Effects of radiofrequency electromagnetic field (RF-EMF) exposure on male fertility: A systematic review of experimental studies on non-human mammals and human sperm in vitro.

BACKGROUND: The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Reproductive health outcomes have been identified among the priority topics to be addressed. OBJECTIVES: To evaluate the effect of RF-EMF exposure on male fertility of experimental mammals and on human sperm exposed in vitro. METHODS: Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 17, 2022. Two independent reviewers screened the studies, which were considered eligible if met the following criteria: 1) Peer-reviewed publications of sham controlled experimental studies, 2) Non-human male mammals exposed at any stage of development or human sperm exposed in vitro, 3) RF-EMF exposure within the frequency range of 100 kHz-300 GHz, including electromagnetic pulses (EMP), 4) one of the following indicators of reproductive system impairment:Two reviewers extracted study characteristics and outcome data. We assessed risk of bias (RoB) using the Office of Health Assessment and Translation (OHAT) guidelines. We categorized studies into 3 levels of overall RoB: low, some or high concern. We pooled study results in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses. For experimental animal studies, we conducted subgroup analyses for species, Specific Absorption Rate (SAR) and temperature increase. We grouped studies on human sperm exposed in vitro by the fertility status of sample donors and SAR. We assessed the certainty of the evidence using the GRADE approach after excluding studies that were rated as "high concern" for RoB. RESULTS: One-hundred and seventeen papers on animal studies and 10 papers on human sperm exposed in vitro were included in this review. Only few studies were rated as "low concern" because most studies were at RoB for exposure and/or outcome assessment. Subgrouping the experimental animal studies by species, SAR, and temperature increase partly accounted for the heterogeneity of individual studies in about one third of the meta-analyses. In no case was it possible to conduct a subgroup analysis of the few human sperm in vitro studies because there were always 1 or more groups including less than 3 studies. Among all the considered endpoints, the meta-analyses of animal studies provided evidence of adverse effects of RF-EMF exposure in all cases but the rate of infertile males and the size of the sired litters. The assessment of certainty according to the GRADE methodology assigned a moderate certainty to the reduction of pregnancy rate and to the evidence of no-effect on litter size, a low certainty to the reduction of sperm count, and a very low certainty to all the other meta-analysis results. Studies on human sperm exposed in vitro indicated a small detrimental effect of RF-EMF exposure on vitality and no-effect on DNA/chromatin alterations. According to GRADE, a very low certainty was attributed to these results. The few studies that used EMP exposure did not show effects on the outcomes. A low to very low certainty was attributed to these results. DISCUSSION: Many of the studies examined suffered of severe limitations that led to the attribution of uncertainty to the results of the meta-analyses and did not allow to draw firm conclusions on most of the endpoints. Nevertheless, the associations between RF-EMF exposure and decrease of pregnancy rate and sperm count, to which moderate and low certainty were attributed, are not negligible, also in view of the indications that in Western countries human male fertility potential seems to be progressively declining. It was beyond the scope of our systematic review to determine the shape of the dose-response relationship or to identify a minimum effective exposure level. The subgroup and the dose-response fitting analyses did not show a consistent relationship between the exposure levels and the observed effects. Notably, most studies evaluated RF-EMF exposure levels that were higher than the levels to which human populations are typically exposed, and the limits set in international guidelines. For these reasons we cannot provide suggestions to confirm or reconsider current human exposure limits. Considering the outcomes of this systematic review and taking into account the limitations found in several of the studies, we suggest that further investigations with better characterization of exposure and dosimetry including several exposure levels and blinded outcome assessment were conducted. PROTOCOL REGISTRATION: Protocols for the systematic reviews of animal studies and of human sperm in vitro studies were published in Pacchierotti et al., 2021. The former was also registered in PROSPERO (CRD42021227729 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID = 227729) and the latter in Open Science Framework (OSF Registration DOI https://doi.org/10.17605/OSF.IO/7MUS3).

Effects of Radiofrequency Electromagnetic Field (RF-EMF) exposure on pregnancy and birth outcomes: A systematic review of experimental studies on non-human mammals.

