Does evening exposure to mobile phone radiation affect subsequent melatonin production?

Disrupted Circadian Rhythms and Substance Use Disorders: A Narrative Review

Substance use disorder is a major global health concern, with a high prevalence among adolescents and young adults. The most common substances of abuse include alcohol, marijuana, cocaine, nicotine, and opiates. Evidence suggests that a mismatch between contemporary lifestyle and environmental demands leads to disrupted circadian rhythms that impair optimal physiological and behavioral function, which can increase the vulnerability to develop substance use disorder and related problems. The circadian system plays an important role in regulating the sleep-wake cycle and reward processing, both of which directly affect substance abuse. Distorted substance use can have a reciprocal effect on the circadian system by influencing circadian clock gene expression. Considering the detrimental health consequences and profound societal impact of substance use disorder, it is crucial to comprehend its complex association with circadian rhythms, which can pave the way for the generation of novel chronotherapeutic treatment approaches. In this narrative review, we have explored the potential contributions of disrupted circadian rhythms and sleep on use and relapse of different substances of abuse. The involvement of circadian clock genes with drug reward pathways is discussed, along with the potential research areas that can be explored to minimize disordered substance use by improving circadian hygiene.

Problematic smartphone use and mental health outcomes among Singapore residents: The health and lifestyle survey

BACKGROUND

The excessive use of smartphones and its association with adverse outcomes has been widely reported, with several studies showing an association between smartphone overuse, depression, anxiety, and sleep-related problems.

METHODS

The study used data from the Health and Lifestyle Survey, a nationwide population survey. It examined the prevalence of Problematic Smartphone Use (PSU) and its association with mental health outcomes among Singapore residents aged 15-65 years.

PARTICIPANTS

Participants were assessed for PSU using the Smartphone Addiction Scale-Short Version, psychological distress with the Patient Health Questionnaire-9, and Generalised Anxiety Disorder -7 questionnaire, sleep problems using the Insomnia Severity Index, and positive mental health with Rapid Positive Mental Health Instrument.

RESULTS

In all, 6509 participants completed the survey, giving a survey response rate of 73.2 %. The prevalence of PSU was 30.2 % in the population. Individuals with PSU were more likely to have symptoms of moderate or severe depression (OR: 3.2, 95 % CI: 2.4-4.4), anxiety (OR: 3.4, 95 % CI: 2.4-4.8), insomnia (OR: 3.4, 95 % CI: 2.8-4.2), and poorer positive mental health (β: -0.3, 95 % CI: -0.4 to -0.2).

CONCLUSIONS

The study is the first to examine PSU in a national sample of Singaporeans across a wide age range. It provides valuable insights into mental health comorbidities among those with PSU, which is useful for practitioners.

The relationship between mobile phone addiction and depression, anxiety, and sleep quality in medical students

This study investigates the prevalence of mobile phone addiction among medical students and its relationship with depression, anxiety, and sleep quality. The study was conducted at Mashhad University of Medical Sciences from 2019 to 2021, and it included medical students at four different levels of training. Participants were selected using a stratified random sampling method. All subjects completed the Mobile Phone Addiction Scale, Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory, and Beck Anxiety Inventory through online electronic self-report questionnaires. Overall, 355 medical students were included in the study, with 203 (57.2%) being female. Mild and severe mobile phone addiction was reported by 83.7 and 2.5% of the students, respectively. Furthermore, the study's findings revealed significantly higher sleep quality disorder, depression, and anxiety scores among students with severe mobile phone addiction compared to other participants ( P  < 0.001, P  = 0.007, and P  < 0.001, respectively). Although mobile phone addiction was prevalent, severe addiction was rare among medical students. Nevertheless, severe addiction was associated with an increased prevalence of mental health problems and sleep disturbances, emphasizing the importance of interventions aimed at reducing mobile phone addiction and improving mental health.

Effect of short video addiction on the sleep quality of college students: chain intermediary effects of physical activity and procrastination behavior

Introduction

The purpose of this study was to examine the impact of short video addiction on college students' sleep quality and to elucidate the mechanism underlying this relationship. Thus, we examined the correlation between short video addiction and sleep quality and analyzed the roles of physical activity and procrastination.

Methods

The Short Video Addiction Scale, Pittsburgh Sleep Quality Index, Aitken Procrastination Inventory, and Physical Activity Rating Scale were administered to 337 college students. Data were analyzed using SPSS 27.0. Pearson's correlation analysis and mediation analysis using the bootstrapping test were performed for the standard method bias test.

Results

(1) Overall, 25.2% of college students had problems with sleep quality (indicated by a PSQI score ≥ 8). (2) Short video addiction score is positively correlated with college students' sleep quality score; procrastination score was positively associated with both short video addiction score and sleep quality score, and physical activity score was negatively associated with them. (3) Short video addiction significantly positive predicted sleep quality (β = 0.458, P < 0.001), a significant negative predictive effect on physical exercise (β = -0.183, P < 0.001), and a significant positive effect on procrastination behavior (β = 0.246, P < 0.001). After physical exercise and procrastination behavior were entered into the regression equation, short video addiction and procrastination were significantly positive predictors of sleep quality, and physical activity was significantly negative predictor of sleep quality. (4) After accounting for the variables of age, gender, and grade, physical activity and procrastination behaviors independently mediated the association between short-video addiction and sleep quality. Physical activity and procrastination behavior acted as chain mediators in the association between short video addiction and sleep quality, with a chain mediation effect percentage of 1.04%. Short video addiction directly affects college students' sleep quality, indirectly through physical activity and procrastination behavior.

Effect of Smartphone Use on Sleep in Undergraduate Medical Students: A Cross-Sectional Study

Smartphone use, particularly at night, has been shown to provoke various circadian sleep-wake rhythm disorders such as insomnia and excessive daytime tiredness. This relationship has been mainly scrutinized among patient groups with higher rates of smartphone usage, particularly adolescents and children. However, it remains obscure how smartphone usage impacts sleep parameters in adults, especially undergraduate college students. This study sought to (1) investigate the association between smartphone use (actual screen time) and four sleep parameters: Pittsburgh sleep quality score (PSQI), self-reported screen time, bedtime, and rise time; (2) compare the seven PSQI components between good and poor sleep quality subjects. In total, 264 undergraduate medical students (aged 17 to 25 years) were recruited from the Government Doon Medical College, Dehradun, India. All participants completed a sleep questionnaire, which was electronically shared via a WhatsApp invitation link. Hierarchical and multinomial regression analyses were performed in relation to (1) and (2). The average PSQI score was 5.03 ± 0.86, with approximately one in two respondents (48.3%) having a poor sleep index. Smartphone use significantly predicted respondents' PSQI score (β = 0.142, p = 0.040, R2 = 0.027), perceived screen time (β = 0.113, p = 0.043, R2 = 343), bedtime (β = 0.106, p = 0.042, R2 = 045), and rise time (β = 0.174, p = 0.015, R2 = 0.028). When comparing poor-quality sleep (PSQI ≥ 5) to good-quality sleep (PSQI < 5), with good-quality sleep as the reference, except sleep efficiency and sleep medications (p > 0.05), five PSQI components declined significantly: subjective sleep quality (β = -0.096, p < 0.001); sleep latency (β = -0.034, p < 0.001); sleep duration (β = -0.038, p < 0.001); sleep disturbances (β = 1.234, p < 0.001); and sleep dysfunction (β = -0.077, p < 0.001). Consequently, public health policymakers should take this evidence into account when developing guidelines around smartphone use-i.e., the when, where, and how much smartphone use-to promote improved sleep behaviour and reduce the rate of sleep-wake rhythm disorders.

