inter‐regional connectivity in some brain regions (p < 0.05, AlphaSim corrected, voxel size ≥ 18). Our results may indicate that the approaches relying on network‐level inferences could provide deeper insight into the acute effect on human functional activity induced by LTE‐EMF exposure.

Excerpts

"Currently, multiple standards exist for wireless communication, which ranges from second‐generation (2G, GSM) to third‐generation (3G, UMTS) and fourth‐generation (4G, LTE) networks in daily life. Fifth‐generation (5G) networks will start to appear as a commercial infrastructure in the near future. Although we enjoy the convenience of mobile phones, the widespread use of them has raised attention about the possible health effects of radiofrequency (RF) electromagnetic field (EMF) exposure [ICNIRP, 1998].

With neuroimaging and neuropsychology tools, the effect of EMF on the human brain can be reflected as signals of electrical activity [Hamblin et al., 2006; Croft et al., 2010; Lustenberger et al., 2013; Roggeveen et al., 2015a, b], cortical excitability [Tombini et al., 2013], cerebral blood flow [Aalto et al., 2006], brain glucose metabolism [Volkow et al., 2011], and hemodynamic responses [Volkow et al., 2011; Curcio et al., 2012]. Previous studies reported that GSM signals modulated alpha band power in resting‐state electroencephalogram (EEG) [Croft et al., 2010] or some event‐related potential (ERP) components during cognitive tasks [Hamblin et al., 2006], whereas other studies did not detect any GSM exposure‐induced changes in brain activity [Curcio et al., 2012]. Although some studies showed no significant effects of 3G signals on any neurophysiological measurements [Zhang et al., 2017], recent EEG studies reported significant EEG alterations associated with 3G mobile phone radiation [Roggeveen et al., 2015a, b]. The inconsistency could partly be attributed to different exposure frequencies, modulation modes, and exposure durations [Zhang et al., 2017]. For 4G‐related signals, only our two previous studies have investigated the acute effect of long‐term evolution (LTE) EMF exposure on human brain function [Lv et al., 2014; Yang et al., 2016] using EEG and functional magnetic resonance imaging (fMRI). We found that 30 min of LTE‐EMF exposure modulated the alpha/beta EEG bands [Yang et al., 2016] and spontaneous low‐frequency fluctuations [Lv et al., 2014] in some brain regions. Since LTE networks have been widely deployed, we should make more effort to evaluate the possible effects of LTE‐EMF exposure from different perspectives."

"In this study, we aimed to investigate whether acute LTE‐EMF exposure could modulate brain functional connectivity using resting‐state fMRI. We performed LTE‐EMF exposure experiments lasting for 30 min under a controllable environment and recorded the resting‐state brain activities before and after EMF exposure. Then, we applied the regional homogeneity (ReHo) index [Zang et al., 2004] to characterize localized intraregional connectivity and the seed‐based functional connectivity method [Margulies et al., 2010] to evaluate interregional brain connectivity. Statistical comparisons were conducted to identify possible evidence of brain functional connectivity modulation induced by acute LTE‐EMF exposure."

“To eliminate study biases, we employed a double‐blind, crossover, randomized, and counterbalanced design. Each participant underwent two experimental sessions including real exposure and sham exposure, which were separated by 1 day….The time‐division LTE signal (2.573 GHz) was produced by a signal generator a standard formulation for LTE signals….The power delivered to the standard dipole of 2.6 GHz was 24 dBm (mean value), which was equivalent to a theoretical maximal emission by an LTE terminal. The experiments were conducted in a shielding room to avoid the influence of environmental EMF. Each exposure session lasted for 30 min.”

“Numerical simulations that yielded spatial peak SAR averaging over 10 g tissues for the subjects was 0.98 ± 0.27 W/kg, with a maximal value of 1.52 W/kg, which was below the safety limits [ICNIRP, 1998].”

