Symptom reporting after the introduction of a new high-voltage power line: a prospective field study

Should Parents Allow Their Children Use Smartphones and Tablets? The Issue of Screen Time for Recreational Activities

Previous research has shown that children are more vulnerable to the adverse effects of radiofrequency electromagnetic fields (RF-EMFs) and blue light emitted from digital screens compared to healthy adults. This paper presents the findings of a cross-sectional study conducted in Yasuj, Iran, to investigate the screen time habits of children and adolescents and its potential impact on their health. A total of 63 participants, including 44 boys and 19 girls, were randomly selected for the study. The results showed that the average daily screen time for the children was 87.38 minutes, with a standard deviation of 49.58. When examining the specific purposes of screen time, it was found that the children spent an average of 17.54 minutes per day on screens for school assignments, 70 minutes per day for recreational purposes, and 23.41 minutes per day for contacting family, friends, and relatives. Our study highlights that a significant portion of the children's screen time was allocated to recreational activities. We observed some differences in screen time between girls and boys. Boys had a slightly higher overall daily screen time, primarily driven by more recreational screen time. However, girls spent slightly more time on screens for school assignments. The screen time for social interactions was similar for both genders. Our findings on the cognitive performance of children with different levels of screen time will be published in a separate paper.

On the Power Lines—Electromagnetic Shielding Using Magnetic Steel Laminates

Protection against the electromagnetic fields around high-voltage transmission lines is an issue of great importance, especially in the case of buildings near power lines. Indeed, the developed fields can be harmful for the habitants and electrical/electronic devices, so the implementation of appropriate measures to address the above electromagnetic interference issue is necessary in order to ensure the safety of both human beings and equipment. Several practices have been proposed to reduce the electric and the magnetic fields around overhead and underground transmission lines (minimum distance, shielded cables, anechoic chamber etc.). In this context, the scope of the current paper is the use of highly permeable magnetic sheets for shielding purposes, along with the development of an appropriate procedure, based on finite element analysis (FEA) for the efficient design of passive shielding. The simulation results are compared with laboratory measurements in order to confirm the adequacy of the proposed methodology. The good agreement between the FEA outcomes and the experimental results confirms that the developed FEA tool can be trustfully used for the design of the shielding means in the case of overhead or underground power lines.

Attitude toward livestock farming does not influence the earlier observed association between proximity to goat farms and self-reported pneumonia

Attitudes toward environmental risks may be a source of bias in environmental health studies because concerns about environmental hazards may influence self-reported outcomes.

OBJECTIVE

The main aim was to assess whether earlier observed associations between proximity to goat farms and self-reported pneumonia were biased by participants' attitude toward farming.

METHODS

We developed an attitude-score for 2,457 participants of the Dutch Livestock Farming and Neighbouring Residents' Health Study (veehouderij en gezondheid omwonenden) by factor analysis of 13 questionnaire items related to attitude toward livestock farming. Linear regression analysis was used to assess associations between attitude and potential determinants. The effect of attitude on the association between goat farm proximity and pneumonia was analyzed by evaluating (1) misclassification of the outcome, (2) effect modification by attitude, and (3) exclusion of participants reporting health problems due to farms in their environment.

RESULTS

In general, the study population had a positive attitude toward farming, especially if participants were more familiar with farming. Older participants, females, ex-smokers, and higher-educated individuals had a more negative attitude. Both self-reported respiratory symptoms and exposure to livestock farms were associated with a more negative attitude. Misclassification of self-reported pneumonia was nondifferential with regard to participants' attitude. Furthermore, no indication was found that the association between proximity to goat farms and pneumonia was modified by attitude. Excluding subjects who attributed their health symptoms to livestock farms did also not change the association.

CONCLUSIONS

The association between goat farm proximity and pneumonia was not substantially biased by study participants' attitude toward livestock farming.

Evaluation of the electromagnetic field intensity in operating rooms and estimation of occupational exposures of personnel

Introduction

Operating rooms in hospitals are facilitated with different types of electronic systems, which produce electromagnetic waves. High intensities of magnetic waves may have harmful effects on biological environments. This study aims to evaluate the electromagnetic field intensity at different parts of operating rooms at the first stage and estimate the occupational exposure to operating room personnel at the next phase.

Materials and methods

At this cross-sectional study, the magnetic field intensity was evaluated using teslameter at several parts of operating rooms, during operating procedures, while electrical instruments were working. Background electromagnetic field intensity was measured when all the electrical systems were idle. Statistical analysis was performed using SPSS software. The results were compared with ICNIRP standards.

