Polluted places or polluted minds? An experimental sham-exposure study on background psychological factors of symptom formation in ‘Idiophatic Environmental Intolerance attributed to electromagnetic fields’

Associations Among Environmental Exposures and Physical and Psychiatric Symptoms in a Care-Seeking Sample of U.S. Military Veterans

INTRODUCTION

Recent research and policy (e.g., the Sergeant First Class (SFC) Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act) have highlighted the potential health consequences of toxic environmental exposures. The purpose of the current study was to assess the self-reported prevalence of such exposures among a sample of U.S. military veterans seeking care at a Veterans Affairs facility and to examine associations between exposures and physical and psychiatric symptoms.

MATERIALS AND METHODS

Participants were 4,647 newly enrolling post-9/11 veterans at the VA San Diego Healthcare System who completed standard clinical screening processes between January 2015 and April 2019. Electronic health screening data, including demographic information, military history, environmental exposures, and physical and psychiatric symptoms, were assessed. t-Tests for continuous variables and chi-square tests for categorical variables were used to compare exposed to unexposed veterans on demographic and military characteristics as well as physical and psychiatric symptoms.

RESULTS

A total of 2,028 veterans (43.6%) reported exposure to environmental toxins during their military service. Analyses revealed a disproportionate burden of exposure on older, male, educated, combat veterans as well as Asian and Native American veterans. Exposure to any type of environmental toxin was associated with more physical symptoms, particularly pain, fatigue, and insomnia, as well as psychiatric symptoms, including moderate depressive symptomology, mild to moderate anxiety, and scores approaching the threshold for likely post-traumatic stress disorder and alcohol misuse.

CONCLUSIONS

The high prevalence and detrimental health correlates of environmental exposures underscore the importance of implementing screening for exposures and providing healthcare services that address the multisystemic nature of exposure-related illness.

Is the rubber hand illusion associated with somatic symptom reporting?

Current approaches to somatic symptom perception conceptualize somatic symptoms partly as somato-visceral or body illusions evoked by an interaction between bottom-up (sensory) and top-down (expectations, attention) processes. Similar processes of multisensory integration are assumed to contribute to the rubber hand illusion (RHI). Findings concerning the strength and direction of associations between these two phenomena, symptom perception and the RHI, are equivocal. Individuals of a non-clinical sample (N = 63; 56% females; Mage = 20.4; SD = 1.6) completed the Patient Health Questionnaire Somatic Symptom Scale (PHQ-15) and participated in an experiment that evoked the RHI. In repeated measures analyses of variance with the PHQ-15 score as covariate, no significant interaction effects between the PHQ-15 score and indicators of the RHI, i.e., proprioceptive drift (F(1,61) < 0.001 p = 0.993, partial η2 < 0.001; BF10 = 0.307), felt body ownership(F(1,59) = 0.043, p = 0.836, partial η2 = 0,001; BF10 = 0.501), and felt body disownership (F(1,59) = 0.148, p = 0.702, partial η2 = 0.002; BF10 = 1.972) were found. Overall, frequentist and Bayesian analysis indicated that the support for a possible association between the PHQ-15 and indicators of the RHI remains inconclusive, i.e., neither the null nor the alternative hypotheses were sufficiently supported. At least in this non-clinical sample, the association between somatic symptom distress and the strength of the RHI appears so weak (perhaps non-existing), that both phenomena (somatic symptom distress and the RHI) appear distinct and largely unrelated.

Are there placebo or nocebo effects in balancing performance?

Placebo and nocebo effects could influence the perceived, actual, or both postural stabilities. Therefore, this experiment examined whether postural stability is susceptible to placebo and nocebo effects. Driven by expectations, these cognitions could influence the motor stability of people in physical rehabilitation and those with motion instability. We randomly assigned 78 participants to a placebo, nocebo, or control group. Then, we applied a sham sports cream with positive, negative, or neutral instructions about its impact on balance. Next, we tested postural stability with a modified version of the Modified Clinical Test of Sensory Interaction in Balance, including standard, proprioceptive, visual, and vestibular tests before and after the intervention. Further, we measured expected and perceived performance with visual analog scales and assessed trait anxiety, change in state anxiety, optimism, holistic thinking, persistence, and cooperation with questionnaires. The intervention did not affect actual test performances; similarly, trait and state variables and expectations did not have an impact. Furthermore, the experimental manipulation and trait and state variables did not significantly affect perceived performance. However, the association between expectation and perceived performance was strong (ϱ = 0.627, p < 0.001). These findings suggest that postural stability is not susceptible to placebo and nocebo influences. Still, there is a dissociation between objective and subjective performance, showing that expectations impact perceived but not actual performance, which could fuel motivation in rehabilitation settings.

Association between personality traits and placebo effects: a preregistered systematic review and meta-analysis

ABSTRACT

Placebo effects are ubiquitous yet highly variable between individuals and therefore strongly affect clinical trial outcomes such as pain relief. It is unclear whether dispositional psychological traits influence responsiveness to placebo. This preregistered meta-analysis and systematic review synthesized the literature investigating the association between personality traits and placebo effects. Based on 21 studies with 798 participants, we performed formal meta-analyses for 10 different personality traits, including behavioral inhibition, fun seeking, goal-drive persistence, reward responsiveness, empathic concern, empathic fantasy, perspective-taking, personal distress, optimism, and anxiety. We did not find evidence of associations between any of these traits and magnitude of placebo effects, which was supported by equivalence tests. Furthermore, we did not find evidence for moderating factors such as placebo manipulation type (conditioning or nonconditioning) or condition (pain or nonpain). These findings challenge the notion that personality influences responsiveness to placebos and contradict its utility for identifying placebo "responders" and "nonresponders."

Time course of health complaints attributed to RF-EMF exposure and predictors of electromagnetic hypersensitivity over 10 years in a prospective cohort of Dutch adults

BACKGROUND

Some individuals attribute health complaints to radiofrequency electromagnetic field (RF-EMF) exposure. This condition, known as idiopathic environmental intolerance attributed to RF-EMFs (IEI-RF) or electromagnetic hypersensitivity (EHS), can be disabling for those who are affected. In this study we assessed factors related to developing, maintaining, or discarding IEI-RF over the course of 10 years, and predictors of developing EHS at follow-up using a targeted question without the condition of reporting health complaints attributed to RF-EMF exposure.

METHODS

Participants (n = 892, mean age 50 at baseline, 52 % women) from the Dutch Occupational and Environmental Health Cohort Study AMIGO filled in questionnaires in 2011/2012 (T₀), 2013 (T₁), and 2021 (T₄) where information pertaining to perceived RF-EMF exposure and risk, non-specific symptoms, sleep problems, IEI-RF, and EHS was collected. We fitted multi-state Markov models to represent how individuals transitioned between states ("yes", "no") of IEI-RF.

