7 October 2024

23 September 2023

Literature review date

September 2024

Article publication date

July 2024

Summary

This systematic review and meta-analysis examined the effect of radiofrequency electromagnetic energy (RF EME) on cognitive performance in human experimental studies. The review included 50 studies in the meta-analysis (2,433 participants) from 15 countries that were conducted between 2001 and 2021. It assessed cognitive performance of five (of the 7) cognitive domains (Orientation and attention, Perception, Memory, Construction and motor performance, and Concept formation and reasoning), including 19 (of 35) cognitive domain subclasses as defined by Lezak et al (2004). Each subclass was assessed based on the speed and accuracy of the participant performing tasks associated with that particular subclass (attentional capacity, concentration, etc). Most of the included studies used 2G-era mobile phone RF EME as the exposure source. Certainty of evidence and risk of bias were also evaluated according to OHAT-GRADE approach. 

The authors reported no statistically significant results, indicating that RF-EME exposure has not impact on cognitive performance on human in experimental studies for all of the 19 subclasses tested. However, the certainty in these results ranged from high to low. Three of the 19 subclasses were not able to be tested for both speed and accuracy. Of 35 meta-analyses performed on the subclasses, a majority (20) of them provided high certainty of evidence that RF EME exposure results in little to no difference in cognitive outcome. The evidence on the effect of RF EME on the remaining 16 subclasses of the cognitive domains was uncertain. This uncertainty was due to limitations in the study quality, inconsistency in the results or imprecision of the combined effect size estimate. Overall, the review reported no evidence that RF EME exposure impacts cognitive performance. 

Link to

The effect of exposure to radiofrequency electromagnetic fields on cognitive performance in human experimental studies: Systematic review and meta-analyses

Published in

Environment International 

ARPANSA commentary

The overall conclusion of the review was that RF EME exposure does not impact cognitive performance in human experimental studies. This systematic review is the most comprehensive that has been published on this topic as it considered all cognitive domains and people of all ages. Other recent reviews and meta-analyses have had similar outcomes (Valentini et al, 2010; Barth et al ,2011; Zubko et al, 2017) reporting no impact of mobile phone frequencies on short term cognitive performance. However, these studies only examined a few cognitive domains including, attention, processing speed and working memory. Further, these reviews did not assess the quality or risk of bias of their included studies in the same manner as this systematic review. For example, Barth et al (2011) performed no quality assessment; Valentini et al (2010) used a simple assessment that assessed the blinding, participant selection, exposure assessment and statistics used. Zubko et al (2017) did use the risk of bias tool developed by OHAT, however, it did not assess the certainty of the evidence according to the GRADE approach. 

This review is part of the World Health Organization’s (WHO) ongoing project assessing the health effects of RF-EMF. ARPANSA is supporting this WHO review process. One of the WHO systematic reviews has examined the long-term impacts on cognition of RF EME exposure (Benke et al 2024). This review was conducted in Australia and was co-led by ARPANSA scientists. This systematic review also reported that RF EME had no consistent impact on cognition.

Overall, the results from this systematic review are consistent with previous research and ARPANSA’s scientific understanding that exposure to RF EME below the limits in the ARPANSA RF safety standard do not cause health impacts, including cognitive outcomes.