Ubiquitous light-emitting diodes: Potential threats to retinal circadian rhythms and refractive development

The use of light-emitting diodes (LEDs) has increased considerably in the 21st century with humans living in a modern photoperiod with brighter nights and dimmer days. Prolonged exposure to LEDs, especially at night, is considered a new source of pollution because it may affect the synthesis and secretion of retinal melatonin and dopamine, resulting in negative impacts on retinal circadian clocks and potentially disrupting retinal circadian rhythms. The control of ocular refraction is believed to be related to retinal circadian rhythms. Moreover, the global prevalence of myopia has increased at an alarming rate in recent decades. The widespread use of LEDs and the rapid increase in the prevalence of myopia overlap, which is unlikely to be a coincidence. The connection among LEDs, retinal circadian rhythms, and refractive development is both fascinating and confusing. In this review, we aim to develop a systematic framework that includes LEDs, retinal circadian rhythms and refractive development. This paper summarizes the possible mechanisms by which LEDs may disrupt retinal circadian rhythms. We propose that prolonged exposure to LEDs may induce myopia by disrupting retinal circadian rhythms. Finally, we suggest several possible countermeasures to prevent LED interference on retinal circadian rhythms, with the hope of reducing the onset and progression of myopia.

Association between Physical Activity, Sedentary Behavior, Satisfaction with Sleep Fatigue Recovery and Smartphone Dependency among Korean Adolescents: An Age- and Gender-Matched Study

The purpose of this study was to identify the association between physical activity (PA), sedentary behavior (SB), satisfaction with sleep fatigue recovery (SSFR), and smartphone dependency in South Korean adults. We analyzed data from the National Health and Nutrition Examination Survey 2020 data. We selected participants who answered Internet addiction-related questions as “Very much” (n = 241) and answered Internet addiction-related questions as “Not at all” (n = 241) in the questionnaire. The participants were matched by age and gender, then divided into two groups. Between the two groups, there were considerable differences in the number of days participating in moderate to vigorous PA (5 days or more, p = 0.01), the number of strength training days (1 day, p = 0.02), the number of light PA days for more than 60 min (every day for the last 7 days, p = 0.01), and the SSFR over the past 7 days (p < 0.05). Additionally, the mean smartphone usage time and mean sedentary behavior time between the two groups showed significant differences. The study demonstrated that there were significant associations between PA, SB, SSFR, and smartphone dependency among Korean adolescents matched by age and gender. Additionally, this study highlights the importance of increasing overall PA and number of days participating in MVPA, decreasing SB time and smartphone usage time could reduce the incidence of smartphone overdependence.

Mobile phone addiction and depressive symptoms among Chinese University students: The mediating role of sleep disturbances and the moderating role of gender

Background

With the continuous updating of mobile phone functions, the phenomenon of mobile phone addiction among University students is becoming more and more serious. It is important to identify the potential risk factors for mobile phone addiction. The aim of the study was to examine whether there is a relationship between mobile phone addiction and depression symptoms in University students, and to investigate whether sleep disturbances play a mediating role between mobile phone addiction and depression symptoms, as well as the moderating role of gender.

Methods

A cross-sectional study, carried out between September to December 2021, recruited 973 students (478 males) from seven comprehensive universities in western China. The Mobile Phone Addiction Index (MPAI), the Patient Health Questionnaire-9 (PHQ9), and the Pittsburgh Sleep Quality Index (PSQI) were used to complete measures of mobile phone addiction, depressive symptoms, and sleep disturbances. For statistical analyses, descriptive statistics, correlation, regression, mediation and moderated mediation analyses were used. Furthermore, we tested the mediation model and moderated mediation model using the SPSS macro PROCESS.

Results

In this study, it was found that there were positive correlations between mobile phone addiction and depressive symptoms among Chinese University students. Mediation analyses revealed that this relationship was partially mediated by sleep disturbances, but the mediating role was not moderated by gender.

Conclusion

Sleep disturbances have a partial mediating role in the relationship between mobile phone addiction and depressive symptoms. Our results highlight the critical role of prevention and early identification of mobile phone addiction among University students, especially those with sleep disturbances.

Characteristics of Sleep Patterns in Adolescents: Comparisons between Saudi Arabia and the UK

There are concerns regarding sleep deprivation among adolescents, especially with mounting evidence for the importance of sleep during puberty, and its effects on health and families. The present study aimed to characterise sleep in typical development (TD) adolescents in Saudi Arabia, and compare their sleep profiles to TD adolescents in the UK, to evaluate sleep patterns in adolescents in Saudi Arabia, and to examine the relationship between sleep patterns and the use of social media in both groups. Findings from the current study reported a shorter sleep duration for the Saudi Arabia group than in previous studies and the UK group, which may be attributed to the lack of sleep hygiene practised in Saudi Arabia. Multiple analysis of variance results found significant differences in daytime sleepiness (p < 0.001) and a preference for morningness/eveningness (p < 0.001) between Saudia Arabia and UK adolescents. Statistically significant negative correlations (p > 0.05) between the duration of social media usage and sleep duration were found in both the Saudi Arabia and UK adolescents, where a lower number of sleep hours was observed with a higher duration of social media use. This study fills a gap in the research of sleep in Saudi Arabia in adolescents, and offers important insights on the comparison in sleep habits between Saudi Arabia and UK adolescents.

The Relationship between Duration of Smartphone Uses and Anxiety in University Students during the COVID-19 Outbreak

Background: During the COVID-19 pandemic, China adopted a home isolation policy, which caused lifestyle changes for university students, including increased smartphone use. Several studies indicate that problematic smartphone use is associated with anxiety. However, this association has not been examined in the context of epidemics. The aim of this study was to investigate whether the duration of smartphone use was associated with anxiety in Chinese university students during the COVID-19 pandemic. Methods: Participants included 9716 university students (5458 men and 4258 women) from Liaoning, China. We assessed the duration of smartphone use with a self-reported questionnaire. Anxiety was assessed using the generalized anxiety disorder seven-item scale. A multivariate logistic regression analysis was performed to determine the adjusted association between smartphone use and anxiety. Results: After adjusting for confounding factors, we observed a positive association between smartphone use duration and the prevalence of anxiety in all participating students. Compared with short periods of smartphone usage, the odds ratios (95% confidence interval) for moderate and long smartphone usage duration were 1.17 (1.00, 1.36) and 1.58 (1.36, 1.83), respectively. This significant positive association did not change in the sex-stratified analysis (for both men and women). Conclusions: Our examination of the association between duration of smartphone uses and university students’ anxiety levels revealed that long smartphone use was associated with a high prevalence of anxiety during the COVID-19 pandemic.

Phubbing among Lebanese young adults: Scale validation and association with mental health (depression, anxiety, and stress)

Mobile phones use has not been without several social and psychological problems, specifically during the fast spread of the COVID-19 infection, which imposed strict restrictions and isolation. This research principal aims were to (1) confirm the validity of the Generic Scale of Phubbing in Arabic (GSP), and (2) evaluate the association between phubbing and mental health (depression, anxiety and stress). A first cross-sectional study enrolled 203 participants to confirm the factor structure of the phubbing scale among Lebanese young adults. A confirmatory factor analysis (CFA) was carried out on the whole sample using SPSS AMOS v.24 to confirm the four-factor structure of the GSP. The root mean square error of approximation (RMSEA) statistic, the comparative fit index (CFI) and the Tucker Lewis Index (TLI) were used to evaluate the goodness-of-fit of the model. RMSEA values ≤0.08 and ≤ 0.10 indicate a good and acceptable fit respectively. CFI and TLI values ≥0.90 indicate good model fit. A second cross-sectional study enrolled 461 respondents (18-29 years old) to conduct the multivariable analysis. The fit indices values were as follows: χ2/df = 181.74/84 = 2.16, TLI = .92, CFI = .94 and RMSEA = .076 [95% CI .061-.091] respectively, indicating an excellent fit of the model. The results of the multiple linear regression using the ENTER model, when taking the phubbing score as the dependent variable, showed that female gender (β = 0.11; t(454) = 2.50; p = .013), more stress (β = 0.27; t(454) = 3.94; p < .001), more anxiety (β = 0.30; t(454) = 4.24; p < .001), and older age (β = 0.28; t(454) = 6.12; p < .001) were positively correlated with higher phubbing, or higher household crowding index (β = -0.15; t(454) = -3.62; p < .001) was significantly correlated with less phubbing. The results of this study were able to confirm the validity of the Arabic version of the GSP scale. This will allow Lebanese clinicians to use this validated tool to screen for the presence of the phubbing phenomenon within this age group. We propose finding possible correlation between phubbing and others factors (such as obsession and loneliness) and validating this scale in other Arabic-speaking countries.