BACKGROUND: The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Within the project, 6 topics have been prioritized by an expert group, which include reproductive health outcomes. OBJECTIVES: According to the protocol published in 2021, a systematic review and meta-analyses on the adverse effects of RF-EMF exposure during pregnancy in offspring of experimental animals were conducted. METHODS: Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 8 or 17, 2022. Based on predefined selection criteria, the obtained references were screened by two independent reviewers. Studies were included if they met the following criteria: 1) original, sham controlled experimental study on non-human mammals exposed in utero, published in peer-reviewed journals, 2) the experimental RF-EMF exposure was within the frequency range 100 kHz-300 GHz, 3) the effects of RF-EMF exposure on fecundity (litter size, embryonic/fetal losses), on the offspring health at birth (decrease of weight or length, congenital malformations, changes of sex ratio) or on delayed effects (neurocognitive alterations, female infertility or early-onset cancer) were studied. Study characteristics and outcome data were extracted by two reviewers. Risk of bias (RoB) was assessed using the Office of Health Assessment and Translation (OHAT) guidelines. Study results were pooled in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses, after exclusion of studies that were rated at "high concern" for RoB. Subgroup analyses were conducted for species, Specific Absorption Rate (SAR) and temperature increase. The certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. RESULTS: Eighty-eight papers could be included in this review. Effects on fecundity. The meta-analysis of studies on litter size, conducted at a whole-body average SAR of 4.92 W/kg, did not show an effect of RF-EMF exposure (MD 0.05; 95% CI -0.21 to 0.30). The meta-analysis of studies on resorbed and dead fetuses, conducted at a whole-body average SAR of 20.26 W/kg, showed a significant increase of the incidence in RF-EMF exposed animals (OR 1.84; 95% CI 1.27 to 2.66). The results were similar in the dose-response analysis. Effects on the offspring health at birth. The meta-analysis of studies on fetal weight, conducted at a whole-body average SAR of 9.83 W/kg, showed a small decrease in RF-EMF exposed animals (SMD 0.31; 95% CI 0.15 to 0.48). The meta-analysis of studies on fetal length, conducted at a whole-body average SAR of 4.55 W/kg, showed a moderate decrease in length at birth (SMD 0.45; 95% CI 0.07 to 0.83). The meta-analysis of studies on the percentage of fetuses with malformations, conducted at a whole-body average SAR of 6.75 W/kg, showed a moderate increase in RF-EMF exposed animals (SMD -0.45; 95% CI -0.68 to -0.23). The meta-analysis of studies on the incidence of litters with malformed fetuses, conducted at a whole-body average SAR of 16.63 W/kg, showed a statistically significant detrimental RF-EMF effect (OR 3.22; 95% CI 1.9 to 5.46). The results were similar in the dose-response analyses. Delayed effects on the offspring health. RF-EMF exposure was not associated with detrimental effects on brain weight (SMD 0.10; 95% CI -0.09 to 0.29) and on learning and memory functions (SMD -0.54; 95% CI -1.24 to 0.17). RF-EMF exposure was associated with a large detrimental effect on motor activity functions (SMD 0.79; 95% CI 0.21 to 1.38) and a moderate detrimental effect on motor and sensory functions (SMD -0.66; 95% CI -1.18 to -0.14). RF-EMF exposure was not associated with a decrease of the size of litters conceived by F2 female offspring (SMD 0.08; 95% CI -0.39 to 0.55). Notably, meta-analyses of neurobehavioural effects were based on few studies, which suffered of lack of independent replication deriving from only few laboratories. DISCUSSION: There was high certainty in the evidence for a lack of association of RF-EMF exposure with litter size. We attributed a moderate certainty to the evidence of a small detrimental effect on fetal weight. We also attributed a moderate certainty to the evidence of a lack of delayed effects on the offspring brain weight. For most of the other endpoints assessed by the meta-analyses, detrimental RF-EMF effects were shown, however the evidence was attributed a low or very low certainty. The body of evidence had limitations that did not allow an assessment of whether RF-EMF may affect pregnancy outcomes at exposure levels below those eliciting a well-known adverse heating impact. In conclusion, in utero RF-EMF exposure does not have a detrimental effect on fecundity and likely affects offspring health at birth, based on the meta-analysis of studies in experimental mammals on litter size and fetal weight, respectively. Regarding possible delayed effects of in utero exposure, RF-EMF probably does not affect offspring brain weight and may not decrease female offspring fertility; on the other hand, RF-EMF may have a detrimental impact on neurobehavioural functions, varying in magnitude for different endpoints, but these last findings are very uncertain. Further research is needed on the effects at birth and delayed effects with sample sizes adequate for detecting a small effect. Future studies should use standardized endpoints for testing prenatal developmental toxicity and developmental neurotoxicity (OECD TG 414 and 426), improve the description of the exposure system design and exposure conditions, conduct appropriate dosimetry characterization, blind endpoint analysis and include several exposure levels to better enable the assessment of a dose-response relationship. PROTOCOL REGISTRATION AND PUBLICATION: The protocol was published in Pacchierotti et al., 2021 and registered in PROSPERO CRD42021227746 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=227746).