RESULTS

At each time point, about 1 % of study participants reported health complaints that they attributed to RF-EMF exposure. While this percentage remained stable, the individuals who reported such complaints changed over time: of nine persons reporting health complaints at T₀, only one reported IEI-RF at both T₁ and T₄, and two newly reported health complaints at T₄. Overall, participants had a 95 % chance of transitioning from "yes" to "no" over a time course of 10 years, and a chance of 1 % of transitioning from "no" to "yes". Participants with high perceived RF-EMF exposure and risk had a general tendency to move more frequently between states.

CONCLUSIONS

We observed a low prevalence of IEI-RF in our population. Prevalence did not vary strongly over time but there was a strong aspect of change: over 10 years, there was a high probability of not attributing symptoms to RF-EMF exposure anymore. IEI-RF appears to be a more transient condition than previously assumed.

Review of the scientific evidence on the individual sensitivity to electromagnetic fields (EHS)

Part of the population considers themselves as sensitive to the man-made electromagnetic radiation (EMF) emitted by powerlines, electric wiring, electric home appliance and the wireless communication devices and networks. Sensitivity is characterized by a broad variety of non-specific symptoms that the sensitive people claim to experience when exposed to EMF. While the experienced symptoms are currently considered as a real life impairment, the factor causing these symptoms remains unclear. So far, scientists were unable to find causality link between symptoms experienced by sensitive persons and the exposures to EMF. However, as presented in this review, the executed to-date scientific studies, examining sensitivity to EMF, are of poor quality to find the link between EMF exposures and sensitivity symptoms of some people. It is logical to consider that the sensitivity to EMF exists but the scientific methodology used to find it is of insufficient quality. It is time to drop out psychology driven provocation studies that ask about feelings-based non-specific symptoms experienced by volunteers under EMF exposure. Such research approach produces only subjective and therefore highly unreliable data that is insufficient to prove, or to disprove, causality link between EHS and EMF. There is a need for a new direction in studying sensitivity to EMF. The basis for it is the notion of a commonly known phenomenon of individual sensitivity, where individuals' responses to EMF depend on the genetic and epigenetic properties of the individual. It is proposed here that new studies, combining provocation approach, where volunteers are exposed to EMF, and high-throughput technologies of transcriptomics and proteomics are used to generate objective data, detecting molecular level biochemical responses of human body to EMF.

An idiographic approach to idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) part I. Environmental, psychosocial and clinical assessment of three individuals with severe IEI-EMF

IEI-EMF refers to an environmental illness whose primary feature is the occurrence of symptoms that are attributed to exposure to weak electromagnetic fields (EMFs). There is a growing evidence that this condition is characterized by marked individual differences thus a within-subject approach might add important information beyond the widely used nomothetic method. A mixed qualitative/quantitative idiographic protocol with a threefold diagnostic approach was tested with the participation of three individuals with severe IEI-EMF. In this qualitative paper, the environmental, psychosocial, and clinical aspects are presented and discussed (results of ecological momentary assessment are discussed in Part II of this study). For two participants, psychopathological factors appeared to be strongly related to the condition. Psychological assessment indicated a severe pre-psychotic state with paranoid tendencies, supplemented with a strong attentional focus on bodily sensations and health status. The psychological profile of the third individual showed no obvious pathology. Overall, the findings suggest that the condition might have uniformly been triggered by serious psychosocial stress for all participants. Substantial aetiological differences among participants with severe IEI-EMF were revealed. The substantial heterogeneity in the psychological and psychopathological profiles associated with IEI-EMF warrants the use of idiographic multimodal assessments in order to better understand the different ways of aetiology and to facilitate person-taylored treatments.

An idiographic approach to Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) Part II. Ecological momentary assessment of three individuals with severe IEI-EMF

IEI-EMF refers to a self-reported sensitivity characterized by attribution of non-specific physical symptoms to exposure to weak EMFs. The majority of empirical results do not support the existence of a causal relationship between EMF and IEI-EMF. However, this conclusion was drawn from environmental and experimental studies that are not without methodological limitations. In the current study, as part of a complex biopsychosocial approach, an ecological momentary assessment (EMA) protocol was applied for the investigation of the temporal relationship between actual radio frequency (RF) EMF exposure and IEI-EMF, at the individual level. Continuous measurement of autonomic variables by holter electrocardiogram (ECG) monitors and the ambient RF EMF by personal dosimeters, as well as repeated (8/day) paper-and-pencil assessments of momentary internal states (symptoms, mood, perceived EMF intensity) and situational factors was conducted for 21 days with the participation of three individuals with severe IEI-EMF. Temporal relationships were examined by time series analyses. For two participants, the results did not support the association between the suspected EMF frequency range(s) and symptom reports. Nevertheless, the results revealed a reverse association with respect to another frequency range (GSM900 downlink), which contradicts the IEI-EMF condition. Autonomic activation related findings were inconsistent. For the third participant, the claimed association was partly supported, both for symptom reports and autonomic reactions (UMTS downlink, total RF; RMS values). The findings of this study suggest that IEI-EMF does not have a unitary aetiology. For certain individuals, a biophysical background cannot be excluded, whereas no such underlying factor appears to be at work for others. EMA is a useful method for the investigation of the aetiology of IEI-EMF.

Psychological models of development of idiopathic environmental intolerances: Evidence from longitudinal population-based data

The origin of idiopathic environmental intolerances (IEIs) is an open question. According to the psychological approaches, various top-down factors play a dominant role in the development of IEIs. The general psychopathology model assumes a propensity towards mental ill-health (negative affectivity) increases the probability of developing IEIs. The attribution model emphasizes the importance of mistaken attribution of experienced somatic symptoms; thus, more symptoms should lead to more IEIs. Finally, the nocebo model highlights the role of expectations in the development of IEIs. In this case, worries about the harmful effects of environmental factors are assumed to evoke IEIs. We estimated cross-lagged panel models with latent variables based on longitudinal data obtained at two time points (six years apart) from a large near-representative community sample to test the hypothesized associations. Indicators of chemical intolerance, electromagnetic hypersensitivity, and sound sensitivity fit well under a common latent factor of IEIs. This factor, in turn, showed considerable temporal stability. However, whereas a positive association was found between IEIs and increased somatic symptoms and modern health worries six years later, the changes therein could not be predicted as hypothesized by the three psychological models. We discuss the implications of these results, as well as methodological aspects in the measurement and prediction of change in IEIs.

Perceived environmental pollution and subjective cognitive decline (SCD) or SCD-related functional difficulties among the general population

This study aimed to determine whether perceived environmental pollution is associated with subjective cognitive decline (SCD) or SCD-related functional difficulties. We conducted a cross-sectional study using data from a nationwide sample of 191,054 individuals aged ≥19 years from the 2018 Korea Community Health Survey. Perceived air, water, soil, noise, and green space pollution was assessed. To investigate the dose-response effect of the amount of perceived environmental pollution, we determined whether an increasing number of types of perceived environmental pollution also increased the odds of having SCD or SCD-related functional difficulties. Among the 191,054 individuals, the prevalence of SCD and SCD-related functional difficulties was 17.7% (N = 33,853) and 2.2% (N = 4139), respectively. Perception of air, soil, or noise pollution was significantly associated with SCD. However, the perception of any type of environmental pollution was not significantly associated with SCD-related functional difficulties. With regard to a dose-response effect, individuals perceiving a greater number of types of environmental pollution had significantly higher odds of SCD or SCD-related functional difficulties. This association was notably more evident in the younger age group.

