Effects of radiofrequency electromagnetic field exposure on sleep quality

The use of wireless communication devices, which emit radiofrequency electromagnetic fields (RF-EMF), has increased in the past decades. According to the World Health Organization (WHO) mobile phone use is ubiquitous with an estimated 4.6 billion subscriptions globally. The missing knowledge about a biological mechanism and the attribution of non-specific symptoms of ill health to RF-EMF has led to an increased public concern about possible adverse health effects from this radiation. One of the most often reported symptoms due to RF-EMF exposure are sleep disturbances. In several randomised double-blind human laboratory studies, changes in the sleep electroencephalogram (EEG) after exposure to RF-EMF were observed. The impact of these small changes on sleep quality and therefore on general well-being is unclear. Previous epidemiological studies have used a cross-sectional design, which is not appropriate for establishing causal relationships between exposure and outcome. Studies with a cohort design are therefore needed. Additionally, exposure assessment was mostly inadequate or only parts of the real exposure situation were taken into account. Personal measurement devices (exposimeters) have become available a few years age. In large epidemiological studies, it is very time-consuming and costly to use such devices. Other exposure assessment methods are therefore needed. The main aim of this thesis was to investigate the association between personal RF-EMF exposure and sleep quality by using objective as well as subjective data. To predict personal exposure to RF-EMF a comprehensive exposure assessment method was applied. This thesis was part of the QUALIFEX project (a prospective cohort study on radiofrequency electromagnetic field exposure and health related quality of life) which is embedded in the National Research Program 57 (NRP-57) about non-ionising radiation. The health effect of RF-EMF exposure was investigated in a cohort study which consisted of a baseline survey in May 2008 and a follow-up survey one year later. Questionnaires entitled „Environment and Health“ were sent out to 1375 randomly selected study participants in the region of Basel (Switzerland). Information on sleep quality, on exposure relevant factors and on various confounding factors was collected. By means of a pre-study, which was not part of this thesis, a comprehensive exposure assessment method was developed. To predict personal exposure to far-field RF-EMF (e.g mobile phone base stations or radio transmitters), a validated full exposure prediction model was used which was developed based personal exposure measurements of 166 study participants who took part in a pre-study. Exposure to close to body sources was assessed using self-reported data on mobile phone and cordless phone use. Objective data of mobile phone use from network operators for participants who gave informed consent were additionally collected. For a nested sleep study, 120 participants out of the baseline survey took part in a nested sleep study to verify our previous results. Sleep quality and sleep behavior was assessed using actigraphy and exposure to RF-EMF was measured by means of personal exposimeters. For the baseline survey, mean calculated RF-EMF exposure to all relevant sources of all 1375 study participants was 0.12 mW/m2 (0.21 V/m). Exposure at the follow-up survey was 0.13 mW/m2 (0.22 V/m) and therefore comparable with the baseline exposure. No consistent association between RF-EMF exposure and self-reported sleep quality neither in the baseline analysis (cross-sectional analysis) nor in the cohort analysis (longitudinal analysis) was observed. In the nested sleep study, objective data on exposure and sleep quality did not yield any association between exposure and sleep quality. The QUALIFEX project was the first study which applied a cohort design to investigate the association between RF-EMF exposure and sleep quality. Additionally, we were able to verify our results of the cohort study with objective data obtained in a nested sleep study. Overall, we found no consistent association between self-reported as well as objectively measured sleep quality and exposure to relevant RF-EMF sources in everyday life. Our results increase the evidence for a true absence of an effect of RF-EMF exposure on sleep quality. Our study used a very comprehensive exposure assessment method which included far-field sources as well as close to body sources. In general, exposure levels were very small and changes between the baseline and the follow-up survey were marginal. Hence, with our study no conclusions can be drawn regarding potential health effects of higher exposure levels. In future studies, more data on long-term effects have to be collected. Additionally, the exposure situation in everyday life should be monitored because new technologies operating with RF-EMF are continuously arising

Exposure to Radiofrequency Electromagnetic Fields and Sleep Quality: A Prospective Cohort Study