Using Structural Equation Modeling to Examine Pathways between Physical Activity and Sleep Quality among Chinese TikTok Users

TikTok, the most popular social media, brings various benefits to nowadays living. However, the problematic use of TikTok has also elicited a range of health problems, such as sleep problems. Physical activity (PA) appears to play a protective role in the problematic use of TikTok and its health consequences, but the pathways between PA and sleep health are understudied. Therefore, we aimed to propose a framework to check whether PA can benefit the sleep health of TikTok users by reducing bedtime delays for TikTok. Stress and mental health issues were also considered as they are potential mediators between PA and sleep health and may also influence the problematic use of smartphones. A cross-sectional investigation that involved 660 Chinese TikTok users was conducted in April 2021. The volume of PA, perceived stress (PSS-10), depression (PHQ-9), anxiety (GAD-7), bedtime delay for TikTok use, and sleep quality (PSQI) were investigated through an online questionnaire survey. Structural equation modeling was employed to examine pathways from PA to sleep quality through stress, mental health issues (depression and anxiety), and bedtime delay for TikTok. We found that PA exerted a significant effect on sleep quality through indirect pathways (β = −0.056, p = 0.001). Stress was a critical mediator of all indirect pathways, and the pathway mediated by stress and mental health issues made a major contribution to the total effect (β = −0.048, p = 0.002). The identified pathways mediated by bedtime delay for TikTok were relatively weak but significant. PA showed a distinct effect on bedtime delay for TikTok through stress and mental health issues (β = −0.043, p = 0.001). In conclusion, our framework highlights some pathways to understanding the benefits of PA on TikTok users’ sleep quality. Future research is warranted to explore extra indirect pathways and re-examine the causal relationships between variables.

Relationships Between Internet Use and Sleep Duration in Chinese Adults: A Cross-Sectional Study

Purpose

Most studies that examined the relationship between internet use and sleep were conducted mainly in children and adolescents, and we know little about the use of internet among adults. The purpose of this study is to understand the internet use patterns of Chinese adults and to measure their associations with sleep duration from variety, frequency and type.

Methods

A total of 19,730 samples were selected from 2018 data of the China Health and Retirement Longitudinal study. Internet usage was obtained by specific questions, and the range of sleep period was grouped according to recommendations from the National Sleep Foundation. Kruskal–Wallis H-test and the chi-squared test were used for basic descriptive analysis, and multinomial logistic regression was used to analyze the relationships between internet use and sleep duration. Stata version 15.0 was used for data cleaning, and SPSS version 20.0 was used for statistics analysis.

Results

After screening, a total of 6346 persons were included in the analysis, of which 3148 (49.61%) were males and 3198 (50.39%) were females. Age ranged from 21 to 95 years, most persons were over 45 years old, with the median age of 56 years. Only 1180 (18.59%) participants used the internet, and almost all of them used mobile phones (1137, 96.36%), the other three types were desktop computer (232, 19.66%), laptop computer (69, 5.85%) and tablet (73, 6.19%). There were 912 (77.28%) and 268 (22.71%) participants who used only one and two or more types, respectively. In the unadjusted model, both short sleep and long sleep were associated with internet use compared with normal sleep duration (0.806 [0.708–0.918] p = 0.001; 0.345 [0.251–0.475] p < 0.000). After adjusting for all covariates, the association between long sleep and internet use still persisted (0.612 [0.433–0.865] p = 0.005), but no significant difference was found in short sleep (0.929 [0.803–1.075] p = 0.325).

Conclusion

Internet use was found to be closely associated with sleep and the duration of sleep negatively affected, which may provide new ideas for sleep hygiene recommendations and healthy media use. This conclusion needs more evidence to support.

An Investigation into Smartphone Addiction with Personality and Sleep Quality among University Students

Over the past two decades, smartphones have become common, and the accompanying devices have also become much more popular and easily accessible worldwide. With the development of smartphones, accompanied by internet facilities, excessive smartphone use or smartphone addiction may cause sleep disturbance and daily dysfunction. This study proposed examining the association between personality traits and smartphone addiction and its effects on sleep disturbance. Four hundred and twenty-two university participants (80 male and 342 female participants) with a mean age of 20.22 years old were recruited in this study. All participants were asked to complete the following questionnaires: Smartphone Addiction Inventory (SPAI), Tri-dimensional personality questionnaire (TPQ), and Chinese Pittsburgh Sleep Questionnaire Index (CPSQI). The results showed that people with a high tendency toward novelty seeking (NS) as a personality trait, compared to those with lower tendency toward NS, are more likely to become addicted to smartphone use. Moreover, those with a stronger trait of being NS and specific impulsivity factor were found to have higher total scores in the SPAI (p < 0.05). In addition, linear regression analysis showed that the individuals with higher scores for withdrawal symptoms on the SPAI and anticipatory worry factor on the TPQ tended to have higher CPSQI total scores (p < 0.05). This information may be useful for prevention in individuals with personality traits making them vulnerable to smartphone addiction and for designing intervention programs to reduce intensive smartphone use and programs to increase capability in managing smartphone use.

Daytime and nighttime smartphone use: A study of associations between multidimensional smartphone behaviours and sleep among 24,856 Danish adults

The around-the-clock smartphone use and its relation to disturbed sleep is a public health concern. The present study aimed to quantify the effects of different dimensions of smartphone behaviours (frequency of daytime use, problematic use, use before sleep and use during the sleep period) on disturbed sleep (sleep quality and sleep quantity) and to disentangle their inter-relationship in a large population-based sample of 24,856 Danish adults aged ≥16 years. Data come from the SmartSleep Experiment, which is a web-based survey carried out using a citizen science approach. Tested items were used to evaluate smartphone use and disturbed sleep was evaluated with the Karolinska Sleep Questionnaire (KSQ). Linear and multinomial logistic regression was employed to evaluate the relationship between smartphone use and disturbed sleep. While several of the smartphone measures were associated with disturbed sleep when assessed individually, smartphone use during the sleep period was the only dimension consistently associated with disturbed sleep when assessed independently of other smartphone behaviours. Weekly smartphone use during the sleep period versus no use was associated on average with a 0.96 point higher score (95% confidence interval [CI] 0.90-1.02) on the 5-point KSQ scale, and a higher risk of both short (odds ratio [OR] 1.32, 95% CI 1.08-1.62) and long (OR 1.94, 95% CI 1.63-2.32) sleep duration. Smartphone use during the sleep period is the factor strongest associated to disturbed sleep relative to other dimensions of smartphone use. Recommendations around smartphone use during the sleep period are warranted in order to protect the fundamentally important biological and mental processes of sleep.