Association between perceived environmental pollution and poor sleep quality: results from nationwide general population sample of 162,797 people

OBJECTIVE/BACKGROUND

Perceived environmental pollution may play a significant role in understanding environmentally induced health-related symptoms. This study aimed to determine whether perceived environmental pollution is associated with poor sleep quality.

METHODS

We conducted a cross-sectional study using data from a nationwide sample of 162,797 individuals aged ≥19 years from the 2018 Korea Community Health Survey. The Pittsburgh Sleep Quality Index was used for assessing sleep quality. Five types of perceived environmental pollutants involving air, water, soil, noise, and green space were assessed. We investigate the association between perceived environmental pollution and poor sleep quality. We also investigated whether an increasing number of perceived environmental pollutants magnified the odds of poor sleep quality.

RESULTS

The prevalence of poor sleep quality was 42.7% (n = 69,554), and 15.6%, 10.1%, 11.9%, 23.0%, and 11.5% reported perceived environmental pollution concerning air, water, soil, noise, and green space, respectively. A perception of air, soil, or noise pollution was significantly associated with poor sleep quality. In addition, those perceiving a greater number of environmental pollutants had significantly higher odds of poor sleep quality. Notably, this association was magnified in individuals living in rural areas.

CONCLUSIONS

Perceived environmental pollution was significantly associated with poor sleep quality. Our results suggest that a more comprehensive exposure to environmental pollution may not only have a worse effect on health outcomes including sleep quality.

Somatosensory Illusions Elicited by Sham Electromagnetic Field Exposure: Experimental Evidence for a Predictive Processing Account of Somatic Symptom Perception

OBJECTIVE

According to the predictive processing theory of somatic symptom generation, body sensations are determined by somatosensory input and central nervous predictions about this input. We examined how expectations shape predictions and consequently bodily perceptions in a task eliciting illusory sensations as laboratory analogue of medically unexplained symptoms.

METHODS

Using the framework of signal detection theory, the influence of sham Wi-Fi on response bias (c) and somatosensory sensitivity (d') for tactile stimuli was examined using the somatic signal detection task (SSDT). A healthy student sample (n = 83) completed the SSDT twice (sham Wi-Fi on/off) in a randomized order after watching a film that promoted adverse health effects of electromagnetic fields.

RESULTS

When expecting a Wi-Fi signal to be present, participants showed a significantly more liberal response bias c (p = .010, ηp2 = 0.08) for tactile stimuli in the SSDT as evidence of a higher propensity to experience somatosensory illusions. No significant alteration of somatosensory sensitivity d' (p = .76, ηp2 < 0.002) was observed.

CONCLUSIONS

Negative expectations about the harmfulness of electromagnetic fields may foster the occurrence of illusory symptom perceptions via alterations in the somatosensory decision criterion. The findings are in line with central tenets of the predictive processing account of somatic symptom generation. This account proposes a decoupling of percept and somatosensory input so that perception becomes increasingly dependent on predictions. This biased perception is regarded as a risk factor for somatic symptom disorders.

Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF)

The exact causes of Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF, i.e., experience of somatic symptoms attributed to low-level electromagnetic fields) are still unknown. Psychological causation such as nocebo effects seem plausible. This study aimed to experimentally induce a nocebo effect for somatic symptom perception and examined whether it was reproducible after one week. We also examined whether these effects were associated with increased sympathetic activity and whether interoceptive accuracy (IAcc) moderated these relationships. Participants were recruited from the general population and instructed that electromagnetic exposure can enhance somatosensory perception. They participated twice in a cued exposure experiment with tactile stimulation and sham WiFi exposure in 50% of trials. The two sessions were scheduled one week apart (session 1: N = 65, session 2: N = 63). Before session 1, participants watched either a 6-min film on adverse health effects of EMF or a neutral film on trade of mobile phones. IAcc was assessed with the heartbeat detection paradigm. Electrodermal activity served as a measure of sympathetic activation. Evidence for a nocebo effect (i.e., increased self-reported intensity and aversiveness and electrodermal activity) during sham WiFi exposure was observed in both sessions. IAcc moderated the nocebo effect, depending on stimulus intensity. Contrary to previous findings, no difference emerged between the health-related EMF and the neutral films. Based on negative instructions, somatic perception and physiological responding can be altered. This is consistent with the assumption that IEI-EMF could be due to nocebo effects, suggesting an important role for psychological interventions.

Letter to the Study by Hyvönen et al. on Moisture Damage and MCS

Due to the significant methodological problems in the empirical part of the paper and the very selective literature review, the conclusions of the paper are mostly unsupported.

Psychosocial treatments for employees with non-specific and persistent physical symptoms associated with indoor air: A randomised controlled trial with a one-year follow-up

OBJECTIVE

Persistent physical symptoms (PPS) associated with indoor air without an adequate pathophysiological- or environmental-related explanation may lead to work disability and decreased health-related quality of life (HRQoL). We attempted to assess the effect of cognitive behavioural therapy (CBT) for PPS and also psychoeducation (PE) on these symptoms involving disability.

METHOD

The intention-to-treat (ITT) sample included 52 employees recruited from an occupational healthcare service randomised as either controls undergoing treatment as usual (TAU) or TAU enhanced with CBT or PE. The primary outcome was HRQoL measuring the severity of symptoms and restrictions in everyday life caused by them. Secondary outcomes included depressive, anxiety and insomnia symptoms, and intolerance to environmental factors, assessed at baseline and at 3-, 6- and 12-month follow-ups.

RESULTS

At the 12-month follow-up assessment point, no statistically significant differences between treatments emerged following adjustment for gender, age, and HRQoL before the waiting period in the ITT analysis [F(2,46)=2.89, p=.07]. The secondary analysis revealed a significant improvement in HRQoL in the combined intervention group as compared with controls [F(1,47)=5.06, p=.03, g=0.41]. In total, 15% of participants dropped out during follow-up.

CONCLUSIONS

The results suggest that CBT for PPS or PE might not have a robust effect on HRQoL in PPS associated with indoor air, but the study did not achieve the planned power. Despite difficulties during the recruitment process, the final dropout rates remained low, and participants positively evaluated CBT, suggesting that it represents an acceptable treatment to them. Trial status This study was registered at the ClinicalTrials.gov registry (NCT02069002).