“In our previous studies, we found that LTE‐EMF exposure depressed the amplitude of spontaneous low frequency fluctuations (ALFFs) in some brain regions [Lv et al., 2014], such as those surrounding the left superior temporal gyrus and middle temporal gyrus (STG_L and MTG_L), right superior temporal gyrus (STG_R), right medial frontal gyrus, and right paracentral lobule (MFG_R and PCL_R). In the present study, we found new evidence that acute LTE‐EMF exposures lasting for 30 min modulated brain functional connectivity including not only localized intraregional connectivity, but also interregional connectivity.”

"Although the SAR values by LTE‐EMF exposure indicated no obvious temperature increase during the exposure experiments and the brain was excellent in terms of thermal regulation, we could not preclude that thermal changes, even minute changes, could be responsible for the instantaneous changes in neural firing. SAR is a metric averaging over 6 min, and its applicability for neurological studies should be discussed."

Conclusion

"Our results may indicate that approaches relying on network‐level inferences can provide deeper insights into the acute effects of LTE‐EMF exposure with intensities below the current safety limits on human functional connectivity. In the future, we need to investigate the evolution of the effect over time.”


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 Effect of Electromagnetic Waves from Mobile Phones on Spermatogenesis in the Era of 4G-LTE

 Oh JJ, Byun SS, Lee SE, Choe G, Hong SK. Effect of Electromagnetic Waves from Mobile Phones on Spermatogenesis in the Era of 4G-LTE. Biomed Res Int. 2018 Jan 29;2018:1801798.

 Abstract

 Objective  To investigate the effect of long duration exposure to electromagnetic field from mobile phones on spermatogenesis in rats using 4G-LTE.

Methods  Twenty Sprague-Dawley male rats were placed into 4 groups according to the intensity and exposure duration: Group 1 (sham procedure), Group 2 (3 cm distance + 6 h exposure daily), Group 3 (10 cm distance + 18 h exposure daily), and Group 4 (3 cm distance + 18 h exposure daily). After 1 month, we compared sperm parameters and histopathological findings of the testis.

Results  The mean spermatid count (×106/ml) was 398.6 in Group 1, 365.40 in Group 2, 354.60 in Group 3, and 298.60 in Group 4 (p = 0.041). In the second review, the mean count of spermatogonia in Group 4 (43.00) was significantly lower than in Group 1 (57.00) and Group 2 (53.40) (p < 0.001 and p = 0.010, resp.). The sum of the germ cell counts was decreased in Group 4 compared to Groups 1, 2, and 3 (p = 0.032). The mean Leydig cell count was significantly decreased in Group 4 (p < 0.001).

Conclusions  The longer exposure duration of electromagnetic field decreased the spermatogenesis. Our findings warrant further investigations on the potential effects of EMF from mobile phones on male fertility.

Open access paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5896334/

May 2, 2016

By the end of 2013, 100 million cell phones in the U.S. operated on LTE. This number worldwide is expected to exceed 1 billion by the end of this year. 

Following is a summary of the second study published on the effects of 4th generation LTE cell phone radiation on the brain activity of cell phone users by the China Academy of Telecommunication Research of the Ministry of Industry and Information Technology.

 The original study showed that 30 minutes of exposure to LTE phone radiation affected brain activity in the left superior temporal gyrus, left middle temporal gyrus, right superior temporal gyrus, right medial frontal gyrus and right paracentral lobule. The current study found that a 30-minute exposure to LTE radiation modulated the EEG in the alpha and beta bands at the frontal region of the near and remote sides, and at the temporal region on the near side.

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Long-Term Evolution EMF Exposure Modulates Resting State EEG on Alpha and Beta Bands

Yang L, Chen Q, Lv B, Wu T. Long-Term Evolution Electromagnetic Fields Exposure Modulates the Resting State EEG on Alpha and Beta Bands. Clin EEG Neurosci. 2017 May;48(3):168-175. doi: 10.1177/1550059416644887.