Redefining electrosensitivity: A new literature-supported model

In critically examining literature on electrohypersensitivity and the reported somatic responses to anthropogenic modulated radiofrequency radiation (RFR) exposure, it becomes apparent that electrohypersensitivity is one part of a range of consequences. Current evidence on the necessity of considering patients' overall health status leads us to propose a new model in which electrohypersensitivity is but part of the electrosensitive status inherent in being human. We propose the likelihood and type of response to environmental RFR include i) a linear somatic awareness continuum, ii) a non-linear somatic response continuum, and iii) the extent of each individual's capacity to repair damage (linked to homeostatic response). We anticipate this last, dynamic, aspect is inextricably linked to the others through the autonomic nervous system. The whole is dependent upon the status of the interconnected immune and inflammatory systems. This holistic approach leads us to propose various outcomes. For most, their body maintains homeostasis by routine repair. However, some develop electrohypersensitivity either due to RFR exposure or as an ANS-mediated, unconscious response (aka nocebo effect), or both. We suggest RFR exposure may be one factor in the others developing an auto-immune disease or allergy. A few develop delayed catastrophic disease such as glioma. This model gives the blanket term ElectroMagnetic Illness (EMI) to all RFR-related conditions. Thus, EHS appears to be one part of a range of responses to a novel and rapidly changing evolutionary situation.

Nomophobia is Associated with Insomnia but Not with Age, Sex, BMI, or Mobile Phone Screen Size in Young Adults

PURPOSE

NOMOPHOBIA (NO MObile PHone PhoBIA) or problematic smartphone use is a psychological disorder in which people are afraid of being cut off from their mobile phones. Currently, there has been no direct assessment of mobile phone screen size in the home setting and its effect on nomophobia and related symptoms, such as insomnia. Thus, we investigated the association between nomophobia, insomnia, and mobile phone screen size in a young adult population in Bahrain.

PATIENTS AND METHODS

Using a descriptive, cross-sectional design, we surveyed participants aged 18 to 35 between August and September 2020 using an online questionnaire. Participants completed demographic questions and questions about personal mobile phones, the Nomophobia Questionnaire (NMP-Q), and the Insomnia Severity Index (ISI). The mobile phone screen size was determined using an open-source online database. Crude and adjusted regression analyses were fitted to examine the associations between the study variables.

RESULTS

A total of 549 individuals, 54% females, were included in the final analyses. One hundred and fourteen participants (21%) had severe nomophobia, and 81 (14%) had clinical insomnia. A strong positive pair-wise linear association was observed between NMP-Q and ISI β 0.15, P = 0.001. Age, sex, BMI, and mobile phone screen size showed no association with the NMP-Q.

CONCLUSION

Nomophobia is very prevalent in young adult men and women, and it is closely associated with insomnia, regardless of mobile phone screen size, suggesting that mobile phone screen size should not be used as a proxy for hazardous usage.

Interplay between social media use, sleep quality, and mental health in youth: A systematic review

Social media applications are increasingly prominent among youth. This systematic review provides a comprehensive assessment of the literature on the relationship between active social media use, sleep quality, and common mental health outcomes (anxiety, depression, and psychological distress) among youth. MEDLINE, PsychINFO, EMBASE and Scopus were searched for observational studies investigating this relationship among youth (aged 16-25). Thirty-six cross-sectional studies and six prospective cohort studies met the inclusion criteria. Among cross-sectional studies, significant associations between excessive social media use with poor mental health outcomes (n = 33), poor sleep quality (n = 24), and significant associations between poor sleep quality and negative mental health (n = 16) were found. In longitudinal studies, frequent social media use was a risk factor for both poor mental health (n = 6) and poor sleep outcomes (n = 5). Some studies showed sleep quality mediating the relationship between social media use and negative mental health outcomes in youth. Overall, included evidence links excessive social media use to poor sleep quality and negative mental health in youth. Given the public health implications of sleep problems, excessive social media use warrants further investigation to clarify the directionality and strength of their associations with poor sleep quality and negative mental health outcomes.

Association Between Mobile Phone Radiation Exposure and the Secretion of Melatonin and Cortisol, Two Markers of the Circadian System: A Review

The extremely important use of mobile phones in the world, at all ages of life, including children and adolescents, leads to significant exposure of these populations to electromagnetic waves of radiofrequency. The question, therefore, arises as to whether exposure to these radiofrequencies (RFs) could lead to deleterious effects on the body's biological systems and health. In the current article, we review the effects, in laboratory animals and humans, of exposure to RF on two hormones considered as endocrine markers: melatonin, a neurohormone produced by the pineal gland and cortisol, a glucocorticosteroid synthesized by the adrenal glands. These two hormones are also considered as markers of the circadian system. The literature search was performed using PubMed, Medline, Web of Sciences (ISI Web of Knowledge), Google Scholar, and EMF Portal. From this review on RF effects on cortisol and melatonin, it appears that scientific papers in the literature are conflicting, showing effects, no effects, or inconclusive data. This implies the need for additional research on higher numbers of subjects and with protocols perfectly controlled with follow-up studies to better determine whether the chronic effect of RF on the biological functioning and health of users exists (or not). Bioelectromagnetics. 2021;42:5-17. © 2020 Bioelectromagnetics Society.

Assessment of relationship between the use of cell phone and social networks and sleep quality in students of medical sciences: A cross-sectional study

Introduction

Sleep quality is an essential aspect in human health and function. Considering high prevalence of using smartphones and social networks among students and their impact on sleep quality, this study was conducted to determine the relationship between the overuse of cell phone and addiction to social networks and students’ sleep quality.

Materials and methods

This cross-sectional study was conducted in Kermanshah University of Medical Sciences, Kermanshah, Iran in 2018. Using cluster sampling, 321 students from different disciplines were selected. Data gathering tools consisted of the questionnaire of Pittsburgh Sleep Quality Index (PSQI). Cell phone use and addiction to social networks were assessed using Cell Phone Overuse Scale and a researcher-made questionnaire, respectively. Data were analyzed using SPSS software (version 19) and Pearson’s correlation test.

Results

The mean total score of sleep quality in students was 6.58 ± 1.05. There was a positive and significant correlation between sleep quality and social networks addiction score (p < 0.05, r = 0.5) and cell phone overuse (p < 0.05, r = 0.44); this is an inverse correlation, because higher scores of the total PSQI denote a lower sleep quality and, in Cell Phone Overuse Scale, higher scores shows overuse.

Conclusions

According to the findings of this study, there was a significant statistical relationship between the overuse of cell phone and social networks and students’ sleep quality. In other words, students who have had overuse of cell phones had poorer sleep quality. Therefore, providing effective educational programs to improve the sleep quality in this group is essential.

Exposure to light at night (LAN) and risk of obesity: A systematic review and meta-analysis of observational studies

BACKGROUND

There is emerging evidence of the association between light at night (LAN) exposure and weight gain.

OBJECTIVE

We aim to conduct a systematic review and meta-analysis of observational studies on the association between LAN exposure and risk of obesity in human subjects.

METHODS

Peer-reviewed observational studies were systematically searched from MEDLINE (EBSCO), Academic Search Complete (EBSCO), CINAHL Plus (EBSCO) and PubMed up to December 24, 2019. Random-effects models were developed to estimate the associations between LAN exposure and weight-related outcomes of overweight and obesity as measured by body mass index (BMI), waist circumference, waist-hip-ratio and waist-to-height-ratio. The I² statistic was used to assess the degree of heterogeneity across studies. The National Toxicology Program's Office of Health Assessment and Translation (OHAT) risk of bias rating tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guideline were respectively employed to assess the risk of bias and to appraise the quality of the generated evidence.

