Personality, mental distress, and subjective health complaints among persons with environmental annoyance

Fear generalization and behavioral responses to multiple dangers

Animals often exhibit consistent-individual differences (CIDs) in boldness/fearfulness, typically studied in the context of predation risk. We focus here on fear generalization, where fear of one danger (e.g., predators) is correlated with fear of other dangers (e.g., humans, pathogens, moving vehicles, or fire). We discuss why fear generalization should be ecologically important, and why we expect fear to correlate across disparate dangers. CIDs in fear are well studied for some dangers in some taxa (e.g., human fear of pathogens), but not well studied for most dangers. Fear of some dangers has been found to correlate with general fearfulness, but some cases where we might expect correlated fears (e.g., between fear of humans, familiar predators, and exotic predators) are surprisingly understudied.

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.

Italian Expert Consensus on Clinical and Therapeutic Management of Multiple Chemical Sensitivity (MCS)

Multiple chemical sensitivity (MCS) is a multisystem, recurrent, environmental disorder that flares in response to different exposures (i.e., pesticides, solvents, toxic metals and molds) under the threshold limit value (TLV) calculated for age and gender in the general population. MCS is a syndrome characterized by cutaneous, allergic, gastrointestinal, rheumatological, endocrinological, cardiological and neurological signs and symptoms. We performed a systematic review of the literature to summarize the current clinical and therapeutic evidence and then oriented an eDelphi consensus. Four main research domains were identified (diagnosis, treatment, hospitalization and emergency) and discussed by 10 experts and an MCS patient. Thus, the first Italian MCS consensus had the double aim: (a) to improve MCS knowledge among healthcare workers and patients by standardizing the clinical and therapeutic management to MCS patients; and (b) to improve and shed light on MCS misconceptions not supported by evidence-based medicine (EBM).

Olfaction-Related Factors Affecting Chemosensory Dream Content in a Sleep Laboratory

Mental activity in sleep often involves visual and auditory content. Chemosensory (olfactory and gustatory) experiences are less common and underexplored. The aim of the study was to identify olfaction-related factors that may affect the occurrence of chemosensory dream content. Specifically, we investigated the effects of all-night exposure to an ambient odour, participants' appraisal of their current olfactory environment, their general propensity to notice odours and act on them (i.e., odour awareness), and their olfactory acuity. Sixty pre-screened healthy young adults underwent olfactory assessment, completed a measure of odour awareness, and spent three nights in weekly intervals in a sleep laboratory. The purpose of the first visit was to adapt to the experimental setting. On the second visit, half of them were exposed to the smell of vanillin or thioglycolic acid and the other half to an odourless control condition. On the third visit, they received control or stimulation in a balanced order. On each visit, data were collected twice: once from the first rapid eye movement (REM) stage that occurred after 3 a.m., and then shortly before getting up, usually from a non-REM stage. Participants were asked to report the presence of sensory dream content and to assess their current olfactory environment. Neither exposure, nor participants' assessments of the ambient odour, or olfactory acuity affected reports of chemosensory dream content but they were more frequent in individuals with greater odour awareness. This finding may have implications for treatment when such experiences become unwanted or bothersome.

One Single Question Is not Sufficient to Identify Individuals With Electromagnetic Hypersensitivity

Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is a self-reported condition where non-specific symptoms are attributed to weak non-ionizing electromagnetic fields. Despite its expanding prevalence, there is no generally accepted diagnostic procedure or definition to identify patients with this condition, thus studies usually apply only one question as inclusion criterion. The aim of our study was to demonstrate the heterogeneity of a self-reported IEI-EMF group and to identify further self-report questions that could be applied as inclusion criteria.

Cross-sectional on-line survey study was carried out with 473 participants (76.3% women; age: 35.03 ± 13.24 yrs). Self-diagnosed IEI-EMF (as assessed with a yes-or-no question), frequency of EMF-related symptom and severity of the condition were assessed, as well as somatic symptom distress (Patient Health Questionnaire Somatic Symptom Severity Scale, PHQ-15).

72 (15.2%) individuals labelled themselves as IEI-EMF, however only 61% of them remained in the IEI-EMF group after the use of three inclusion criteria instead of one. 21% of the individuals labelling themselves as IEI-EMF reported neither symptoms nor any negative impact on their daily life.

A minimum of two questions appear to be necessary as inclusion criteria for IEI-EMF in empirical research. Instead of the widely used yes-or-no question on accepting the IEI-EMF label, occurrence of symptoms attributed to EMF on a regular basis and at least a slight negative impact on daily life are required.