In Vivo Studies on Radiofrequency (100 kHz-300 GHz) Electromagnetic Field Exposure and Cancer: A Systematic Review.

The increasing exposure of the human population to radiofrequency electromagnetic fields has increased concern about its possible health effects. The aim of this systematic review is to provide an update of the state of the research on this topic, through a quantitative analysis, to assess the increased risk of tumor incidence in laboratory animals (rodents) without limitations of species, strain, sex or genotype. The review was conducted according to the PRISMA guideline and individual studies were assessed by referring to the OHAT Risk of Bias Rating Tool for Human and Animal Studies. A total of 27 studies were considered eligible for the evaluation of tumor incidence; a meta-analysis was carried out on 23 studies to assess the possible increased risk of both malignant and benign tumors onset at the systemic level or in different organs/tissues. A significant association between exposure to RF and the increased/decreased risk of cancer does not result from the meta-analysis in most of considered tissues. A significant increased/decreased risk can be numerically observed only in heart, CNS/brain, and intestine for malignant tumors. Nevertheless, the assessment of the body of evidence attributes low or inadequate evidence for an association between RF exposure and the onset of neoplasm in all tissues.

Melanoma metastásico en intestino delgado: causa infrecuente de perforación: reporte de caso / Metastatic melanoma in the small intestine: infrequent cause of perforation: case report / Melanoma metastático em intestino delgado: causa rara de perfuração: relato de caso

El intestino delgado es el sitio de asiento más frecuente del melanoma metastásico. Su diagnóstico es un desafío por cursar asintomático o con síntomas inespecíficos. Son pocos los casos que presentan complicaciones, siendo infrecuente la peritonitis por perforación. El objetivo del trabajo es comunicar el caso clínico de una peritonitis por perforación de una metástasis de melanoma en intestino delgado. Caso clínico: Paciente de sexo masculino de 66 años con diagnóstico de melanoma de cuello y secundario óseo, encefálico y pulmonar, fue intervenido de urgencia por peritonitis aguda por perforación de metástasis en intestino delgado. El estudio histológico confirmó secundarismo de melanoma cutáneo. Conclusión: Sabiendo que el yeyuno íleon es el sitio de asiento más frecuente de las metástasis de melanoma, ante la presencia de síntomas digestivos inespecíficos o anemia se debe sospechar su compromiso y evaluar posibles alternativas terapéuticas.

The small intestine is the most frequent site of metastatic melanoma. However, its diagnosis continues to be a challenge since it is usually asymptomatic or with non-specific symptoms. Few cases result in complications, peritonitis due to perforation being infrequent. The objective of the work is to report a clinical case of peritonitis due to perforation of a melanoma metastasis in the small intestine. Clinical case: A 66-year-old male patient diagnosed with melanoma of the neck and secondary bone, brain and lung melanoma, underwent emergency surgery for acute peritonitis due to perforation of metastasis in the small intestine, which was resected and anastomosed. The histology confirmed the secondary nature of the cutaneous melanoma. Conclusion: Knowing that the jejunum-ileum is the most frequent site of melanoma metastases, in the presence of non-specific digestive symptoms or anemia, its involvement should be suspected and possible therapeutic alternatives should be evaluated.

O intestino delgado é o local mais frequente de melanoma metastático. O diagnóstico é um desafio por ser assintomático ou apresentar sintomas inespecíficos. Há poucos casos que apresentam complicações, sendo pouco frequente a peritonite por perfuração. O objetivo deste trabalho é relatar um caso clínico de peritonite por perfuração de metástase de melanoma no intestino delgado. Caso clínico: Paciente do sexo masculino, 66 anos, diagnosticado com melanoma no pescoço com metástase óssea, cefálica e pulmonar. Foi submetido a cirurgia de emergência por peritonite aguda por perfuração de metástases do intestino delgado. O estudo histológico confirmou melanoma cutâneo. Conclusão: Sabendo que o jejuno e o íleo é o local mais frequente de metástase de melanoma, na presença de sintomas digestivos inespecíficos ou anemia deve-se suspeitar de seu acometimento e avaliar possíveis alternativas terapêuticas.