RESULTS

A total of 12 studies (three with longitudinal and nine of cross-sectional design) published between 2003 and 2019 were included for systematic review, while seven of them fulfilling the inclusion/exclusion criteria were included in the meta-analysis. A higher LAN exposure was significantly associated with 13% higher odds of overweight (BMI≥25 kg/m²) (Summary Odds Ratio; SOR: 1.13, 95% CI: 1.10-1.16) with low heterogeneity (I² = 27.27%), and 22% higher odds of obesity (BMI≥30 kg/m²) (SOR: 1.22, 95% CI: 1.07-1.38) with substantial heterogeneity (I² = 85.96%). Stratifying analyses by the levels of measurement of LAN exposures (macro-, meso- and micro-levels) and time of LAN measurement (including before and while sleeping) consistently produced robust estimates, with higher exposure to LAN being positively associated with poorer weight outcomes. Assessment of risk of bias identified substantial detection bias for exposure, with over half of the pooled studies employing subjective LAN measures. The overall evidence of the association between LAN exposure and risk of obesity was rated as 'moderate' as per the GRADE guideline.

CONCLUSIONS

Exposure to LAN was reported to be a significant risk factor for overweight and obesity. Prospectively designed future studies with objectively measured multi-level LAN exposures and weight outcomes are required.

[Mediators of Problematic Social Media Use in Adolescence as Possible Mechanisms of Change in Psychotherapy]

Mediators of Problematic Social Media Use in Adolescence as Possible Mechanisms of Change in Psychotherapy Social media are omnipresent in the lives of adolescents. Problematic use of social media has been linked to adverse mental health outcomes including depression, anxiety, suicidality, self-harm, body dissatisfaction and eating pathology. Preliminary evidence suggests that interventions aiming at reducing the amount of time spent in social media and changing dysfunctional beliefs about social media use are promising. However, the mechanisms of change of these interventions with regard to mental health remain unclear. Therefore, this review first provides an overview of the association between social media and mental health and then identifies mediators of this relationship as potential mechanisms of change of interventions targeting problematic media use in adolescents. The identified mediators encompass social comparison, decreased self-esteem, fear of missing out, sleep problems and increased rumination. Future studies should apply a longitudinal design, should investigate additional confounding variables (e. g. age, level of psychopathology) and should also focus on positive effects of social media use on mental health. Thereby, this line of research has the potential to improve our understanding how social media use exerts its effects and based thereupon to develop new or optimize current interventions on problematic social media use to improve mental health in adolescents by targeting the identified mediators.

Smartphone Use and Sleep Quality in Chinese College Students: A Preliminary Study

BACKGROUND

Chinese college students are at high risk of sleep problems, and smartphone use is common among this population. However, the relationship between smartphone use characteristics and sleep problems in Chinese college students has been inadequately studied. In this preliminary study, we examined the association of poor sleep quality with smartphone use in a sample of Chinese college students from a health vocational college in Changsha, China.

METHODS

A total of 439 college students completed a self-report questionnaire containing the Pittsburgh Sleep Quality Index (PSQI) and questions regarding demographic information, psychosocial factors, physical health, smartphone use characteristics, and mobile phone addiction (MPA).

RESULTS

The results showed that the prevalence of poor sleep quality (PSQI > 7) in Chinese college students was 9.8%. In multiple logistic regression analysis, poor sleep quality was significantly associated with male gender (OR: 2.80, P: 0.022), not having good physical health (OR: 2.61, P: 0.020), headache (OR: 2.47, P: 0.014), more severe depressive symptoms (OR: 2.17, P: 0.049), > four years of smartphone use (OR: 3.38, P: 0.001), > five hours of daily smartphone use (OR: 2.19, P: 0.049), and more severe inability to control MPA craving (OR: 2.04, P: 0.040).

CONCLUSION

Our findings suggest that excessive smartphone use and MPA are associated with poor sleep quality in a sample of Chinese college students from a health vocational college. Because of the limited sample representativeness and cross-sectional design of this study, large-scale prospective representative studies are warranted to confirm these associations.

Wellness and sleep quality in Korean nursing students: A cross-sectional study

BACKGROUND

Nursing students often experience stress and related sleep disturbances in striving to meet their academic needs. Wellness is the optimal state of health required to perform their roles successfully.

AIM

This study aimed to examine the relationship between wellness and sleep quality among nursing students in South Korea.

METHODS

We conducted a descriptive and correlational study, using standardized tools assessing sleep quality and wellness. Participants were recruited through convenience sampling. We surveyed 237 nursing students from two Korean universities, who agreed to participate in this study and completed a self-reported questionnaire between June 2017 and March 2018. The online questionnaire collected data on general information about the participants, their wellness, and their sleep quality. Data were analyzed using descriptive statistics, Mann-Whitney U test, chi-square test and correlation analyses.

RESULTS

We found a significant difference in wellness between the good-quality and poor-quality sleep groups and a positive correlation between nursing students' wellness and sleep quality.

CONCLUSIONS

The findings suggest that improving sleep quality is important for enhancing wellness among nursing students. Therefore, academic efforts are needed to improve nursing students' sleep quality and maximize their overall wellness and positively impact patient care.

Does the iPad Night Shift mode reduce melatonin suppression?

The increased use of self-luminous displays, especially in the evening prior to bedtime, has been associated with melatonin suppression, delayed sleep and sleep curtailment. The present study set out to investigate whether the Night Shift application provided by Apple Inc. for use on its portable electronic devices is effective for reducing acute melatonin suppression, a well-established marker of circadian phase. Participants experienced four experimental conditions: a dim light control, a high circadian stimulus true positive intervention and two Night Shift interventions delivering low and high correlated colour temperature light from the devices. Melatonin suppression did not significantly differ between the two Night Shift interventions, which indicates that changing the spectral composition of self-luminous displays without changing their brightness settings may be insufficient for preventing impacts on melatonin suppression.

The effect of smartphone usage at bedtime on sleep quality among Saudi non- medical staff at King Saud University Medical City

Objective:

This study's main objectives are to examine the prevalence of smartphone usage at bedtime and its effect on sleep quality among Saudi non-medical staff working in King Saud University medical city in Riyadh, Saudi Arabia.

Methods:

This cross-sectional study was carried out over the period from January 2016 to July 2016 A sample of 435 Saudi adults aged 21 years and above working in King Saud University Medical City in Riyadh, Saudi Arabia participated in a self-reported Arabic questionnaire about bedtime usage of smartphone and sleep quality. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Data were analyzed using odds ratio.

Results:

More than 98% of the respondents owned a smartphone, and nine out of ten use their smartphones at bedtime. Social media was the most used service among participants. An increase in bedtime smartphone use specially more than 60 minutes makes participants at great risk of having poor sleep quality.

Conclusion:

our findings suggest that employees who use their smartphones more at bedtime have more risk of being poor sleepers. More attention should be drawn to the misuse of smartphones and its effect sleep quality, health and productivity of adults.

Eyeing computer vision syndrome: Awareness, knowledge, and its impact on sleep quality among medical students

BACKGROUND

Computer vision syndrome (CVS) encompasses a constellation of ocular and extraocular symptoms in computer users who either habitually or compulsively use computers for long periods of time. Electronic devices such as computers, smart phones, and tablets emit blue light (400-490 nm) from their light-emitting diodes and produce electromagnetic fields, both of which interfere with the circadian rhythm.

AIM

This study aims to assess the awareness, knowledge, and impact on sleep quality of CVS among medical students.

MATERIALS AND METHODS

This study included 500 medical students. All participants anonymously filled up a pro forma including sociodemographic details and three questionnaires that (a) tested for awareness and knowledge about CVS, (b) tested for CVS, and (c) the Pittsburgh sleep quality index (PSQI), respectively. Data from 463 complete questionnaires were analyzed.

RESULTS

The mean (±standard deviation) age of the 463 individuals was 19.55 (±1.04) years. The prevalence of CVS was 77.5%. The prevalence was higher in boys (80.23%) compared to girls (75.87%), but the difference was not statistically significant. Only 34.1% of the medical students were aware of CVS. Good knowledge regarding various aspects of CVS was observed in 22.46% individuals, while 53.99% and 23.56% had average and poor knowledge, respectively. Poor sleep quality was present in 75.49% of individuals with CVS compared to 50.96% of students without CVS; the difference was statistically significant (odd's ratio [95% confidence interval]: 0.338 [0.214-0.531]). All the components of PSQI score, except components 1 and 6, had statistically significantly (P < 0.05) higher values in individuals with CVS as compared to individuals without CVS.