Electromagnetic hypersensitivity (IEI-EMF) is often assessed by one yes-or-no self-report question.

This practice is inappropriate from a conceptual and methodological point of view.

At least two questions, assessing frequency of symptoms and their impact, are needed.

Multiple Chemical Sensitivity: Review of the State of the Art in Epidemiology, Diagnosis, and Future Perspectives

OBJECTIVE

Systematic bibliography analysis of about the last 17 years on multiple chemical sensitivity (MCS) was carried out in order to detect new diagnostic and epidemiological evidence. The MCS is a complex syndrome that manifests as a result of exposure to a low level of various common contaminants. The etiology, diagnosis, and treatment are still debated among researchers.

METHOD

Querying PubMed, Web of Science, Scopus, Cochrane library, both using some specific MESH terms combined with MESH subheadings and through free search, even by Google.

RESULTS

The studies were analyzed by verifying 1) the typology of study design; 2) criteria for case definition; 3) presence of attendances in the emergency departments and hospital admissions, and 4) analysis of the risk factors.

OUTLOOK

With this review, we give some general considerations and hypothesis for possible future research.

Health-related quality among life of employees with persistent nonspecific indoor-air-associated health complaints

OBJECTIVE

Nonspecific health complaints associated with indoor air are common in work environments. In some individuals, symptoms become persistent without an adequate explanation. The aim was to study factors that associate with the health-related quality of life (HRQoL) of employees with persistent, nonspecific indoor-air-related symptomatology.

METHODS

We present baseline results of a randomized controlled trial of interventions targeted on the HRQoL of the employees with indoor-air-associated nonspecific symptoms. The main participant-inclusion criterion was the presence of persistent indoor-air-related multiorgan symptoms with no known pathophysiological or environment-related explanation. As a comparison for participants´ HRQoL (n = 52) we used data from the general-population Health 2011 study (BRIF8901) including information on subjects matched to the participants´ working status and age and subjects with asthma, anxiety or depressive disorder, or other chronic conditions with work disability.

RESULTS

The participants showed greater and a clinically significant impairment of HRQoL [M = 0.83, SE = 0.013] than individuals from the general population [M = 0.95, SE = 0.001, p < .001, Hedges´ g = 2.33] and those with asthma [M = 0.93, SE = 0.005, p < .001, Hedges´ g = 1.46], anxiety and depressive disorder [M = 0.89, SE = 0.006, p < .001, Hedges´ g = 0.73], or a chronic condition with work disability [M = 0.91, SE = 0.003, p < .001, Hedges´ g = 1.11]. Prevalent symptoms of depression, anxiety, and insomnia and poor recovery from work were associated with a poor HRQoL.

CONCLUSIONS

Individuals with nonspecific indoor-air-associated symptoms have a poorer HRQoL than individuals in the general population with a globally burdensome disease. Psychological distress associated with a poor HRQoL should be considered in the making of decisions about the treatment of these patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02069002.

Psychological symptoms and health-related quality of life in idiopathic environmental intolerance attributed to electromagnetic fields

OBJECTIVE

Need for better understanding of the etiology of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) motivated the present study of psychological symptoms and health-related quality of life (HRQoL) in person who attribute health problems to electromagnetic fields.

METHODS

Participants with IEI-EMF (n=114) and a population-based sample of referents (n=104) were investigated with six subscales of the Symptom Checklist 90 (SCL-90) to assess psychological symptoms, and with eight subscales of the Short Form (36) Health Survey (SF-36) to assess HRQoL.

RESULTS

Significantly higher scores were found on obsessive/compulsive behavior, interpersonal hypersensitivity, hostility, phobic anxiety, paranoid thoughts in the IEI-EMF group compared to referents, whereas only a tendency of such a difference was found for psychotism. Furthermore, poorer HRQoL in the IEI-EMF group, compared to referents, were found regarding physical and social functioning, physical and emotional role limitations, general health, vitality, bodily pain, and mental health. Significant correlation with moderate to strong effect sizes were found between several of the SCL-90 and SF-36 subscales.

CONCLUSION

The results suggest that IEI-EMF is associated with various types of psychological symptoms and with poor HRQoL. Clinical implications include theoretical support for cognitive behavioral therapy, and, although further research is needed, that attention should be directed towards feelings of inferiority and uneasiness in relationships as well as anger, hostility and resentment towards other people.

