Article review date
26 October 2024
Article publication date
18 November 2024
Summary
This systematic review and narrative synthesis examined the evidence of genotoxic effects of radiofrequency electromagnetic fields (RF-EMF) on mammalian cells in vitro. The authors identified 159 articles eligible for inclusion in the review. Results from the included studies were grouped by genotoxicity endpoint and summary statistics that describe the results qualitatively were produced. Risk of bias and certainty of evidence evaluations were conducted according to OHAT-GRADE, although certainty of evidence assessments only considered studies that showed a statistically significant effect.
The reviewers found that, in 80% of all experiments, RF-EMF exposure did not induce statistically significant effects on the analysed endpoint. Spindle disturbances (90%), chromatin condensation (63%) and 8-OH-dG adducts (57%) were the only endpoints where the majority of experiments reported significant effects, however, the total number of experiments for these endpoints was small. The restricted certainty of evidence assessments found that there was low to very low confidence in the articles that did report a statistically significant effect. The review concludes that RF exposure probably does not increase the occurrence of genotoxic effects in vitro.
The risk of bias ratings were also used to identify an inverse relationship between study quality and the proportion of experiments reporting an effect, where low quality studies reported more statistically significant effects. Similarly, the experiments with the lowest exposure levels and durations reported the most amount of statistically significant outcomes, contrary to what is expected for an ordinary dose-response relationship.
Published in
Environment International
Link to study
Systematic review on the effects of RF-EMF on genotoxicity in mammalian cells
ARPANSA commentary
The conclusions of the review are in alignment with those of past reviews (Karipidis et al., 2021) however, these conclusions are based on a qualitative synthesis only as limitations in the body of evidence unfortunately precluded a more informative meta-analysis. The primary reason for this was that the majority of studies presented data in an unextractable graphical format only. A lack of dedicated guidelines for systematic reviews on mechanistic types of evidence, in vitro studies in this case, also hindered the review process. Due to the shortcomings of narrative synthesis, the reviewers are restricted in the level of detail they can include in their conclusions about health endpoints. The most important outcomes from this review are therefore the evaluations of the relationship between studies reporting significant effects and study quality.
GRADE certainty of evidence evaluations are typically used to evaluate evidence for health endpoints that are studied by the review. In this review’s implementation they restricted this analysis to studies that showed a statistically significant effect and assessed four of the eight categories defined in the GRADE methodology. The result is that the evidence assessments are an evaluation of the quality of studies that show a statistically significant effect, instead of an evaluation of certainty in the body of evidence for the health outcome. The finding that there is low to very low confidence in the studies showing a statistically significant effect in conjunction with the observed relationship between risk of bias and significant effects lends credibility to the overarching conclusion of the review that RF-EMF exposure probably does not increase the occurrence of genotoxic effects in vitro.
An ARPANSA review (Wood et al., 2021) has previously identified a similar negative correlation between effect size and study quality as well as between effect size and RF exposure level. This was also identified in a recent systematic review (Meyer et al., 2024) on the effects on RF-EMF on biomarkers of oxidative stress that ARPANSA has previously reviewed.