2 September 2024

4 September 2024

29 August 2024

Article review date

August 2024

Article publication date

July 2024

Summary

This meta-analysis of cohort studiesevaluated the current evidence on the association between occupational exposure to ionising radiation and risk of thyroid cancer. A total of six studies published between 2006 and 2021, which had a total of 420,543 participants, 6,322 cases and a mean follow-up period of 23 years, were included in the analysis. Data on radiation exposure levels (in Gray (Gy) or mSv) were available for almost all studies; whereas the information on thyroid cancer was largely based on clinical (i.e., histopathological) diagnosis except two studies which had self-reported diagnosis. The associations between ionising radiation exposure (i.e., personal or estimated thyroid doses)  and thyroid cancer were examined in terms of risk ratio (RR) with 95% confidence interval (CI). Quality assessment of the included studies was also conducted according to the Newcastle-Ottawa Scale (NOS). The results showed that the five included studies had reported the occupational radiation exposure doses (individual doses or estimated thyroid doses), which ranged from 10.4 to 500 mGy or <0.20 to 7.2 mSv. Occupational radiation exposure was associated with the risk of thyroid cancer (RR=1.61, 95% CI: 1.27‑2.04). Sex-wise sensitivity analysis further showed that males with the history of occupational radiation exposure (compared to females) tend to be at a slightly higher risk of developing thyroid cancer (RR=1.74, 95% CI: 1.61‑1.87 vs. RR=1.30, 95% CI: 1.15‑1.48). Overall, the evidence from the meta-analysis indicates that occupational exposure to ionising radiation was associated with the risk of thyroid cancer. 

Published in

Oncology Letters

Link to study

Occupational radiation exposure and risk of thyroid cancer: A meta‑analysis of cohort studies 

Commentary by ARPANSA

The meta-analysis provides the latest risk estimate of thyroid cancer risk among occupationally exposed human populations to ionising radiation. These findings are consistent with those of a previous pooled analysis of seven studies (Ron et al, 1995); however, contrary to those reported in a previous case-control study (Fincham et al, 2000). Similarly, the findings that males tend to have higher risk of developing thyroid cancer is contrary to the findings of a latest study (Khoramian et al., 2024) reporting higher thyroid cancer risk among females (compared to males) undergoing head CT imaging. No similar data are available to compare these findings in the Australian context. A key limitation of the current meta-analysis is that the available data in the included studies did not allow a detailed subgroup analysis of the occupation type, dose‑effect and time‑effect relationship. Further, the meta-analysis doesn't provide any information on the exposure contrast, so it is difficult to determine whether the exposure metrics that were used in the meta-analysis from the different studies were appropriate. Though quality of a majority of the included studies in the meta-analysis was high, they had a considerable heterogeneity (I²=84%) resulting in between-study variance.

In Australia, The Code for Radiation Protection in Planned Exposure Situations  sets out the requirements for the protection of occupationally exposed persons in all planned exposure situations. All Australian jurisdictions have uniform annual limits (20 mSv) for occupational exposure to ionising radiation. In addition to the dose limits, optimisation of radiation protection and safety involves practising ‘as low as reasonably achievable (ALARA) considering economic and societal factors.

Article review date

August 2024

Article publication date

July 2024

ARPANSA summary

This study aimed to investigate the efficacy of public health messaging in relation to sun protection when using appearance-based or health-based messages. The study recruited 95 participants (aged 17-24 years) who first completed a questionnaire on their sun protection behaviour and knowledge. The participants were then shown one of six possible text messages and their sun protection intentions were evaluated. Each of the six text messages tried a different strategy to appeal to the study participants. The messages either contained information on melanoma health risk, methods of sun protection, the cosmetic consequences of surgical melanoma removal or a combination thereof. The results showed that none of the messages affected the sun protection intentions of the participants compared to a control message indicating no significant difference between any of the interventions. Outside of the intervention evaluations, the survey found a gender-gap in sunbathing behaviour where 26% of male participants sunbathed compared to 60% of female participants. 

Link to study

Sun safety in young Queensland adults: behaviours, knowledge, and responses to health-based and appearance-based text messages

Published in

Australian Psychologist

ARPANSA commentary

Ongoing sun protection campaigns in Australia like SunSmart continue to seek to improve the efficacy of their messaging, ultimately with the goal of reducing adverse health outcomes related to sun overexposure. Recent studies (Persson, S. et al., 2018; Mahler, H. 2015; Cheng, J. et al. 2018) have indicated that appealing to concerns about appearance may be more effective than appealing to concerns about health risk and this direction has been partially adopted by some newer sun protection campaigns. 

