Uncertainty Analysis of Mobile Phone Use and Its Effect on Cognitive Function: The Application of Monte Carlo Simulation in a Cohort of Australian Primary School Children

The effects of radiofrequency exposure on cognition: A systematic review and meta-analysis of human observational studies

BACKGROUND

We aimed to assess evidence of long-term effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) on indicators of cognition, including domains of learning and memory, executive function, complex attention, language, perceptual motor ability and social cognition, and of an exposure-response relationship between RF-EMF and cognition.

METHODS

We searched PubMed, Embase, PsycInfo and the EMF-Portal on September 30, 2022 without limiting by date or language of publication. We included cohort or case-control studies that evaluated the effects of RF exposure on cognitive function in one or more of the cognitive domains. Studies were rated for risk of bias using the OHAT tool and synthesised using fixed effects meta-analysis. We assessed the certainty of the evidence using the GRADE approach and considered modification by OHAT for assessing evidence of exposures.

RESULTS

We included 5 studies that reported analyses of data from 4 cohorts with 4639 participants consisting of 2808 adults and 1831 children across three countries (Australia, Singapore and Switzerland) conducted between 2006 and 2017. The main source of RF-EMF exposure was mobile (cell) phone use measured as calls per week or minutes per day. For mobile phone use in children, two studies (615 participants) that compared an increase in mobile phone use to a decrease or no change were included in meta-analyses. Learning and memory. There was little effect on accuracy (mean difference, MD -0.03; 95% CI -0.07 to 0.02) or response time (MD -0.01; 95% CI -0.04 to 0.02) on the one-back memory task; and accuracy (MD -0.02; 95%CI -0.04 to 0.00) or response time (MD -0.01; 95%CI -0.04 to 0.03) on the one card learning task (low certainty evidence for all outcomes). Executive function. There was little to no effect on the Stroop test for the time ratio ((B-A)/A) response (MD 0.02; 95% CI -0.01 to 0.04, very low certainty) or the time ratio ((D-C)/C) response (MD 0.00; 95% CI -0.06 to 0.05, very low certainty), with both tests measuring susceptibility to interference effects. Complex attention. There was little to no effect on detection task accuracy (MD 0.02; 95% CI -0.04 to 0.08), or response time (MD 0.02;95% CI 0.01 to 0.03), and little to no effect on identification task accuracy (MD 0.00; 95% CI -0.04 to 0.05) or response time (MD 0.00;95% CI -0.01 to 0.02) (low certainty evidence for all outcomes). No other cognitive domains were investigated in children. A single study among elderly people provided very low certainty evidence that more frequent mobile phone use may have little to no effect on the odds of a decline in global cognitive function (odds ratio, OR 0.81; 95% CI 0.42 to 1.58, 649 participants) or a decline in executive function (OR 1.07; 95% CI 0.37 to 3.05, 146 participants), and may lead to a small, probably unimportant, reduction in the odds of a decline in complex attention (OR 0.67;95%CI 0.27 to 1.68, 159 participants) and a decline in learning and memory (OR 0.75; 95% CI 0.29 to 1.99, 159 participants). An exposure-response relationship was not identified for any of the cognitive outcomes.

DISCUSSION

This systematic review and meta-analysis found only a few studies that provided very low to low certainty evidence of little to no association between RF-EMF exposure and learning and memory, executive function and complex attention. None of the studies among children reported on global cognitive function or other domains of cognition. Only one study reported a lack of an effect for all domains in elderly persons but this was of very low certainty evidence. Further studies are needed to address all types of populations, exposures and cognitive outcomes, particularly studies investigating environmental and occupational exposure in adults. Future studies also need to address uncertainties in the assessment of exposure and standardise testing of specific domains of cognitive function to enable synthesis across studies and increase the certainty of the evidence.

OTHER

This review was partially funded by the WHO radioprotection programme and prospectively registered on PROSPERO CRD42021257548.