The influence of personality traits on the placebo/nocebo response: A systematic review

OBJECTIVE

Some people might be more prone to placebo and nocebo responses than others depending on their personality traits. We aimed to provide a systematic review on the influence of personality traits on placebo and nocebo responses in controlled and uncontrolled studies.

METHODS

We conducted a systematic literature search in the databases CINAHL, AMED, PsycINFO and EMBASE for relevant publications published between January 1997 and March 2018. For all included papers, we conducted an additional forward search.

RESULTS

After screening 407 references, we identified 24 studies. The Big Five (i.e., neuroticism, extraversion, openness to experience, agreeableness and conscientiousness) and optimism were the most frequently investigated personality traits. Several studies found a positive association between optimism and the placebo response. Furthermore, we found that higher anxiety was associated with increased nocebo responses.

CONCLUSION

Evidence points to a possible association between optimism and the placebo response. Therefore, further emphasising the investigation of the influence of optimism on the placebo/nocebo response seems warranted. For clinical practice, the impact of anxiety on the nocebo response might be important to identify patients who might be more prone to experiencing side effects of medical treatments.

Methodological limitations in experimental studies on symptom development in individuals with idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) - a systematic review

BACKGROUND

Hypersensitivity to electromagnetic fields (EMF) is a controversial condition. While individuals with idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) claim to experience health complaints upon EMF exposure, many experimental studies have found no convincing evidence for a physical relation. The aim of this systematic review was to evaluate methodological limitations in experimental studies on symptom development in IEI-EMF individuals that might have fostered false positive or false negative results. Furthermore, we compared the profiles of these limitations between studies with positive and negative results.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guided the methodological conduct and reporting. Eligible were blinded experimental studies that exposed individuals with IEI-EMF to different EMF exposure levels and queried the development of symptoms during or after each exposure trial. Strengths and limitations in design, conduct and analysis of individual studies were assessed using a customized rating tool.

RESULTS

Twenty-eight studies met the eligibility criteria and were included in this review. In many studies, both with positive and negative results, we identified methodological limitations that might have either fostered false or masked real effects of exposure. The most common limitations were related to the selection of study participants, the counterbalancing of the exposure sequence and the effectiveness of blinding. Many studies further lacked statistical power estimates. Methodically sound studies indicated that an effect of exposure is unlikely.

CONCLUSION

Overall, the evidence points towards no effect of exposure. If physical effects exist, previous findings suggest that they must be very weak or affect only few individuals with IEI-EMF. Given the evidence that the nocebo effect or medical/mental disorders may explain the symptoms in many individuals with IEI-EMF, additional research is required to identify the various factors that may be important for developing IEI-EMF and for provoking the symptoms. We recommend the identification of subgroups and exploring IEI-EMF in the context of other idiopathic environmental intolerances. If further experimental studies are conducted, they should preferably be performed at the individual level. In particular, to increase the likelihood of detecting hypersensitive individuals, if they exist, we encourage researchers to achieve a high credibility of the results by minimizing sources of risk of bias and imprecision.

Residential green space and seasonal distress in a cohort of tree pollen allergy patients

BACKGROUND

Residential green space may improve human health, for example by promoting physical activity and by reducing stress. Conversely, residential green space may increase stress by emitting aeroallergens and exacerbating allergic disease. Here we examine impacts of exposure to residential green space on distress in the susceptible subpopulation of adults sensitized to tree pollen allergens.

METHODS

In a panel study of 88 tree pollen allergy patients we analyzed self-reported mental health (GHQ-12), perceived presence of allergenic trees (hazel, alder, birch) near the residence and residential green space area within 1 km distance [high (≥3 m) and low (<3 m) green]. Results were adjusted for patients' background data (gender, age, BMI, smoking status, physical activity, commuting distance, education level, allergy medication use and chronic respiratory problems) and compared with distress in the general population (N = 2467).

RESULTS

Short-term distress [mean GHQ-12 score 2.1 (95% confidence interval 1.5-2.7)] was higher in the study population than in the general population [1.5 (1.4-1.7)]. Residential green space had protective effects against short-term distress [high green, per combined surface area of 10 ha: adjusted odds ratio OR = 0.94 (95% confidence interval 0.90-0.99); low green, per 10 ha: OR = 0.85 (0.78-0.93)]. However, distress was higher in patients who reported perceived presence of allergenic trees near their residence [present vs. absent: OR = 2.04 (1.36-3.07)].

CONCLUSIONS

Perceived presence of allergenic tree species in the neighbourhood of the residence of tree pollen allergy patients modulates the protective effect of residential green space against distress during the airborne tree pollen season.

Modern health worries: A systematic review

OBJECTIVE

Modern health worries (MHWs) refer to people's concerns about possible harmful effects of modern technologies, and are widespread in the developed countries. The aim of the present work was to provide comprehensive, yet integrated understanding for MHWs and associated factors.

METHODS

Following the PRISMA guideline, a systematic review was conducted based on 48 empirical articles published between 2001 and 2018 (Prospero registration number: CRD42018103756). All empirical studies were included that (1) were published between 2001 and 2018 in peer-reviewed scientific journals in English, German, or Hungarian, (2) used the Modern Health Worries Scale or any of its sub-scales, and (3) assessed associations between MHWs and other constructs and/or compared criterion groups (i.e. purely psychometric studies were excluded).

RESULTS

The results from the review suggest that female gender, age, somatic symptom distress and idiopathic environmental intolerances, holistic thinking, and paranoid beliefs are positively associated with MHWs, whereas educational qualification and the five major dimensions of personality appear not to be.

CONCLUSION

Scientific inquiry on the MHWs phenomenon is still in its descriptive-explorative phase; more rigorously designed studies are needed. The presented theoretical framework integrates illness-related and holistic thinking-related aspects of MHWs as a starting point to guide further research in this area.

It is not just the drugs that matter: the nocebo effect

The role of psychological mechanisms in the treatment process cannot be underestimated, the well-known placebo effect unquestionably being a factor in treatment. However, there is also a dark side to the impact of mental processes on health/illness as exemplified by the nocebo effect. This phenomenon includes the emergence or exacerbation of negative symptoms associated with the therapy, but arising as a result of the patient's expectations, rather than being an actual complication of treatment. The exact biological mechanisms of this process are not known, but cholecystokinergic and dopaminergic systems, changes in the HPA axis, and the endogenous secretion of opioids are thought to be involved. The nocebo effect can affect a significant proportion of people undergoing treatment, including cancer patients, leading in some cases to the cessation of potentially effective therapy, because of adverse effects that are not actually part of the biological effect of treatment. In extreme cases, as a result of suggestions and expectations, a paradoxical effect, biologically opposite to the mechanism of the action of the drug, may occur. In addition, the nocebo effect may significantly interfere with the results of clinical trials, being the cause of a significant proportion of complications reported. Knowledge of the phenomenon is thus necessary in order to facilitate its minimalization and thus improve the quality of life of patients and the effectiveness of treatment.