Results

The maximum intensity of magnetic field was measured around high-voltage systems at the distance of 50 cm in the personnel’s standing area at DCR and PCNL operating procedures were 5.9 and 5.6, respectively. The number of on-mode electrical systems was inconsistent with the intensity of electromagnetic fields at the standing area of operating room personnel’s. The intensity of magnetic fields around high-voltage systems, which was about 46.75 mG at the distance of 10 cm, was the highest among measured electromagnetic fields.

Conclusions

The highest magnetic field intensity measured in this study was related to high-voltage systems and is lower than advised intensity by ICNIRP for occupational exposure. Based on this study, it can be concluded that there are no considerable risks of electromagnetic exposure for operating room personnels.

Modeled and perceived RF-EMF, noise and air pollution and symptoms in a population cohort. Is perception key in predicting symptoms?

BACKGROUND

Psychosocial research has shown that perceived exposure can influence symptom reporting, regardless of actual exposure. The impact of this phenomenon on the interpretation of results from epidemiological research on environmental determinants of symptoms is unclear.

OBJECTIVE

Our aim was to compare associations between modeled exposures, the perceived level of these exposures and reported symptoms (non-specific symptoms, sleep disturbances, and respiratory symptoms) for three different environmental exposures (radiofrequency electromagnetic fields (RF-EMF), noise, and air pollution). These environmental exposures vary in the degree to which they can be sensorially observed.

METHODS

Participant characteristics, perceived exposures, and self-reported health were assessed with a baseline (n = 14,829, 2011/2012) and follow-up (n = 7905, 2015) questionnaire in the Dutch population-based Occupational and Environmental Health Cohort (AMIGO). Environmental exposures were estimated at the home address using spatial models. Cross-sectional and longitudinal regression models were used to examine the associations between modeled and perceived exposures, and reported symptoms.

RESULTS

The extent to which exposure sources could be observed by participants likely influenced correlations between modeled and perceived exposure as correlations were moderate for air pollution (r_Sp = 0.34) and noise (r_Sp = 0.40), but less so for RF-EMF (r_Sp = 0.11). Perceived exposures were consistently associated with increased symptom scores (respiratory, sleep, non-specific). Modeled exposures, except RF-EMF, were associated with increased symptom scores, but these associations disappeared or strongly diminished when accounted for perceived exposure in the analyses.

DISCUSSION

Perceived exposure has an important role in symptom reporting. When environmental determinants of symptoms are studied without acknowledging the potential role of both modeled and perceived exposures, there is a risk of bias in health risk assessment. However, the etiological role of exposure perceptions in relation to symptom reporting requires further research.

"These Power Lines Make Me Ill": A Typology of Residents' Health Responses to a New High-Voltage Power Line

Little attention has been devoted to the potential diversity in residents' health responses when exposed to an uncertain environmental health risk. The present study explores whether subgroups of residents respond differently to a new high-voltage power line (HVPL) being put into operation. We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it was put into operation. Residents living nearby (0-300 m, n = 229) filled out questionnaires about their health and their perception of the environment. We applied latent class growth models to investigate heterogeneity in the belief that health complaints were caused by a power line. Classes were compared on a wide range of variables relating to negative-oriented personality traits, perceived physical and mental health, and perceptions of the environment. We identified five distinct classes of residents, of which the largest (49%) could be described as emotionally stable and healthy with weak responses to the introduction of a new power line. A considerable minority (9%) responded more strongly to the new line being activated. Residents in this class had heard more about the health effects of power lines beforehand, were more aware of the activation of the new line, and reported a decrease in perceived health afterwards. Based on our findings we can conclude that there is a considerable heterogeneity in health responses to a new HVPL. Health risk perceptions appear to play an important role in this typology, which has implications for risk management.

Modeled and Perceived Exposure to Radiofrequency Electromagnetic Fields From Mobile-Phone Base Stations and the Development of Symptoms Over Time in a General Population Cohort

We assessed associations between modeled and perceived exposure to radiofrequency electromagnetic fields (RF-EMF) from mobile-phone base stations and the development of nonspecific symptoms and sleep disturbances over time. A population-based Dutch cohort study, the Occupational and Environmental Health Cohort Study (AMIGO) (n = 14,829; ages 31-65 years), was established in 2011/2012 (T0), with follow-up of a subgroup (n = 3,992 invited) in 2013 (T1; n = 2,228) and 2014 (T2; n = 1,740). We modeled far-field RF-EMF exposure from mobile-phone base stations at the home addresses of the participants using a 3-dimensional geospatial model (NISMap). Perceived exposure (0 = not at all; 6 = very much), nonspecific symptoms, and sleep disturbances were assessed by questionnaire. We performed cross-sectional and longitudinal analyses, including fixed-effects regression. We found small correlations between modeled and perceived exposure in AMIGO participants at baseline (n = 14,309; rSpearman = 0.10). For 222 follow-up participants, modeled exposure increased substantially (>0.030 mW/m2) between T0 and T1. This increase in modeled exposure was associated with an increase in perceived exposure during the same time period. In contrast to modeled RF-EMF exposure from mobile-phone base stations, perceived exposure was associated with higher symptom reporting scores in both cross-sectional and longitudinal analyses, as well as with sleep disturbances in cross-sectional analyses.