CONCLUSIONS

There is high prevalence but low level of awareness and knowledge about CVS among medical students. CVS is significantly associated with poor sleep quality in medical students.

Overnight smartphone use: A new public health challenge? A novel study design based on high-resolution smartphone data

Background

Round-the-clock use of smartphones holds a potential for awakenings and/or shorter sleep duration, which may have adverse health consequences. We aim to describe overnight smartphone activity among young adults and to characterize those with smartphone interrupted sleep in terms of sleep impairment and mental and physical health indicators.

Methods

We use unique objective high-resolution information on timing of smartphone activity (based on >250,000 phone actions) continuously monitored over a four-week period among 815 young adults combined with indicators of mental and physical health.

Results

We find substantial overnight smartphone activity. More than 12% had smartphone activity in the middle of the night (3 to 5 hours after self-reported bedtime) and 41% had smartphone interrupted sleep on at least one weekday during a 4-week period. Those with frequent smartphone interrupted sleep had on average 48 minutes shorter self-reported sleep duration and higher body mass index, whereas there were no differences in physical or mental health symptoms.

Conclusions

The substantial smartphone activity during bed hours among young adults may pose a public health challenge and especially the relation to overweight warrants close attention.

Diplomats' Mystery Illness and Pulsed Radiofrequency/Microwave Radiation

Importance: A mystery illness striking U.S. and Canadian diplomats to Cuba (and now China) "has confounded the FBI, the State Department and US intelligence agencies" (Lederman, Weissenstein, & Lee, 2017). Sonic explanations for the so-called health attacks have long dominated media reports, propelled by peculiar sounds heard and auditory symptoms experienced. Sonic mediation was justly rejected by experts. We assessed whether pulsed radiofrequency/microwave radiation (RF/MW) exposure can accommodate reported facts in diplomats, including unusual ones. Observations: (1) Noises: Many diplomats heard chirping, ringing or grinding noises at night during episodes reportedly triggering health problems. Some reported that noises were localized with laser-like precision or said the sounds seemed to follow them (within the territory in which they were perceived). Pulsed RF/MW engenders just these apparent "sounds" via the Frey effect. Perceived "sounds" differ by head dimensions and pulse characteristics and can be perceived as located behind in or above the head. Ability to hear the "sounds" depends on high-frequency hearing and low ambient noise. (2) Signs/symptoms: Hearing loss and tinnitus are prominent in affected diplomats and in RF/MW-affected individuals. Each of the protean symptoms that diplomats report also affect persons reporting symptoms from RF/MW: sleep problems, headaches, and cognitive problems dominate in both groups. Sensations of pressure or vibration figure in each. Both encompass vision, balance, and speech problems and nosebleeds. Brain injury and brain swelling are reported in both. (3) Mechanisms: Oxidative stress provides a documented mechanism of RF/MW injury compatible with reported signs and symptoms; sequelae of endothelial dysfunction (yielding blood flow compromise), membrane damage, blood-brain barrier disruption, mitochondrial injury, apoptosis, and autoimmune triggering afford downstream mechanisms, of varying persistence, that merit investigation. (4) Of note, microwaving of the U.S. embassy in Moscow is historically documented. Conclusions and relevance: Reported facts appear consistent with pulsed RF/MW as the source of injury in affected diplomats. Nondiplomats citing symptoms from RF/MW, often with an inciting pulsed-RF/MW exposure, report compatible health conditions. Under the RF/MW hypothesis, lessons learned for diplomats and for RF/MW-affected civilians may each aid the other.

Adolescent Sleep Barriers: Profiles within a Diverse Sample of Urban Youth

Most adolescents face numerous obstacles to good sleep, which may undermine healthy development. In this study, we used latent class analysis and identified four categories of sleep barriers in a diverse sample of 553 urban youth (57% female). The majority profile, School/Screens Barriers, reported the most homework and extracurricular barriers, along with high screen time. The Home/Screens Barriers class (i.e., high environmental noise, light, screen use) and the High/Social Barriers class (i.e., high barriers across domains, particularly social) reported the poorest sleep quality and highest depressive/anxiety symptoms. The Minimal Barriers class-predominately male, with low depressive/anxiety symptoms-reported more sleep per night. We discuss implications of our findings for targeting interventions to address poor adolescent sleep among specific clusters of students.

Lessons and Perspectives from a 25-Year Bioelectromagnetics Research Program

The question of whether electromagnetic fields from electric power or telecommunications systems can be linked unequivocally to health detriments has occupied scientific research endeavors for nearly half a century. For 25 years, the bioelectromagnetic research group at Swinburne University in Melbourne, Australia, has pursued a series of investigations with relevant endpoints, such as neurophysiological and neuropsychological effects, cell calcium level changes, proliferation, and genotoxic effects. Most have shown no significant changes due to fields, however, in some pilot studies significant changes were revealed, but in most cases these were not replicated in follow-up studies. This highlights a feature of this research area, generally; the unambiguous identification of small changes in noisy data where the understanding of possible interaction mechanisms is lacking. On the other hand, mathematical modelling studies, particularly with respect to fields near metallic implants, in workers exposed to fields in harsh environmental conditions and at very high frequencies (THz), continue to add to the expanding knowledge database on the characteristics of the complex electromagnetic environment we live in today.

Microwaves and Alzheimer's disease

Alzheimer's diseases (AD) is the most common type of dementia and a neurodegenerative disease that occurs when the nerve cells in the brain die. The cause and treatment of AD remain unknown. However, AD is a disease that affects the brain, an organ that controls behavior. Accordingly, anything that can interact with the brain may affect this organ positively or negatively, thereby protecting or encouraging AD. In this regard, modern life encompasses microwaves for all issues including industrial, communications, medical and domestic tenders, and among all applications, the cell phone wave, which directly exposes the brain, continues to be the most used. Evidence suggests that microwaves may produce various biological effects on the central nervous system (CNS) and many arguments relay the possibility that microwaves may be involved in the pathophysiology of CNS disease, including AD. By contrast, previous studies have reported some beneficial cognitive effects and that microwaves may protect against cognitive impairment in AD. However, although many of the beneficial effects of microwaves are derived from animal models, but can easily be extrapolated to humans, whether microwaves cause AD is an important issue that is to be addressed in the current review.

The Role of Environmental Factors on Sleep Patterns and School Performance in Adolescents

Background: Modern life, with its many distractions, is seeing sleep quantity and quality decline during adolescence. This is a concern as research persuasively demonstrates the negative impact of reduced sleep on academic achievement, both in terms of learning and behavior.

Aims: This study examined the relationship between sleep and school functioning in adolescence, with a focus on environmental factors that might mediate this relationship.

Sample and Method: Forty-seven adolescents took part. Sleep was measured using the School Sleep Habits Survey (SSHS) and a sleep diary. School records of year grade point averages provided a measure of academic achievement. Raven's Standard Progressive Matrices gave a measure of general cognitive processing. Environmental sleep factors falling into three groups, namely, stimulant consumption, media use and exercise, were measured using a self-report questionnaire.

Results: An average of 7.08 h of sleep was reported. Correlations revealed that Total sleep time (TST) and bedtimes on weekdays were strongly associated with academic achievement. Morning/eveningness and sleep/wake behavior problems had a strong relationship with performance on the Ravens. Stimulant consumption and media use before bed revealed strong relationships with TST and bedtimes on weekdays. Crucially, mediation analyses confirmed that both caffeine consumption and electronic media use before bedtime were negatively associated with academic performance, via the mediating pathway by affecting sleep. Exercise was not associated with any of the sleep variables, but was associated with better academic performance.