Protocol for a systematic review of the in vivo studies on radiofrequency (100 kHz-300 GHz) electromagnetic field exposure and cancer.

BACKGROUND: An Italian project aims to review the scientific literature on the possible carcinogenicity of radiofrequency (100 kHz-300 GHz) electromagnetic field (RF-EMF) exposure. The ENEA team has to carry out a systematic review of the in vivo studies on this topic. OBJECTIVES: Development of a protocol for a systematic review (meta-analysis included) to investigate the potential carcinogenic risk following RF-EMF in vivo exposure to doses above or within legal limits. The aims of this review are (1) to provide a descriptive and, if possible, a quantitative summary of the results of the examined RF-EMF in vivo studies, together with an assessment of the consistency of observations and of the causes of heterogeneity, and (2) to assess the weight of evidence to support or refute the hypothesis of carcinogenic effects caused by RF-EMF exposure and to draw conclusions about the potential for carcinogenicity of RF-EMF exposure. METHODS: We will search for relevant studies in electronic academic databases and in the reference list of selected papers and reviews on the topic, including the descriptive reviews on RF-EMF carcinogenic effect carried out by international panels of experts since 2011. The following elements of the PECO question were defined: experimental studies on rodents of both sexes, all ages and species, all genetic backgrounds (Population) exposed to RF-EMF alone, or in combination with other physical or chemical agents (Exposure); only studies reporting outcome data in exposed and sham control groups (Comparison); and all types of cancer with all tumor-related outcome measures (Outcome) will be included. Only peer-reviewed articles written in English will be considered without limit in the publication date. Eligibility criteria were defined for papers to be included. A risk of bias assessment will be performed using a tool specifically developed for animal studies. A meta-analysis will be performed, if feasible, for all outcome measures; for subgroup analysis, a minimum of 3 studies per subgroup will be required. If meta-analysis will not be possible, a narrative synthesis of the results will be reported. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020191105 HIGHLIGHTS: An Italian collaborative research agreement aims to review the scientific literature on the possible carcinogenicity of RF-EMF (100 kHz - 300 GHz). The ENEA team will systematically review and, if possible, meta-analyse estimates the effects of in vivo exposure to RF-EMF exposure on cancer. The ENEA group is a multidisciplinary team of researchers with a consolidated experience both in carcinogenicity experiments and radiofrequency dosimetric assessment. The proposed protocol uses the NTP OHAT Approach for Systematic Review as an organizing framework. The proposed protocol aims to lead to the first systematic review providing a strength of evidence assessment on this topic.

Effects of Radiofrequency Electromagnetic Field (RF-EMF) exposure on male fertility and pregnancy and birth outcomes: Protocols for a systematic review of experimental studies in non-human mammals and in human sperm exposed in vitro.

BACKGROUND: Radiofrequency Electromagnetic Fields (RF-EMF) at environmental level have been reported to induce adverse effects on the male reproductive system and developing embryos. However, despite the number of experiments conducted since the 1970s, the diversity of testing approaches and exposure conditions, inconsistencies among results, and dosimetric flaws have not yet permitted a solid assessment of the relationship between RF-EMF exposure and such effects, warranting a more systematic and methodologically rigorous approach to the evaluation of available data. OBJECTIVES: This study aims at evaluating the effects of RF-EMF exposure on male fertility and pregnancy outcomes by a systematic review (SR) of experimental studies, conducted in compliance with international guidelines. The evidence will be organized into three streams: 1) Studies evaluating the impact of RF-EMF on the male reproductive system of experimental mammals; 2) studies evaluating the impact of RF-EMF on human sperm exposed in vitro; 3) studies evaluating the impact of RF-EMF on adverse pregnancy, birth outcomes and delayed effects in experimental mammals exposed in utero. STUDY ELIGIBILITY AND CRITERIA: Eligible studies will include peer-reviewed articles reporting of original results about effects of controlled exposures to RF-EMF in the frequency range 100 kHz-300 GHz on the selected outcomes without any language or year-of-publication restrictions. Eligible studies will be retrieved by calibrated search strings applied to three electronic databases, PubMed, Scopus and EMF Portal and by manual search of the list of references of included papers and published reviews. STUDY APPRAISAL AND SYNTHESIS METHOD: The internal validity of the studies will be evaluated using the Risk of Bias (RoB) Rating Tool developed by National Toxicology Program/Office of Health Assessment and Translation (NTP/OHAT) integrated with input from the SYRCLE RoB tool. Given sufficient commensurate data, meta-analyses will be performed, otherwise narrative syntheses will be produced. Finally, the certainty of the effects of RF-EMF exposure on male fertility and pregnancy and birth outcomes will be established following GRADE. FUNDING: The study is financially supported by the World Health Organization. REGISTRATION: OSF Registration DOI https://doi.org/10.17605/OSF.IO/7MUS3; PROSPERO CRD42021227729, CRD42021227746.