How to prevent, minimize, or extinguish nocebo effects in pain: a narrative review on mechanisms, predictors, and interventions

Possible factors that contribute to nocebo effects on pain are explored. Strategies that can prevent, minimize, or extinguish nocebo effects in clinical settings are suggested.

Nocebo effects, such as side effects due to negative expectations regarding the pain treatment, are a concern for health care providers and come with significant costs. This narrative review focuses on underlying mechanisms and possible factors that contribute to the susceptibility to the nocebo effect on pain and related outcomes and suggests strategies that can prevent, minimize, or extinguish nocebo effects in clinical settings. Nocebo effects are the result of psychological (eg, conditioning, verbal suggestions, and observational learning) and neurobiological (eg, cholecystokinin and dopamine regulation) mechanisms. Evidence from clinical and experimental studies lead to various recommendations and strategies to alter the nocebo effect in order to optimize pain treatments, such as providing patients with enhanced information, optimizing patient–physician communication and relationships, and offering psychoeducation on coping skills in order to manage patient expectations. The current literature from both clinical and experimental studies provides a better understanding of the nocebo effect and possible factors that modulate its strength on treatment outcomes. This allows for the development of evidence-based strategies aimed at the prevention, minimization, and treatment of the nocebo effect in pain conditions and possible other somatic disorders.

Is the built environment associated with morbidity and mortality? A systematic review of evidence from Germany

The empirical evidence on this relationship mainly comes from Anglo-American countries whereas evidence from Germany is only emerging. Our objective is to provide a narrative overview and critical appraisal of the existing empirical evidence on the relationship between the built environment and morbidity/mortality in Germany. We conducted a systematic literature search where we included all empirical studies that linked the built environment aspects with morbidity or mortality outcomes. Findings were summarized and critically evaluated according to the Newcastle Ottawa Scale. Eighteen studies met the inclusion criteria and underwent in-depth analysis. Findings indicate that traffic exposure and green space tend to be associated with acute respiratory symptoms but not with chronic respiratory conditions. Evidence was inconsistent for the role of infrastructural aspects and urbanicity. Our review confirms the well-established association between traffic and respiratory health. Yet, the consistency between self-reported and objective measures of respiratory health should be investigated in more detail.

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.

Can explicit suggestions about the harmfulness of EMF exposure exacerbate a nocebo response in healthy controls?

While there has been consistent evidence that symptoms reported by individuals who suffer from Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) are not caused by EMF and are more closely associated with a nocebo effect, whether this response is specific to IEI-EMF sufferers and what triggers it, remains unclear. The present experiment tested whether perceived EMF exposure could elicit symptoms in healthy participants, and whether viewing an 'alarmist' video could exacerbate a nocebo response. Participants were randomly assigned to watch either an alarmist (N = 22) or control video (N = 22) before completing a series of sham and active radiofrequency (RF) EMF exposure provocation trials (2 open-label, followed by 12 randomized, double-blind, counterbalanced trials). Pre- and post-video state anxiety and risk perception, as well as belief of exposure and symptom ratings during the open-label and double-blind provocation trials, were assessed. Symptoms were higher in the open-label RF-ON than RF-OFF trial (p < .001). No difference in either symptoms (p = .183) or belief of exposure (p = .144) was observed in the double-blind trials. Participants who viewed the alarmist video had a significant increase in symptoms (p = .041), state anxiety (p < .01) and risk perception (p < .001) relative to the control group. These results reveal the crucial role of awareness and belief in the presentation of symptoms during perceived exposure to EMF, showing that healthy participants exhibit a nocebo response, and that alarmist media reports emphasizing adverse effects of EMF also contribute to a nocebo response.

Longitudinal associations between risk appraisal of base stations for mobile phones, radio or television and non-specific symptoms

INTRODUCTION

Studies found that higher risk appraisal of radiofrequency electromagnetic fields is associated with reporting more non-specific symptoms such as headache and back pain. There is limited data available on the longitudinal nature of such associations and what aspects of risk appraisal and characteristics of subjects are relevant.

OBJECTIVE

To examine cross-sectional and longitudinal associations between risk appraisal measures and non-specific symptoms, and assess the role of subject characteristics (sex, age, education, trait negative affect) in a general population cohort.

METHODS

This study was nested in the Dutch general population AMIGO cohort that was established in 2011/2012, when participants were 31-65 years old. We studied a sample of participants (n = 1720) who filled in two follow-up questionnaires in 2013 and 2014, including questions about perceived exposure, perceived risk, and health concerns as indicators of risk appraisal of base stations, and non-specific symptoms.

RESULTS

Perceived exposure, perceived risk, and health concerns, respectively, were associated with higher symptom scores in cross-sectional and longitudinal analyses. Only health concerns (not perceived exposure and perceived risk) temporally preceded high symptom scores and vice versa. Female sex, younger age, higher education, and higher trait negative affect were associated with higher risk appraisal of mobile phone base stations.

DISCUSSION

The findings in this study strengthen the evidence base for cross-sectional and longitudinal associations between higher risk appraisal and non-specific symptoms in the general population. However, the directionality of potential causal relations in non-sensitive general population samples should be examined further in future studies, providing information to the benefit of risk communication strategies.

The nocebo effect: a clinical challenge in the era of biosimilars

INTRODUCTION

The nocebo effect is defined as a negative effect of a pharmacological or non-pharmacological medical treatment that is induced by patients' expectations, and that is unrelated to the physiological action of the treatment. The nocebo effect is an important clinical challenge in the current era of biosimilars. Areas covered: This review aims to answer five key questions about the nocebo effect, namely to reveal its definition, pathophysiology, clinical relevance, contributing factors, and management. Expert commentary: The nocebo effect lowers patients' quality of life and negatively affects treatment adherence rates in biosimilar-treated patients. It may negatively impact on the cost-savings of biosimilars. Health-care providers in charge of biosimilar-treated patients need to be aware of the nocebo effect and adopt strategies to minimize it. They have to be well-informed and confident about the existing evidence about biosimilars. A good patient-physician relationship will improve patients' acceptance of biosimilars, and limits the risk of inappropriate negative bias and the nocebo effect.

Symptom Presentation in Idiopathic Environmental Intolerance With Attribution to Electromagnetic Fields: Evidence for a Nocebo Effect Based on Data Re-Analyzed From Two Previous Provocation Studies

Individuals with idiopathic environmental illness with attribution to electromagnetic fields (IEI-EMF) claim they experience adverse symptoms when exposed to electromagnetic fields (EMFs) from mobile telecommunication devices. However, research has consistently reported no relationship between exposure to EMFs and symptoms in IEI-EMF individuals. The current study investigated whether presence of symptoms in IEI-EMF individuals were associated with a nocebo effect. Data from two previous double-blind provocation studies were re-analyzed based on participants' judgments as to whether or not they believed a telecommunication base station was "on" or "off". Experiment 1 examined data in which participants were exposed to EMFs from Global System for Mobile Communication, Universal Mobile Telecommunications System, and sham base station signals. In Experiment 2, participants were exposed to EMFs from Terrestrial Trunked Radio Telecommunications System and sham base station signals. Our measures of subjective well-being indicated IEI-EMF participants consistently reported significantly lower levels of well-being, when they believed the base station was "on" compared to "off". Interestingly, control participants also reported experiencing more symptoms and greater symptom severity when they too believed the base station was "on" compared to "off". Thus, a nocebo effect provides a reasonable explanation for the presence of symptoms in IEI-EMF and control participants.