Abstract

Long-term evolution (LTE) wireless telecommunication systems are widely used globally, which has raised a concern that exposure to electromagnetic fields (EMF) emitted from LTE devices can change human neural function. To date, few studies have been conducted on the effect of exposure to LTE EMF. Here, we evaluated the changes in electroencephalogram (EEG) due to LTE EMF exposure. An LTE EMF exposure system with a stable power emission, which was equivalent to the maximum emission from an LTE mobile phone, was used to radiate the subjects. Numerical simulations were conducted to ensure that the specific absorption rate in the subject's head was below the safety limits. Exposure to LTE EMF reduced the spectral power and the interhemispheric coherence in the alpha and beta bands of the frontal and temporal brain regions. No significant change was observed in the spectral power and the inter-hemispheric coherence in different timeslots during and after the exposure. These findings also corroborated those of our previous study using functional magnetic resonant imaging.

http://1.usa.gov/2475GM3

 Excerpts

".. the results of resting state EEG experiments have been contradictory. For example, some studies have reported enhancement of the alpha (8-12 Hz) and beta (13-30 Hz) band power values after exposure to pulse-modulated 450- and 900-MHz signals, pulse-modulated magnetic fields, and active mobile phone signals. In contrast, some studies have shown decreased alpha band activity after 20 minutes of extremely low-frequency EMF exposure, or 5 minutes of magnetic field exposure, or global system for mobile communications (GSM) EMF exposure. Many studies also found no changes in the EEG after either modulated or unmodulated EMF exposure. These inconsistencies could be attributed not only to the differences in the signal type, the modulation, the exposure frequency, the exposure intensity individual anatomy, the ages of the subjects, and the exposure duration but also to the lack of rigorous experimental designs. Most of the previously published studies have focused on GSM, WiFi, and Universal Mobile Telecommunications System (UMTS), signals. An emerging technology, “long term evolution” (LTE) wireless service, has been deployed since 2009 and the number of global LTE subscribers is expected to reach 1.37 billion by the end of 2015. Other than our previous functional magnetic resonance imaging (fMRI) study, there are very few reports on the effect of exposure to LTE EMF on brain function. We previously found that 30 minutes of exposure to LTE EMF modulated the spontaneous low-frequency fluctuations. We were interested in confirming our previous results using another neurophysiological method and also sought to assess the evolution of the effect over time during such exposure. In this article, we have investigated for the first time the changes in the resting state EEG caused by exposure to LTE signals. The exposure dose was below the current safety limit. In order to assess brain activities on different levels, we evaluated spectral power and interhemispheric coherence, which allowed investigation of EEG changes in specific brain regions, as well as their correlations, at different time points. We show that exposure to LTE EMF decreased the alpha and beta band power spectrum and interhemisphere coherence."

"The age of the subjects was 30.2 ± 2.7 years."

"A plastic spacer of 1 cm was used to maintain the distance between the right ear and a standard dipole. We applied 2 power meters to ensure a constant incident power to the emission dipole. The power delivered to the dipole was 24 dBm (peak value), equivalent to a theoretical maximum emission by an LTE terminal."

"All 25 subjects participated in the double-blind and counterbalanced experiment."

"The experiment included 2 sessions, which were separated by 1 week. Each session lasted 50 minutes and comprised 5 time slots. We indicated each time slot (10 minutes) in a session as sub1 to sub5. The radiation dipole was power off for the first (preexposure, sub1) and the last 10 minutes (postexposure, sub5) timeslots. Subjects were exposed to real EMF exposure in the 3 time slots (sub2 to sub4) between the first and the last 10 minutes in only 1 of the 2 sessions. The order of the 2 sessions was randomly selected per subject. The subjects were not informed of the sequence of each session; however, they were aware of the possibility of being exposed. On the other hand, the staff who analyzed the data did not know the sources of the EEG traces."

"The simulations yielded 1.34 W/kg (pSAR10g) and 1.96 W/kg (pSAR1g), with the electrodes, and 1.27 W/kg (pSAR10g) and 1.78 W/kg (pSAR1g), without the electrodes (Figure 2) when the dipole emitted radiation. Therefore, the presence of the EEG electrodes increased pSAR10g and pSAR1g by about 5.5% and 10.1%, respectively. Accordingly, the maximum resultant temperature increase was no more than 0.1°C ...."