Conclusion: The current findings highlight that, now more than ever, parents, schools and policy makers must be aware of the negative effects of caffeinated substances marketed to students, and electronic media use on their sleep habits. Our findings suggest that targeting caffeine consumption and electronic media use before bed may represent effective routes in alleviating modern teenage sleep debt, and in turn enhancing academic performance.

Relationship of smartphone use severity with sleep quality, depression, and anxiety in university students

BACKGROUND AND AIMS

The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students.

METHODS

In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh Sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale.

RESULTS

The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and daytime dysfunction scores were higher in the high smartphone use group than in the low smartphone use group. Positive correlations were found between the Smartphone Addiction Scale scores and depression levels, anxiety levels, and some sleep quality scores.

CONCLUSIONS

The results indicate that depression, anxiety, and sleep quality may be associated with smartphone overuse. Such overuse may lead to depression and/or anxiety, which can in turn result in sleep problems. University students with high depression and anxiety scores should be carefully monitored for smartphone addiction.

Circadian rhythmicity of antioxidant markers in rats exposed to 1.8 GHz radiofrequency fields

Background: The potential health risks of exposure to Radiofrequency Fields (RF) emitted by mobile phones are currently of considerable public interest, such as the adverse effects on the circadian rhythmicities of biological systems. To determine whether circadian rhythms of the plasma antioxidants (Mel, GSH-Px and SOD) are affected by RF, we performed a study on male Sprague Dawley rats exposed to the 1.8 GHz RF. Methods: All animals were divided into seven groups. The animals in six groups were exposed to 1.8 GHz RF (201.7 μW/cm² power density, 0.05653 W/kg specific absorption rate) at a specific period of the day (3, 7, 11, 15, 19 and 23 h GMT, respectively), for 2 h/day for 32 consecutive days. The rats in the seventh group were used as sham-exposed controls. At the end of last RF exposure, blood samples were collected from each rat every 4 h (total period of 24 h) and also at similar times from sham-exposed animals. The concentrations of three antioxidants (Mel, GSH-Px and SOD) were determined. The data in RF-exposed rats were compared with those in sham-exposed animals. Results: circadian rhythms in the synthesis of Mel and antioxidant enzymes, GSH-Px and SOD, were shifted in RF-exposed rats compared to sham-exposed animals: the Mel, GSH-Px and SOD levels were significantly decreased when RF exposure was given at 23 and 3 h GMT. Conclusion: The overall results indicate that there may be adverse effects of RF exposure on antioxidant function, in terms of both the daily antioxidative levels, as well as the circadian rhythmicity.

Radiofrequency exposure in young and old: different sensitivities in light of age-relevant natural differences

Our environment is now permeated by anthropogenic radiofrequency electromagnetic radiation, and individuals of all ages are exposed for most of each 24 h period from transmitting devices. Despite claims that children are more likely to be vulnerable than healthy adults to unwanted effects of this exposure, there has been no recent examination of this, nor of comparative risk to the elderly or ill. We sought to clarify whether research supports the claim of increased risk in specific age-groups. First, we identified the literature which has explored age-specific pathophysiological impacts of RF-EMR. Natural life-span changes relevant to these different impacts provides context for our review of the selected literature, followed by discussion of health and well-being implications. We conclude that age-dependent RF-EMR study results, when considered in the context of developmental stage, indicate increased specific vulnerabilities in the young (fetus to adolescent), the elderly, and those with cancer. There appears to be at least one mechanism other than the known thermal mechanism causing different responses to RF-EMR depending upon the exposure parameters, the cell/physiological process involved, and according to age and health status. As well as personal health and quality-of-life impacts, an ageing population means there are economic implications for public health and policy.

Adolescents' electronic media use at night, sleep disturbance, and depressive symptoms in the smartphone age

Adolescence is a time of increasing vulnerability for poor mental health, including depression. Sleep disturbance is an important risk factor for the development of depression during adolescence. Excessive electronic media use at night is a risk factor for both adolescents' sleep disturbance and depression. To better understand the interplay between sleep, depressive symptoms, and electronic media use at night, this study examined changes in adolescents' electronic media use at night and sleep associated with smartphone ownership. Also examined was whether sleep disturbance mediated the relationship between electronic media use at night and depressive symptoms. 362 adolescents (12-17 year olds, M = 14.8, SD = 1.3; 44.8% female) were included and completed questionnaires assessing sleep disturbance (short sleep duration and sleep difficulties) and depressive symptoms. Further, participants reported on their electronic media use in bed before sleep such as frequency of watching TV or movies, playing video games, talking or text messaging on the mobile phone, and spending time online. Smartphone ownership was related to more electronic media use in bed before sleep, particularly calling/sending messages and spending time online compared to adolescents with a conventional mobile phone. Smartphone ownership was also related to later bedtimes while it was unrelated to sleep disturbance and symptoms of depression. Sleep disturbance partially mediated the relationship between electronic media use in bed before sleep and symptoms of depression. Electronic media use was negatively related with sleep duration and positively with sleep difficulties, which in turn were related to depressive symptoms. Sleep difficulties were the more important mediator than sleep duration. The results of this study suggest that adolescents might benefit from education regarding sleep hygiene and the risks of electronic media use at night.

The sleep and technology use of Americans: findings from the National Sleep Foundation's 2011 Sleep in America poll

STUDY OBJECTIVES

To describe the technology use and sleep quality of Americans, and the unique association between technology use and sleep disturbances.

METHODS

Interviews were conducted via random digit dialing (N = 750) or the Internet (N = 758). 1,508 Americans (13-64 years old, 50% males) matched to 2009 U.S. Census data provided complete interviews. The sample was further divided into adolescents (13-18 years, N = 171), young adults (19-29 years, N = 293), middle-aged adults (30-45 years, N = 469), and older adults (46-64 years, N = 565) to contrast different generations' technology use. Participants answered a 47-item semi-structured survey, including questions about their sleep habits, and the presence and use of technology in the hour before bed in the past 2 weeks.

RESULTS

Nine of 10 Americans reported using a technological device in the hour before bed (e.g., TVs the most popular; 60%). However, those under 30 years of age were more likely to use cell phones (72% of adolescents, 67% of young adults) than those over 30 years (36% of middle-aged, and 16% of older adults). Young adults' sleep patterns were significantly later than other age groups on both weekdays and weekend nights. Unlike passive technological devices (e.g., TV, mp3 music players), the more interactive technological devices (i.e., computers/laptops, cell phones, video game consoles) used in the hour before bed, the more likely difficulties falling asleep (β = 9.4, p < 0.0001) and unrefreshing sleep (β = 6.4, p < 0.04) were reported.

CONCLUSIONS

Technology use near bedtime is extremely prevalent in the United States. Among a range of technologies, interactive technological devices are most strongly associated with sleep complaints.

Pineal melatonin level disruption in humans due to electromagnetic fields and ICNIRP limits

The International Agency for Research on Cancer (IARC) classifies electromagnetic fields (EMFs) as 'possibly carcinogenic' to humans that might transform normal cells into cancer cells. Owing to high utilisation of electricity in day-to-day life, exposure to power-frequency (50 or 60 Hz) EMFs is unavoidable. Melatonin is a natural hormone produced by pineal gland activity in the brain that regulates the body's sleep-wake cycle. How man-made EMFs may influence the pineal gland is still unsolved. The pineal gland is likely to sense EMFs as light but, as a consequence, may decrease the melatonin production. In this study, more than one hundred experimental data of human and animal studies of changes in melatonin levels due to power-frequency electric and magnetic fields exposure were analysed. Then, the results of this study were compared with the International Committee of Non-Ionizing Radiation Protection (ICNIRP) limit and also with the existing experimental results in the literature for the biological effect of magnetic fields, in order to quantify the effects. The results show that this comparison does not seem to be consistent despite the fact that it offers an advantage of drawing attention to the importance of the exposure limits to weak EMFs. In addition to those inconsistent results, the following were also observedfrom this work: (i) the ICNIRP recommendations are meant for the well-known acute effects, because effects of the exposure duration cannot be considered and (ii) the significance of not replicating the existing experimental studies is another limitation in the power-frequency EMFs. Regardless of these issues, the above observation agrees with our earlier study in which it was confirmed that it is not a reliable method to characterise biological effects by observing only the ratio of AC magnetic field strength to frequency. This is because exposure duration does not include the ICNIRP limit. Furthermore, the results show the significance of disruption of melatonin due to exposure to weak EMFs, which may possibly lead to long-term health effects in humans.