Medicine-related beliefs predict attribution of symptoms to a sham medicine: A prospective study

OBJECTIVES

To investigate a range of possible predictors of nocebo responses to medicines.

DESIGN

Prospective cohort study.

METHODS

In total, 203 healthy adult volunteers completed measures concerning demographics, psychological factors, medicine-related beliefs, baseline symptoms, and symptom expectations before taking a sham pill, described as 'a well-known tablet available without prescription' that was known to be associated with several side effects. Associations between these measures and subsequent attribution of symptoms to the tablet were assessed using a hurdle model consisting of a joint logistic and truncated negative binomial regression.

RESULTS

Men had an increased odds of attributing symptoms to the tablet OR = 1.52, and older participants had decreased odds, OR = 0.97. Medicine-related beliefs were important, with modern health worries, belief that medicines cause harm and perceived sensitivity to medicines associated with increased odds of symptom attribution, OR = 1.02, 1.10, 1.09, respectively. Trust in medicines and pharmaceutical companies decreased the odds of symptom attribution, OR = 0.91, 0.88, respectively. The number of symptoms at baseline and the expected likelihood of symptoms were associated with an increased odds of attributing symptoms to the tablet, OR = 1.07, 1.06, respectively. Anxiety, previous symptom experience, symptom expectations, and modern health worries were also important in predicting the number of symptoms participants attributed to the tablet.

CONCLUSION

It is hard to predict who is at risk of developing nocebo responses to medicines from demographic or personality characteristics. Context-specific factors such as beliefs about and trust in medicines, current symptoms and symptom expectations are more useful as predictors. More work is needed to investigate this in a patient sample. Statement of contribution What is already known on this subject? Many patients report non-specific side effects to their medication which may arise through a nocebo effect. Whether some people are particularly predisposed to experience nocebo effects remains unclear. What does this study add? Demographic and personality characteristics are poor predictors of symptom attribution to a sham medicine. Instead, context-specific factors that concern people's beliefs surrounding medicines, their current symptoms, and symptom expectations are more useful as predictors of symptom attribution.

Does precautionary information about electromagnetic fields trigger nocebo responses? An experimental risk communication study

BACKGROUND

Regarding electromagnetic fields from mobile communication technologies, empirical studies have shown that precautionary information given to lay recipients increases their risk perceptions, i.e. the belief that electromagnetic fields are dangerous. Taking this finding one step further, the current study investigates whether precautionary information also leads to higher symptom perceptions in an alleged exposure situation. Building on existing research on nocebo responses to sham electromagnetic fields, an interaction of the precautionary information with personality characteristics was hypothesised.

METHODS

An experimental design with sham exposure to an electromagnetic field of a WLAN device was deployed. The final sample is constituted by N = 137 participants. Participants received either only basic information about the safety of current WLAN exposure limits or in addition also precautionary information (e.g. 'prefer wired connections if wireless technology can be relinquished'). Subsequently, symptoms and other variables were assessed before and after sham exposure to a WLAN electromagnetic field.

RESULTS

Results are not in favour of the hypothesised effects. There was neither a main effect of precautionary information, nor were there any of the hypothesised interaction effects of precautionary information and personality characteristics on perceived symptoms under sham exposure. Exploratory analyses highlight the role of prior risk perception as a predictor of nocebo responses, and of symptom expectations as a mediator between these two variables.

CONCLUSIONS

As the statistical power to detect even small effects was relatively high, we interpret this as a robust indication that precautionary information does not lead to increased nocebo responses by itself. The implications for health authorities´ communication with the public are discussed.

The neuropsychophysiology of tingling

Tingling is a bodily sensation experienced under a variety of conditions from everyday experiences to experimental and therapeutic situations. It can be induced by both peripheral or afferent (external stimulation, peripheral pathology) and higher cognitive (expectation) processes. The paper summarizes the current scientific knowledge on the neurophysiological and psychological concomitants of the tingling sensation. Four possible models are identified and presented: the afferent, the attention-disclosed, the attention-evoked, and the efferent model. Of these, only the attention-disclosed model, i.e., attention discloses the sensation by opening the gate for suppressed sensory information, appears to be able to explain every aspect of the tingling phenomenon. Terminological issues and the possible role of the tingling phenomenon in medically unexplained symptoms, nocebo and placebo reactions, and body-oriented therapeutic interventions are also discussed.

Somatosensory amplification - An old construct from a new perspective

The paper reviews and summarizes the history and the development of somatosensory amplification, a construct that plays a substantial role in symptom reports. Although the association with negative affect has been supported by empirical findings, another key elements of the original concept (i.e. body hypervigilance and the tendency of focusing on mild body sensations) have never been appropriately addressed. Recent findings indicate that somatosensory amplification is connected with phenomena that do not necessarily include symptoms (e.g. modern health worries, or expectations of symptoms and medication side effects), and also with the perception of external threats. In conclusion, somatosensory amplification appears to refer to the intensification of perceived external and internal threats to the integrity of the body ("somatic threat amplification") rather than amplification of perceived or actual bodily events only. Practical implications of this new approach are also discussed.

Physiological and psychological correlates of attention-related body sensations (tingling and warmth)

Body sensations play an essential role in the subjective evaluation of our physical health, illness, and healing. They are impacted by peripheral somatic and external processes, but they are also heavily modulated by mental processes, e.g., attention, motor control, and emotion. Body sensations, such as tingling, numbness, pulse, and warmth, can emerge due to simply focusing attention on a body part. It is however an open question, if these sensations are connected with actual peripheral changes or happen “only in the mind.” Here, we first tested whether the intensity of such attention-related body sensations is related to autonomic and somatomotor physiological processes and to psychological traits. In this study, attention-related body sensations were not significantly connected to changes in physiology, except warmth sensation, which was linked to decrease in muscle tension. Overall intensity of tingling significantly correlated with body awareness and tendentiously with body–mind practice. This strengthened the hypothesis that attention-related body sensations are more the result of top–down functions, and the connection with peripheral processes is weak. Here, we suggested a novel protocol to examine the effect of manipulating attention on body sensations, which together with our results and discussion can inspire future researches.

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.