"Previous studies on GSM and UMTS signal exposure frequently reported changes in interhemispheric coherence and the spectral power in the alpha band in the frontal and temporal regions, which were also confirmed by our results on LTE EMF exposure. Moreover, modulation of the power spectrum in the beta band, including both an increase and a decrease, was reported. Several reasons may account for the inconsistency. First, the signal frequency and its modulation influenced the affected EEG band: for example, exposure to 2G signals affect the alpha rhythms, whilst exposure to 3G signals do not. In contrast, the modulated 450-MHz signals of various intensities can change beta activity much more markedly than alpha band power. Second, gender and the individual sensitivity 38,40 may influence the effect on different bands. Hence, we attempted to reduce the variability by enrolling the subjects with the same gender and age."

"In particular, power spectral analysis has shown significant differences in the left frontal brain regions, that is, the remote side, on exposure. This may be associated with modulation of neural activity in the remote/contralateral brain regions. The remote effects of EMF have been observed in many previous studies. Our results reconfirmed that the effects were also seen with LTE EMF exposure."

"The power spectrum and the interhemispheric coherence did not differ significantly over sub2 to sub5. Thus, the observed effect did not change with the exposure time and the effect was therefore not developing. The reduction in alpha band activity has been associated with a decrease in individual information-processing ability, alertness, and cognitive performance. The decrease in beta band activity could be interpreted as decreased alertness, arousal, and excitement or a low level of fatigue. Notably, EEG power fluctuation was not in one-one correspondence with the change in behavioral/cognitive performance which should be evaluated by specifically designed experiments as the report by Haarala et al. No conclusion could be obtained by our study that the present EMF exposure affected the subjects’ cognitive abilities."

"This work studied EEG changes caused by LTE EMF exposure. An exposure system with a fixed power incident to a radiation dipole was used; this simulation demonstrated that the SAR was within the safety limits. LTE EMF exposure modulated the EEG in the alpha and beta bands at the frontal region of the near and remote sides, and at the temporal region on the near side. No developing effect was found in the periods during and after the exposure. Our results agreed to some extent with those of our previous fMRI study on LTE exposure. Our finding indicated that the LTE EMF exposure with the intensity beneath the safety limits could modulate the brain activities."

"Future studies should focus on the correlation of EEG changes with spatial SAR distribution. By taking individual anatomical structure into consideration, a precise dose-effect relationship can be established. EEG changes with a finer temporal resolution during the exposure session should also be evaluated."

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The alteration of spontaneous low frequency oscillations caused by acute electromagnetic fields exposure

Lv B, Chen Z, Wu T, et al. The alteration of spontaneous low frequency oscillations caused by acute electromagnetic fields exposure. Clin Neurophysiol. 2014;125:277-286.

Abstract

OBJECTIVE: The motivation of this study is to evaluate the possible alteration of regional resting state brain activity induced by the acute radiofrequency electromagnetic field (RF-EMF) exposure (30 minutes) of Long Term Evolution (LTE) signal.

 METHODS: We designed a controllable near-field LTE RF-EMF exposure environment. Eighteen subjects participated in a double-blind, crossover, randomized and counterbalanced experiment including two sessions (real and sham exposure). The radiation source was close to the right ear. Then the resting state fMRI signals of human brain were collected before and after the exposure in both sessions. We measured the amplitude of low frequency fluctuation (ALFF) and fractional ALFF (fALFF) to characterize the spontaneous brain activity.

 RESULTS: We found the decreased ALFF value around in left superior temporal gyrus, left middle temporal gyrus, right superior temporal gyrus, right medial frontal gyrus and right paracentral lobule after the real exposure. And the decreased fALFF value was also detected in right medial frontal gyrus and right paracentral lobule.

 CONCLUSIONS: The study provided the evidences that 30 minute LTE RF-EMF exposure modulated the spontaneous low frequency fluctuations in some brain regions.

 SIGNIFICANCE: With resting state fMRI, we found the alteration of spontaneous low frequency fluctuations induced by the acute LTE RF-EMF exposure.

https://www.ncbi.nlm.nih.gov/pubmed/24012322
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