BACKGROUND: There is persistent public concern about sleep disturbances due to radiofrequency electromagnetic field (RF-EMF) exposure. The aim of this prospective cohort study was to investigate whether sleep quality is affected by mobile phone use or by other RF-EMF sources in the everyday environment. METHODS: We conducted a prospective cohort study with 955 study participants aged between 30 and 60 years. Sleep quality and daytime sleepiness was assessed by means of standardized questionnaires in May 2008 (baseline) and May 2009 (follow-up). We also asked about mobile and cordless phone use and asked study participants for consent to obtain their mobile phone connection data from the mobile phone operators. Exposure to environmental RF-EMF was computed for each study participant using a previously developed and validated prediction model. In a nested sample of 119 study participants, RF-EMF exposure was measured in the bedroom and data on sleep behavior was collected by means of actigraphy during two weeks. Data were analyzed using multivariable regression models adjusted for relevant confounders. RESULTS: In the longitudinal analyses neither operator-recorded nor self-reported mobile phone use was associated with sleep disturbances or daytime sleepiness. Also, exposure to environmental RF-EMF did not affect self-reported sleep quality. The results from the longitudinal analyses were confirmed in the nested sleep study with objectively recorded exposure and measured sleep behavior data. CONCLUSIONS: We did not find evidence for adverse effects on sleep quality from RF-EMF exposure in our everyday environmen

Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

Background: The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods: The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results: We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion: Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas

Effect of nocturnal road traffic noise exposure and annoyance on objective and subjective sleep quality

Various epidemiological studies have found an association between noise exposure and sleep quality, but the mediating role of annoyance is unclear for this association.; To investigate the effects of both objectively modeled road traffic noise exposure as well as noise annoyance on subjective and objective sleep quality measures.; 1375 randomly selected participants from Basel, Switzerland, were enrolled in a questionnaire survey in 2008 with follow-up one year later (1122 participants). We assessed sleep quality by using a standardized sleep disturbance score, as well as the level of annoyance with road traffic noise at home. Objective sleep efficiency data was collected in a nested diary study by means of actigraphy from 119 subjects for 1551 nights. Residential nocturnal exposure to road traffic noise was modeled using validated models. Data were analyzed with random intercept mixed-effects regression models.; In the main study, self-reported sleep quality was strongly related to noise annoyance (p for trend>0.001) but only moderately correlated with modeled noise exposure (p=0.07). In the nested diary study objectively measured sleep efficiency was not related to annoyance (p=0.25) but correlated with modeled noise exposure (p=0.02). Strikingly, noise induced decreased sleep efficiency was even more significant for study participants who were not annoyed with traffic noise (p=0.001).; This study indicates that effects of nocturnal traffic noise on objective sleep quality are independent of perceived noise annoyance, whereas the association between self-reported sleep quality and noise is mediated by noise annoyance

Systematic review on the health effects of exposure to radiofrequency electromagnetic fields from mobile phone base stations

OBJECTIVE: To review and evaluate the recent literature on the health effects of exposure to mobile phone base station (MPBS) radiation. METHODS: We performed a systematic review of randomized human trials conducted in laboratory settings and of epidemiological studies that investigated the health effects of MPBS radiation in the everyday environment. FINDINGS: We included in the analysis 17 articles that met our basic quality criteria: 5 randomized human laboratory trials and 12 epidemiological studies. The majority of the papers (14) examined self-reported non-specific symptoms of ill-health. Most of the randomized trials did not detect any association between MPBS radiation and the development of acute symptoms during or shortly after exposure. The sporadically observed associations did not show a consistent pattern with regard to symptoms or types of exposure. We also found that the more sophisticated the exposure assessment, the less likely it was that an effect would be reported. Studies on health effects other than non-specific symptoms and studies on MPBS exposure in children were scarce. CONCLUSION: The evidence for a missing relationship between MPBS exposure up to 10 volts per metre and acute symptom development can be considered strong because it is based on randomized, blinded human laboratory trials. At present, there is insufficient data to draw firm conclusions about health effects from long-term low-level exposure typically occurring in the everyday environmen

Noise-related sleep disturbances : does gender matter?

Women sleep differently and report differently about sleep disturbances than men. However, it is unclear whether the sleep of women and men is affected differently by traffic noise exposure. We aimed to address gender specific noise effects by using objective and subjective exposure measures as well as objective and subjective outcome data. In a questionnaire survey conducted in 2008 including 733 women and 533 men from Basel, Switzerland, with follow-up 1 year later, we collected data on subjective sleep disturbances and annoyance to road traffic noise. Objective noise exposure data was obtained using validated propagation models. In a nested diary study with 119 participants, objective sleep efficiency and sleep duration was measured by means of actigraphic devices for 1551 nights. Data were analyzed using random intercept mixed-effects multilevel regression models adjusted for relevant confounding factors. Objectively measured sleep duration in highly exposed men (30 dB). No noise effect on sleep duration was observed in women. The association of modeled noise exposure with self-reported sleep quality rating was also more pronounced in men (-0.8 unit, 95% CI: -1.4 to -0.2) than in women (-0.3 unit, 95% CI: -0.8 to 0.2). However, in highly annoyed women reduction in sleep quality and well-being rating tended to be stronger than in highly annoyed men. Our study provides some indications that noise exposure affects men's sleep differently than women's sleep, which may have distinct long-term health consequences