The association between use of mobile phones after lights out and sleep disturbances among Japanese adolescents: a nationwide cross-sectional survey

STUDY OBJECTIVE

The objective of this study was to examine the association between the use of mobile phones after lights out and sleep disturbances among Japanese adolescents.

DESIGN AND SETTING

This study was designed as a cross-sectional survey. The targets were students attending junior and senior high schools throughout Japan. Sample schools were selected by cluster sampling. Self-reported anonymous questionnaires were sent to schools for all students to fill out.

PARTICIPANTS

A total of 95,680 adolescents responded. The overall response rate was 62.9%, and 94,777 questionnaires were subjected to analysis.

INTERVENTION

N/A.

MEASUREMENTS AND RESULTS

Daily mobile phone use, even if only for a brief moment every day, was reported by 84.4%. Moreover, as for use of mobile phones after lights out, 8.3% reported using their mobile phone for calling every day and 17.6% reported using it for sending text messages every day. Multiple logistic regression analysis showed that mobile phone use for calling and for sending text messages after lights out was associated with sleep disturbances (short sleep duration, subjective poor sleep quality, excessive daytime sleepiness, and insomnia symptoms) independent of covariates and independent of each other.

CONCLUSION

This study showed that the use of mobile phones for calling and for sending text messages after lights out is associated with sleep disturbances among Japanese adolescents. However, there were some limitations, such as small effect sizes, in this study. More studies that examine the details of this association are necessary to establish strategies for sleep hygiene in the future.

Electronic media use and sleep in school-aged children and adolescents: A review

Electronic media have often been considered to have a negative impact on the sleep of children and adolescents, but there are no comprehensive reviews of research in this area. The present study identified 36 papers that have investigated the relationship between sleep and electronic media in school-aged children and adolescents, including television viewing, use of computers, electronic gaming, and/or the internet, mobile telephones, and music. Many variables have been investigated across these studies, although delayed bedtime and shorter total sleep time have been found to be most consistently related to media use. A model of the mechanisms by which media use may affect sleep is presented and discussed as a vehicle for future research.

Recent advances in research on radiofrequency fields and health: 2004-2007

The widespread use of wireless telecommunications devices, particularly mobile phones and wireless networks, has resulted in increased human exposure to radiofrequency (RF) fields. Although national and international agencies have established safety guidelines for exposure to RF fields, concerns remain about the potential for adverse health outcomes to occur in relation to RF field exposure. The extensive literature on RF fields and health was reviewed by a number of authorities, including the Royal Society of Canada (1999). This report is the third in a series of updates to the original report of the Royal Society of Canada, covering the period 2004-2007. In particular, the present study examined new data on (1) dosimetry and exposure assessment, (2) biological effects of RF fields such as enzyme induction, and (3) toxicological effects, including genotoxicity and carcinogenicity. Epidemiological studies of the potential health effects of RF exposure, particularly from mobile phones, were determined, along with human and animal studies of neurological and behavioural effects. Within the last 4 yrs investigators concluded that there is no clear evidence of adverse health effects associated with RF fields, although continued research is recommended to address specific areas of concern, including exposure to RF fields among children using mobile phones. The results of the ongoing 13-country World Health Organization INTERPHONE study of mobile phones may provide important new information on the potential cancer risks associated with mobile phone use.

Effects of low-level radio-frequency (3kHz to 300GHz) energy on human cardiovascular, reproductive, immune, and other systems: A review of the recent literature

OBJECTIVES

Occupational or residential exposures to radio-frequency energy (RFE), including microwaves, have been alleged to result in health problems. A review of recent epidemiological studies and studies of humans as subjects in laboratory investigations would be useful.

METHODS

This paper is a narrative review of the recent medical and scientific literature (from mid-1998 through early 2006) dealing with possible effects of RFE on humans, relating to topics other than cancer, tumors, and central nervous system effects (areas covered in a previous review). Subject areas in this review include effects on cardiovascular, reproductive, and immune systems.

RESULTS

A large number of studies were related to exposures from cellular telephones. Although both positive and negative findings were reported in some studies, in a majority of instances no significant health effects were found. Most studies had some methodological limitations. Although some cardiovascular effects due to RFE were reported in epidemiological studies (e.g., lower 24-h heart rate, blunted circadian rhythm of heart rate), there were no major effects on a large number of cardiovascular parameters in laboratory studies of volunteers during exposure to cell-phone RFE. In population-based studies of a wide range of RFE frequencies, findings were equivocal for effects on birth defects, fertility, neuroblastoma in offspring, and reproductive hormones. Some changes in immunoglobulin levels and in peripheral blood lymphocytes were reported in different studies of radar and radio/television-transmission workers. Due to variations in results and difficulties in comparing presumably exposed subjects with controls, however, it is difficult to propose a unifying hypothesis of immune-system effects. Although subjective symptoms may be produced in some sensitive individuals exposed to RFE, there were no straightforward differences in such symptoms between exposed and control subjects in most epidemiological and laboratory studies. Consistent, strong associations were not found for RFE exposure and adverse health effects. The majority of changes relating to each of the diseases or conditions were small and not significant.

CONCLUSIONS

On the basis of previous reviews of older literature and the current review of recent literature, there is only weak evidence for a relationship between RFE and any endpoint studied (related to the topics above), thus providing at present no sufficient foundation for establishing RFE as a health hazard.

Adolescent use of mobile phones for calling and for sending text messages after lights out: results from a prospective cohort study with a one-year follow-up

OBJECTIVE

To assess the prevalence of the use of mobile phones by adolescents after lights out and its relationship to tiredness levels after one year.

DESIGN

Prospective cohort study with self-reports and follow up questionnaire after one year.

SETTING

Second- and fifth-year secondary school children in 15 schools in Flanders, Belgium.

PARTICIPANTS

1656 school children; 52.1% boys. Average age was 13.7 years (SD: 0.68) in the youngest group and 16.9 years (SD: 0.83) in the oldest group at baseline.

MAIN OUTCOME MEASURES

Self-reported tiredness.

RESULTS

Only 38% of the subjects never used their mobile phone after lights out. Multinomial logistic regression showed that using the mobile phone less than once a month increased the odds of being very tired one year later by 1.8 (95% CI 1.2-2.8). Those who used it less than once a week were 2.2 times more likely to be very tired (95% CI 1.4-3.5). Using it about once a week increased the odds by 3.3 (95% CI 1.9-5.7) and those who used it more than once a week were 5.1 times more likely to be very tired (95% CI 2.5-10.4). Overall 35% of the cases of being very tired were attributed to the use of the mobile phone. Use of the phone right after lights out increased the odds of being very tired by 2.2 (95% CI 1.4-3.4); between 00:00 and 03:00 the odds were 3.9 times higher (95% CI 2.1-7.1), and in those who used it at any time of the night the odds were 3.3 times higher (95% CI 1.8-6.0).

CONCLUSION

Mobile phone use after lights out is very prevalent among adolescents. Its use is related to increased levels of tiredness. There is no safe dose and no safe time for using the mobile phone for text messaging or for calling after lights out.