Instruments to measure environmental and personal radiofrequency-electromagnetic field exposures: an update

Modern human populations are exposed to anthropogenic sources of radiofrequency-electromagnetic fields (RF-EMFs), primarily to telecommunication and broadcasting technologies. As a result, ongoing concerns from some members of the public have arisen regarding potential health effects following RF-EMF exposures. In order to monitor human RF-EMF exposures and investigate potential health effects, an objective assessment of RF-EMF exposures is necessary. Accurate dosimetry is essential for any investigation of potential associations between RF-EMF exposure and health effects in human populations. This review updates state-of-the-art knowledge of currently available RF-EMF exposure assessment tools applicable in human epidemiological studies. These tools cater for assessing RF-EMF exposures in human environments; through mobile phone-based tools or other standalone tools. RF-EMF exposure assessment has been significantly improved through the application of some of these tools in recent years.

Systematic review of the physiological and health-related effects of radiofrequency electromagnetic field exposure from wireless communication devices on children and adolescents in experimental and epidemiological human studies

BACKGROUND

For more than 20 years, the potential health risks of radiofrequency electromagnetic field (RF EMF) exposure from mobile communication devices on children and adolescents have been examined because they are considered sensitive population groups; however, it remains unclear whether such exposure poses any particular risk to them.

OBJECTIVES

The aim of this review was to systematically analyze and evaluate the physiological and health-related effects of RF EMF exposures from wireless communication devices (mobile phones, cordless phones, Bluetooth, etc.) on children and adolescents.

METHODS

This review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Methodological limitations in individual studies were assessed using the Office of Health Assessment and Translation (OHAT) Risk-of-Bias Rating Tool for Human and Animal Studies.

RESULTS

A total of 42 epidemiological and 11 experimental studies were eligible for this review. Most of the studies displayed several methodological weaknesses that limited the internal validity of the results. Due to a lack of consistency regarding the outcomes as well as the lack of scientific rigor in most reviewed studies, the body of evidence for the effects of RF EMF of mobile communication devices on subjective symptoms, cognition, and behavior in children and adolescents was low to inadequate. Evidence from the studies investigating early childhood development, brain activity, cancer, and physiological parameters was considered inadequate for drawing conclusions about possible effects.

DISCUSSION

Overall, the body of evidence allows no final conclusion on the question whether exposure to RF EMF from mobile communication devices poses a particular risk to children and adolescents. There has been rapid development in technologies generating RF EMF, which are extensively used by children and adolescents. Therefore, we strongly recommend high-quality systematic research on children and adolescents, since they are generally considered as sensitive age groups.

Hokkaido birth cohort study on environment and children's health: cohort profile 2021

BACKGROUND

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary objectives are to (1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including birth defects and growth retardation; (2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development; (3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) identify the additive effects of various chemicals, including tobacco.

METHODS

The purpose of this report is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions. In particular, this report provides the latest details from questionnaire surveys, face-to-face examinations, and a collection of biological specimens from children and measurements of their chemical exposures.

RESULTS

The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, leptin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies.

CONCLUSIONS

Chemical exposure to children can occur both before and after birth. Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. This study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.

Exposure to Radiofrequency Electromagnetic Field in the High-Frequency Band and Cognitive Function in Children and Adolescents: A Literature Review

With increasing use of mobile phones, exposure to radiofrequency electromagnetic field (RF-EMF) in the high-frequency band associated with mobile phones has become a public concern, with potentially adverse effects on cognitive function in children and adolescents. However, findings regarding the relation of RF-EMF and cognitive function in children and adolescents have been inconsistent due to a number of study design-related factors, such as types of exposure and outcome measures, age of participants, and the era of study conduction. The present literature review focused on these possible factors that could explain this inconsistency. This review identified 12 eligible studies (participants ages 4 to 17 years) and extracted a total 477 relations. In total, 86% of the extracted relations were not statistically significant; in the remaining 14%, a negative relation between RF-EMF and cognitive performance was detected under limited conditions: when (1) RF-EMF was assessed using objective measurement not subjective measurement (i.e., questionnaire), (2) participants were relatively older (12 years and above) and had greater opportunity of exposure to RF-EMF, and (3) the collection of cognitive function data was conducted after 2012. Given that 86% of the extracted relations in this analysis were not statistically significant, the interpretation should be approached with caution due to the possibility of the 14% of significant relationships, extracted in this review, representing chance findings.