Effect of radiofrequency electromagnetic field exposure on in vitro models of neurodegenerative disease.

In this work we tested viability, proliferation, and vulnerability of neural cells, after continuous radiofrequency (RF) electromagnetic fields exposure (global system for mobile telecommunications (GSM) modulated 900 MHz signal at a specific absorption rate (SAR) of 1 W/kg and maximum duration 144 h) generated by transverse electromagnetic cells. We used two cellular systems, SN56 cholinergic for example, SN56 cholinergic cell line and rat primary cortical neurons, and well-known neurotoxic challenges, such as glutamate, 25-35AA beta-amyloid, and hydrogen peroxide. Exposure to RF did not change viability/proliferation rate of the SN56 cholinergic cells or viability of cortical neurons. Co-exposure to RF exacerbated neurotoxic effect of hydrogen peroxide in SN56, but not in primary cortical neurons, whereas no cooperative effects of RF with glutamate and 25-35AA beta-amyloid were found. These data suggest that only under particular circumstances exposure to GSM modulated, 900 MHz signal act as a co-stressor for oxidative damage of neural cells.

Continuous exposure to 900MHz GSM-modulated EMF alters morphological maturation of neural cells.

The effects of radiofrequency electromagnetic field (RF-EMF) exposure on neuronal phenotype maturation have been studied in two different in vitro models: murine SN56 cholinergic cell line and rat primary cortical neurons. The samples were exposed at a dose of 1W/kg at 900 MHz GSM modulated. The phenotype analysis was carried out at 48 and 72 h (24 and 48 h of SN56 cell line differentiation) or at 24, 72, 120 h (2, 4 and 6 days in vitro for cortical neurons) of exposure, on live and immunolabeled neurons, and included the morphological study of neurite emission, outgrowth and branching. Moreover, cortical neurons were studied to detect alterations in the expression pattern of cytoskeleton regulating factors, e.g. beta-thymosin, and of early genes, e.g. c-Fos and c-Jun through real-time PCR on mRNA extracted after 24h exposure to EMF. We found that RF-EMF exposure reduced the number of neurites generated by both cell systems, and this alteration correlates to increased expression of beta-thymosin mRNA.

A radio-frequency system for in vivo pilot experiments aimed at the studies on biological effects of electromagnetic fields.

An exposure system consisting of two long transversal electromagnetic (TEM) cells, operating at a frequency of 900 MHz, is presented and discussed. The set-up allows simultaneous exposure of a significant number of animals (up to 12 mice per cell) in a blind way to a uniform plane wave at a frequency of 900 MHz, for investigating possible biological effects of exposure to electromagnetic fields produced by wireless communication systems. A heating/refrigerating system has also been designed for maintaining comfortable environmental conditions within the TEM cells during experiments. An accurate dosimetric study has been performed both numerically and by means of direct measurements on phantoms and living mice. The results have shown that good homogeneity of exposure and adequate power efficiency, in terms of whole-body specific absorption rate (SAR) per 1 W of input power, are achievable for the biological target.

Determinants of exposure to electromagnetic fields from mobile phones.

In actual conditions of use, the power radiated from cellular phones changes during conversation depending on several factors. Upon request from the radio base station (RBS), the phone in fact, reduces, its power to a level that is deemed optimum for the quality of conversation. In this study, special phones, which had been modified to allow the continuous logging of power emitted during the calls have been used. Off-line processing of recorded data allowed the analysis of the behaviour of mobile phones under real-use conditions. Further data recorded by operators at selected base stations were used for the purposes of comparison and checking of the effectiveness of the experimental method. The results indicate a high proportion of use of the highest power levels, under any circumstance. Such behaviour is mainly due to frequent handovers requested by the control software to optimise the communication traffic.