Are media reports able to cause somatic symptoms attributed to WiFi radiation? An experimental test of the negative expectation hypothesis

People suffering from idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) experience numerous non-specific symptoms that they attribute to EMF. The cause of this condition remains vague and evidence shows that psychological rather than bioelectromagnetic mechanisms are at work. We hypothesized a role of media reports in the etiology of IEI-EMF and investigated how somatosensory perception is affected. 65 healthy participants were instructed that EMF exposure can lead to enhanced somatosensory perception. Participants were randomly assigned to watch either a television report on adverse health effects of EMF or a neutral report. During the following experiment, participants rated stimulus intensities of tactile (electric) stimuli while being exposed to a sham WiFi signal in 50% of the trials. Sham WiFi exposure led to increased intensity ratings of tactile stimuli in the WiFi film group, especially in participants with higher levels of somatosensory amplification. Participants of the WiFi group reported more anxiety concerning WiFi exposure than the Control group and tended to perceive themselves as being more sensitive to EMF after the experiment compared to before. Sensational media reports can facilitate enhanced perception of tactile stimuli in healthy participants. People tending to perceive bodily symptoms as intense, disturbing, and noxious seem most vulnerable. Receiving sensational media reports might sensitize people to develop a nocebo effect and thereby contribute to the development of IEI-EMF. By promoting catastrophizing thoughts and increasing symptom-focused attention, perception might more readily be enhanced and misattributed to EMF.

Nature relatedness is connected with modern health worries and electromagnetic hypersensitivity

Although nature relatedness is considered a positive characteristic, its relationship to constructs involving worries about the negative effects of artificial environmental factors is also feasible. A questionnaire assessing modern health worries, electrosensitivity, somatosensory amplification, spirituality, and nature relatedness was completed by 510 individuals. Nature relatedness was related to electrosensitivity, modern health worries, and spirituality. In a binary logistic regression analysis, somatosensory amplification, modern health worries, and nature relatedness were associated with electrosensitivity, and nature relatedness moderated the connection between modern health worries and electrosensitivity. In naive representations, “natural” might be associated with health, whereas “modern” and “artificial” evoke negative associations.

Attribution-Based Nocebo Effects. Perceived Effects of a Placebo Pill and a Sham Magnetic Field on Cognitive Performance and Somatic Symptoms

BACKGROUND

Negative non-specific (nocebo-like) effects of medications and electromagnetic fields are often described as results of mistaken attribution.

PURPOSE

The current study aimed to find empirical evidence supporting this theory.

METHOD

Participants completed questionnaires assessing modern health worries, health anxiety, and somatosensory amplification, were assigned to one of three conditions (placebo pill with sedative information, sham magnetic field, or control), and completed a 14-min vigilance task. Changes in physiological arousal (heart rate, heart rate variability, and skin conductance) and reported symptoms were also measured. Finally, causal attributions concerning cognitive performance and reported symptoms were assessed.

RESULTS

No increase in symptom reports and physiological arousal was measured in the two intervention groups. A perceived negative effect on cognitive performance was attributed to both sham conditions, and attributions were connected to modern health worries. A proportion of reported symptoms was ascribed to the placebo pill but not to the sham magnetic field. Symptom attributions were not related to any assessed psychological variables.

CONCLUSIONS

An aroused physiological state is not necessary for the automatic causal attribution process. Negative effects attributed to medication and environmental factors can be regarded as unavoidable side effects of human cognitive-emotional functioning; they might be alleviated, but cannot be completely eradicated.

The nocebo effect of drugs

While the placebo effect has been studied for a long time, much less is known about its negative counterpart, named the nocebo effect. However, it may be of particular importance because of its impact on the treatment outcomes and public health. We conducted a review on the nocebo effect using PubMed and other databases up to July 2014. The nocebo effect refers by definition to the induction or the worsening of symptoms induced by sham or active therapies. Examples are numerous and concerns both clinical trials and daily practice. The underlying mechanisms are, on one hand, psychological (conditioning and negative expectations) and, on the other hand, neurobiological (role of cholecystokinin, endogenous opioids and dopamine). Nocebo effects can modulate the outcome of a given therapy in a negative way, as do placebo effects in a positive way. The verbal and nonverbal communications of physicians contain numerous unintentional negative suggestions that may trigger a nocebo response. This raises the important issue of how physicians can at the same time obtain informed consent and minimize nocebo-related risks. Every physician has to deal with this apparent contradiction between primum non nocere and to deliver truthful information about risks. Meticulous identification of patients at risk, information techniques such as positive framing, contextualized informed consent, and even noninformation, is valuable.

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.

Does electromagnetic hypersensitivity originate from nocebo responses? Indications from a qualitative study

Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is a condition in which symptoms are attributed to electromagnetic field (EMF) exposure. As electro-hypersensitive (EHS) people have repeatedly been observed, during provocation trials, to report symptoms following perceived rather than actual exposure, the hypothesis has been put forward that IEI-EMF originates from psychological mechanisms, especially nocebo responses. This paper examines this hypothesis, using data from a qualitative study aimed at understanding how EHS people come to regard themselves as such. Forty self-diagnosed EHS people were interviewed. A typified model of their attribution process was then elaborated, inductively, from their narratives. This model is linear and composed of seven stages: (1) onset of symptoms; (2) failure to find a solution; (3) discovery of EHS; (4) gathering of information about EHS; (5) implicit appearance of conviction; (6) experimentation; (7) conscious acceptance of conviction. Overall, symptoms appear before subjects start questioning effects of EMF on their health, which is not consistent with the hypothesis that IEI-EMF originates from nocebo responses to perceived EMF exposure. However, such responses might occur at the sixth stage of the process, potentially reinforcing the attribution. It remains possible that some cases of IEI-EMF originate from other psychological mechanisms.

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

BACKGROUND

There is public concern about the potential health effects of exposure to extremely low frequency electromagnetic fields (ELF-EMF) of high-voltage power lines (HVPLs). Some residents living near HVPLs believe ELF-EMF might cause non-specific health complaints.

OBJECTIVES

The present study is the first to prospectively investigate whether self-reported health complaints and causal beliefs increase after the construction of a new power line.

METHODS

We used a quasi-experimental design with two pretests before and two posttests after a new HVPL was put into operation. Residents living near (0-300m, n=229; 300-500m, n=489) and farther away (500-2000m, n=536) participated in the study. Linear mixed models were fitted to test whether symptom reports and beliefs that power lines caused health complaints increased more in residents living close to the new line compared to residents living farther away.

RESULTS

A significantly (p<.05) larger increase from baseline in symptom reports and causal beliefs was found in residents living within 300m from the new power line when compared to residents living farther away. While symptom reports did not differ at baseline, the belief that a power line could cause these symptoms was at baseline already stronger for residents living close compared to residents living farther away.

CONCLUSIONS

We found a negative impact of a new HVPL on health perceptions of nearby residents, even before the line was put into operation.

Actual and perceived exposure to electromagnetic fields and non-specific physical symptoms: an epidemiological study based on self-reported data and electronic medical records

BACKGROUND

There is continuing scientific debate and increasing public concern regarding the possible effects of electromagnetic fields (EMF) on general population's health. To date, no epidemiological study has investigated the possible association between actual and perceived EMF exposure and non-specific physical symptoms (NSPS) and sleep quality, using both self-reported and general practice (GP)-registered data.