The present study did not add significantly to this discussion as neither the health-based nor appearance-based messages had an effect compared to the control. The use of a single intra-survey text message to deliver the intervention and the absence of follow-up behaviour evaluations were highlighted as major limitations that contributed to the ineffectiveness shown. The authors also identified several other limitations with their study including low statistical power for the number of conditions that were tested and a gender imbalance among the study participants. It should also be noted that the appearance-based messaging in the study focused on surgical scarring from melanoma excisions, whereas other studies have focused primarily on skin photo-aging. This difference, although subtle, is significant as photo-aging is a much more deterministic outcome compared to melanoma and related treatments.

Whenever the UV-index is over three, ARPANSA recommends protecting yourself from the sun by following the five sun protection principles. More information about the risks of sun exposure and methods of sun protection can be found from: The World Health Organization, The Cancer Council of Australia and SunSmart websites. 

Article review date

August 2024

Article publication date

August 2024

ARPANSA summary

This prospective cohort study examined the association between exposure to radiofrequency electromagnetic energy (RF-EME) from the use of Wi-Fi, cordless and mobile phones, and behavioural problems among children. The study included 2,465 children (aged 8-17 years) from the Hokkaido Study on Environment and Children's Health. Data on the use of Wi-Fi, cordless and mobile phones was collected from parent-child dyads at baseline (October 2020-January 2021). Data on the children’s behavioural problems were collected at baseline and follow-up (September 2021-March 2022) via a Strength and Difficulties Questionnaire (SDQ). The children were categorized into four groups of composite measure of behaviour stability: normal (i.e., no difficulty at baseline and follow-up), persistent (borderline/clinical at baseline and follow-up), improved (borderline/clinical at baseline and normal follow-up), and concurrent (normal at baseline and borderline/clinical at follow-up). The association between RF-EME and different behavioural problems in children were estimated in terms of odds ratio (OR) with 95% confidence interval (CI).

No overall statistically significant association was found between RF-EMF exposure from Wi-Fi, cordless or mobile phone calls via mobile networks, and behavioural problems.  Conducting phone calls via the internet for over 40 minutes weekly had an increased risk (OR 2.01; 95% CI:1.14–3.57) for concurrent total difficulty scores. Mobile phone audio-streaming between 60 to 120 minutes weekly had a reduced risk (OR 0.53; 95% CI:0.30–0.93) for persistent total difficulty score. Cordless phone use was associated with higher odds (OR 1.88; 95% CI:1.24–2.85) of improved total difficulty scores. 

Link to study

Link between Wi-Fi, cordless devices, mobile phone usage patterns, and behavioral problems among Japanese children: A prospective cohort study

Published in

Environmental Research

ARPANSA commentary

The study largely showed that no association was found between Wi-Fi, mobile phone calls via mobile networks, and behavioural problems. However, there were a few sporadic findings showing both positive and negative effects. It is likely that these may have been affected by confounding or chance findings. A major limitation of the study is that the data on the uses of Wi-Fi and mobile and cordless phones were self-reported or reported by a parent on behalf of their child, which results in recall bias and an inaccurate estimation of the effect. Another major limitation is that any effects arising from RF-EME exposure could not be distinguished from effects that result from the activities themselves (e.g., texting, gaming/streaming and social media use). 

Overall the results of the study are consistent with the findings of the latest World Health Organization review and two Australian studies  (Bhatt et al., 2017; Thomas et al., 2011). The effect exposure to RF-EME sources on cognition has been reviewed by the International Commission on Non-Ionising Radiation Protection (ICNIRP) in their 2020 guidelines and they concluded that there is no substantiated experimental or epidemiological evidence that exposure to RF-EME affects cognition.  Overall, there remains no consistent scientific evidence that exposure to RF-EME below the limits set in ARPANSA safety standard, which is aligned with the ICNIRP guidelines, is a hazard to human health.