Review date
July 2024
Article publication date
June 2024
Summary
This systematic review and meta-analysis examined the effect of radiofrequency electromagnetic fields (RF-EMF) on male fertility as reported in human observational studies. The reviewers screened over twenty thousand articles that were identified in their literature search and ultimately included nine studies in the final review. Of the nine studies, seven related to mobile phone use and two studies related to occupational RF-EMF exposure (from radar or communications transmitters). The analysis of male fertility indicators for these two groups was performed separately. The fertility indicators that were considered were sperm concentration (amount), morphology (size, shape) and motility (movement) as well as total sperm count and time to pregnancy. Analysis on mobile phone use was further segmented by ‘duration of phone use’ and phone position (e.g., amount of time phone is kept in front pocket). The review also conducted certainty of evidence and risk of bias evaluations according to OHAT-GRADE.
Only four meta-analyses were possible on RF-EMF exposure from mobile phone use and each showed little to no effect on fertility outcomes. Each of these analyses were rated as very low certainty evidence. These ratings were mainly due to inconsistency and indirectness of the included studies resulting from poor exposure characterisation and outcome assessments. For outcomes where a meta-analysis was not possible, including those relating to the effect of phone position, all but one of the included studies reported no statistically significant effects. The study describing an effect presented a negative relation between mobile phone use and sperm total motility. However, this result is weakened by very poorly classified exposure (measured by the total years participants had been using mobile phones and then grouped for comparison) and further weakened by probable selective reporting bias.
No meta-analysis was possible for occupational exposure due to large differences in the types of RF-EMF exposures between the two included studies. These studies reported a statistically significant difference in sperm concentration, motility and morphology for workers that were exposed compared to those who were not exposed. The authors cautioned against drawing overarching conclusions on occupational exposures from these findings due to the high risk of bias ratings for these studies and low amount of total data available on occupational exposures.
Link to
Published in
Environment International
Commentary by ARPANSA
The review concluded that the currently available evidence on the effect of RF-EMF exposure on male fertility indicates little evidence of an association. However, the review also noted very low certainty of evidence and high risk of bias associated with the available evidence. Notably, the characterisation of exposure (e.g., phone call duration or self-reported usage) was highlighted as a major limitation of the currently available studies, introducing bias and uncertainty in the evidence. These crude surrogate exposure measures have also been highlighted as major limitations in other recent studies (Benke et al., 2024; Feychting et al., 2024; Röösli et al., 2024).
There are notable problems with study selection in this review. The inclusion criteria in both the study methods and the registered protocol state that only epidemiological studies with a cohort or case-control design were to be included in the review. Despite this, several of the included studies use a cross-sectional study design. Cross-sectional study design is not suitable for this topic because the lack of a time-resolved connection between exposure and an adverse fertility outcome precludes the establishment of causality. In addition, one of the included studies is a conference abstract, meaning that it does not contain complete information about the study and has not been peer-reviewed. Both flaws are significant enough to warrant the exclusion of these studies from the evidence base used in the review and their exclusion may impact the meta-analysis. However, due to very low certainty of evidence reported for each meta-analysis, it is unlikely to have a large impact on the overarching conclusions.
Closer inspection of detail in the review reveals a slew of mismatches between the text of the review and the tables. The review refers to studies that are not present in the corresponding tables and figures and reciprocally, there are studies in the review’s tables that are not found in the text, reference list or PRISMA diagram. There are similar inconsistencies between separate tables. Although these shortcomings are unlikely to change the conclusions of the review, they complicate its interpretation and degrade the overall quality. Together with the inclusion criteria issues discussed above, this has negative implications for the importance of the review in the overarching scientific discourse on RF-EMF and male fertility.
The International Commission on Non-Ionising Radiation Protection (ICNIRP) has also reviewed the effect of RF-EMF on fertility, concluding that there was no adverse effect of RF-EMF on human fertility, reproduction, or development. Overall, there remains no substantiated scientific evidence that exposure to RF-EMF below the limits set in ARPANSA safety standard or the ICNIRP guidelines are a hazard to human fertility.
This review is part of the World Health Organization’s ongoing project assessing the health effects of RF-EMF (SR3 – Adverse reproductive outcomes (human observational studies)). ARPANSA is supporting this WHO review process. Another of these WHO reviews covered studies on male fertility in vitro and in non-human mammals which ARPANSA has reviewed in a previous literature survey. A systematic review of female fertility and reproductive outcomes has been published as a separate review by the same authors.