METHODS

A health survey of adult (≥ 18) participants (n=5933) in the Netherlands was combined with the electronic medical records (EMRs) of NSPS as registered by general practitioners. Characterization of actual exposure was based on several proxies, such as prediction models of radiofrequency (RF)-EMF exposure, geo-coded distance to high-voltage overhead power lines and self-reported use/distance of/to indoor electrical appliances. Perceived exposure and the role of psychological variables were also examined.

RESULTS

Perceived exposure had a poor correlation with the actual exposure estimates. No significant association was found between modeled RF-EMF exposure and the investigated outcomes. Associations with NSPS were observed for use of an electric blanket and close distance to an electric charger during sleep. Perceived exposure, perceived control and avoidance behavior were associated with the examined outcomes. The association between perceived exposure was stronger for self-reported than for GP-registered NSPS. There was some indication, but no consistent pattern for an interaction between idiopathic environmental intolerance (IEI-EMF) and the association between actual exposure and NSPS.

CONCLUSIONS

In conclusion, there is no convincing evidence for an association between everyday life RF-EMF exposure and NSPS and sleep quality in the population. Better exposure characterization, in particular with respect to sources of extremely low frequency magnetic fields (ELF-MF) is needed to draw more solid conclusions. We argue that perceived exposure is an independent determinant of NSPS.

Validity of the Greek version of the PHQ 15-item Somatic Symptom Severity Scale in patients with chronic medical conditions and correlations with emergency department use and illness perceptions

BACKGROUND

The PHQ-15 is a brief measure assessing the severity of somatic symptoms and is widely used in different health care settings. We aimed to assess the psychometric properties of its Greek version in patients with chronic physical illnesses seeking urgent or unscheduled care in the Accident and Emergency Department (AED).

METHODS

The PHQ-15 was translated into Greek using back-translation, and it was administered to 303 patients with diabetes, COPD and rheumatic diseases visiting our AED during a one-year period. Patients were interviewed with the MINI. Depressive (PHQ-9) and somatization symptoms (SCL-12), illness perceptions (B-IPQ) and health-related quality of life (WHOQOL-BREF) were also assessed to test criterion and concurrent validity.

RESULTS

The Greek version of the PHQ-15 showed acceptable internal consistency. Convergent validity was established by the strong associations observed between PHQ-15 scores and functional status, depressive symptom severity and AED visits during the previous year. PHQ-15 scores were also associated with the patients' concerns about personal and treatment illness's control and their beliefs regarding the number of bodily symptoms attributed to their illness (illness identity). The highly acceptable convergent and discriminant validity of the five individual bodily symptoms assessed by both the PHQ-15 and SCL-12 is a further construct validity indicator.

CONCLUSIONS

The present findings support the applicability of the Greek version of PHQ-15 in assessing common somatic symptoms either medically explained or unexplained in patients seeking care in the AED, further confirming that it can be considered suitable for use in a broad range of populations in clinical research.

Comparing non-specific physical symptoms in environmentally sensitive patients: prevalence, duration, functional status and illness behavior

OBJECTIVE

Little is known about the potential clinical relevance of non-specific physical symptoms (NSPS) reported by patients with self-reported environmental sensitivities. This study aimed to assess NSPS in people with general environmental sensitivity (GES) and idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) and to determine differences in functional status and illness behavior.

METHODS

An epidemiological study was conducted in the Netherlands, combining self-administered questionnaires with the electronic medical records of the respondents as registered by general practitioners. Analyses included n=5789 registered adult (≥18 years) patients, comprising 5073 non-sensitive (NS) individuals, 514 in the GES group and 202 in the IEI-EMF group.

RESULTS

Participants with GES were about twice as likely to consult alternative therapy compared to non-sensitive individuals; those with IEI-EMF were more than three times as likely. Moreover, there was a higher prevalence of symptoms and medication prescriptions and longer symptom duration among people with sensitivities. Increasing number and duration of self-reported NSPS were associated with functional impairment, illness behavior, negative symptom perceptions and prevalence of GP-registered NSPS in the examined groups.

CONCLUSION

Even after adjustment for medical and psychiatric morbidity, environmentally sensitive individuals experience poorer health, increased illness behavior and more severe NSPS. The number and duration of self-reported NSPS are important components of symptom severity and are associated with characteristics similar to those of NSPS in primary care. The substantial overlap between the sensitive groups strengthens the notion that different types of sensitivities might be part of one, broader environmental illness.

Health responses to a new high-voltage power line route: design of a quasi-experimental prospective field study in the Netherlands

Background

New high-voltage power transmission lines will be introduced due to increasing demand for reliable and renewable energy supplies. Some residents associate non-specific health complaints with exposure to electromagnetic fields from nearby power lines. This study protocol describes the design and rationale of a prospective study investigating whether the introduction of a new power line triggers health responses in residents living nearby.

Methods/Design

The study is designed as a quasi-experimental field study with two pretests during the construction of a new power line route, and two posttests after it has been put into operation. Key outcomes are self-reported non-specific somatic and cognitive health complaints, and attribution of these health complaints to a power line. The main determinant is proximity to the new power line route. One member of every household (n = 2379) residing in close proximity (0-500 meters) to the overhead parts of a new power line route in the Netherlands is invited to participate, as well as a sample of household members (n = 2382) residing farther away (500-2000 meters). Multilevel analysis will be employed to test whether an increase in key outcome measures is related to proximity to the line. Longitudinal structural equation models will be applied to test to what extent health responses are mediated by psychosocial health mechanisms and moderated by negative oriented personality traits.

Discussion

This is the first study to investigate health responses to a new power line route in a prospective manner. The results will provide theoretical insight into psychosocial mechanisms operating during the introduction of an environmental health risk, and may offer suggestions to policymakers and other stakeholders for minimizing adverse health responses when introducing new high-voltage power lines.

No effects of power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavior tests of workers inspecting transformers and distribution line stations versus controls

We aimed to evaluate the interference of 50 Hz extremely low frequency electromagnetic field (ELF-EMF) occupational exposure on the neurobehavior tests of workers performing tour-inspection close to transformers and distribution power lines. Occupational short-term "spot" measurements were carried out. 310 inspection workers and 300 logistics staff were selected as exposure and control. The neurobehavior tests were performed through computer-based neurobehavior evaluation system, including mental arithmetic, curve coincide, simple visual reaction time, visual retention, auditory digit span and pursuit aiming. In 500 kV areas electric field intensity at 71.98% of total measured 590 spots were above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.69% of total 701 spots were above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 μT (ICNIRP occupational standard). The neurobehavior score changes showed no statistical significance. Results of neurobehavior tests among different age, seniority groups showed no significant changes. Neurobehavior changes caused by daily repeated ELF-EMF exposure were not observed in the current study.