Clinically defined non-specific symptoms in the vicinity of mobile phone base stations: A retrospective before-after study

The number of mobile phone base station(s) (MPBS) has been increasing to meet the rapid technological changes and growing needs for mobile communication. The primary objective of the present study was to test possible changes in prevalence and number of NSS in relation to MPBS exposure before and after increase of installed MPBS antennas. A retrospective cohort study was conducted, comparing two time periods with high contrast in terms of number of installed MPBS. Symptom data were based on electronic health records from 1069 adult participants, registered in 9 general practices in different regions in the Netherlands. All participants were living within 500m from the nearest bases station. Among them, 55 participants reported to be sensitive to MPBS at T1. A propagation model combined with a questionnaire was used to assess indoor exposure to RF-EMF from MPBS at T1. Estimation of exposure at T0 was based on number of antennas at T0 relative to T1. At T1, there was a >30% increase in the total number of MPBS antennas. A higher prevalence for most NSS was observed in the MPBS-sensitive group at T1 compared to baseline. Exposure estimates were not associated with GP-registered NSS in the total sample. Some significant interactions were observed between MPBS-sensitivity and exposure estimates on risk of symptoms. Using clinically defined outcomes and a time difference of >6years it was demonstrated that RF-EMF exposure to MPBS was not associated with the development of NSS. Nonetheless, there was some indication for a higher risk of NSS for the MPBS-sensitive group, mainly in relation to exposure to UMTS, but this should be interpreted with caution. Results have to be verified by future longitudinal studies with a particular focus on potentially susceptible population subgroups of large sample size and integrated exposure assessment.

Nocebo responses to high-voltage power lines: Evidence from a prospective field study

BACKGROUND

Experimental studies suggest that nocebo responses might occur after exposure to equipment emitting electromagnetic fields such as high voltage power lines (HVPLs) or mobile phone base stations.

OBJECTIVES

The present study investigates to what extent health responses to a new HVPL can be explained by beliefs of residents regarding the health effects of HVPLs.

METHODS

We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it has been put into operation. Residents living near (0-300 m, n=229; 300-500 m, n=489) and farther away (500-2000 m, n=536) filled out questionnaires about their health and their beliefs about the negative health effects of power lines. Longitudinal mediation models were applied to investigate to what extent these beliefs could explain a change in reported symptoms after the new line was put into operation.

RESULTS

Significant (p<.01) indirect effects were found for proximity on the increase in reported cognitive (R(2)=0.41) and somatic (R(2)=0.79) symptoms after the power line was put into operation through an increase in the belief that power lines causes health effects. The direct effects of proximity on an increase in reported symptoms were not significant.

CONCLUSIONS

Our findings suggest that increases in reported health complaints after a new HVPL has been put into operation can be explained by nocebo mechanisms. Future field studies are needed to know whether our findings extend to other environmental health issues in a community.

Somatic symptom reports in the general population: Application of a bi-factor model to the analysis of change

OBJECTIVE

To investigate the latent structure of somatic symptom reports in the general population with a bi-factor model and apply the structure to the analysis of change in reported symptoms after the emergence of an uncertain environmental health risk.

METHODS

Somatic symptoms were assessed in two general population environmental health cohorts (AMIGO, n=14,829 & POWER, n=951) using the somatization scale of the four-dimensional symptom questionnaire (4DSQ-S). Exploratory bi-factor analysis was used to determine the factor structure in the AMIGO cohort. Multi-group and longitudinal models were applied to assess measurement invariance. For a subsample of residents living close to a newly introduced power line (n=224), we compared a uni- and multidimensional method for the analysis of change in reported symptoms after the power line was put into operation.

RESULTS

We found a good fit (RMSEA=0.03, CFI=0.98) for a bi-factor model with one general and three symptom specific factors (musculoskeletal, gastrointestinal, cardiopulmonary). The latent structure was found to be invariant between cohorts and over time. A significant increase (p<.05) was found only for musculoskeletal and gastrointestinal symptoms after the power line was put into operation.

CONCLUSIONS

In our study we found that a bi-factor structure of somatic symptoms reports was equivalent between cohorts and over time. Our findings suggest that taking this structure into account can lead to a more informative interpretation of a change in symptom reports compared to a unidimensional approach.