Noise sensitivity and future risk of illness and mortality

Aircraft and road traffic noise exposure increase the risk of cardiovascular disease (CVD). Noise annoyance is the most frequent response to environmental noise. Noise annoyance has been shown to modify the association of transport noise exposure on CVD and noise sensitivity moderates the annoyance response to noise. This study uses prospective data from phases 1, 3, 5, 7 and 9 in 3630 male and female civil servants from the UK Whitehall II Study to examine whether a single question on noise sensitivity measured by annoyance responses to noise in general predicts physical and mental ill-health and mortality. Non-fatal myocardial infarction and stroke morbidity over the follow-up were defined by MONICA criteria based on study ECGs, hospital records, hospital admission statistics or General Practitioner confirmation. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale (CES-D) and psychological distress by the General Health questionnaire (GHQ). There was no association between noise sensitivity and CVD morbidity or mortality except in people from lower employment grades where there was an association with angina. Noise sensitivity was a consistent predictor of depressive symptoms and psychological distress at phases 3, 5 and 7. High noise sensitivity scores at baseline predicted GHQ caseness at phase 3 adjusting for age, sex, employment grade, self-rated health and GHQ caseness at baseline (OR=1.56 95% CI 1.29-1.88). Noise sensitivity has been identified as a predictor of mental ill-health. More longitudinal research is needed including measures of noise exposure.

Negative affect is associated with development and persistence of chemical intolerance: a prospective population-based study

OBJECTIVE

Chemical intolerance (CI) is characterised by negative health effects attributed to a heightened responsiveness to common airborne chemicals. This longitudinal study explored the hypothesised role of negative affect in the development and persistence of CI in a general population.

METHODS

A general population sample aged 19 to 72 years was examined in 2006-2008 and again in 2011-2012. Longitudinal data on CI were analysed with the purpose of examining baseline negative affect as a risk factor for having developed CI at 5-year follow-up and for reporting persistent CI. Participants were classified as reporting no signs of CI, having symptoms of CI and as being a likely CI case based on self-reported reactions to 11 common chemical exposures, symptoms related to chemical exposures and daily life adjustments attributed to reactions when exposed to chemicals.

RESULTS

A total of 69.4% of the participants who had reported CI at baseline also reported CI at follow-up. In participants with no baseline CI, 15.5% reported CI at follow-up and 18.1% reported symptoms related to chemicals but no daily life adjustments. Baseline negative affect was positively and statistically significantly associated with both development and persistence of CI.

CONCLUSIONS

Initial reports of CI were found to be persistent over time, and a considerable proportion of the participants with no CI at baseline reported having developed CI after 5 years. The positive association between negative affect and CI at the 5-year follow-up supports negative affect as a possible risk factor for CI.

Odor and noise intolerance in persons with self-reported electromagnetic hypersensitivity

Lack of confirmation of symptoms attributed to electromagnetic fields (EMF) and triggered by EMF exposure has highlighted the role of individual factors. Prior observations indicate intolerance to other types of environmental exposures among persons with electromagnetic hypersensitivity (EHS). This study assessed differences in odor and noise intolerance between persons with EHS and healthy controls by use of subscales and global measures of the Chemical Sensitivity Scale (CSS) and the Noise Sensitivity Scale (NSS). The EHS group scored significantly higher than the controls on all CSS and NSS scales. Correlation coefficients between CSS and NSS scores ranged from 0.60 to 0.65 across measures. The findings suggest an association between EHS and odor and noise intolerance, encouraging further investigation of individual factors for understanding EMF-related symptoms.

Metabolic and genetic screening of electromagnetic hypersensitive subjects as a feasible tool for diagnostics and intervention

Growing numbers of "electromagnetic hypersensitive" (EHS) people worldwide self-report severely disabling, multiorgan, non-specific symptoms when exposed to low-dose electromagnetic radiations, often associated with symptoms of multiple chemical sensitivity (MCS) and/or other environmental "sensitivity-related illnesses" (SRI). This cluster of chronic inflammatory disorders still lacks validated pathogenetic mechanism, diagnostic biomarkers, and management guidelines. We hypothesized that SRI, not being merely psychogenic, may share organic determinants of impaired detoxification of common physic-chemical stressors. Based on our previous MCS studies, we tested a panel of 12 metabolic blood redox-related parameters and of selected drug-metabolizing-enzyme gene polymorphisms, on 153 EHS, 147 MCS, and 132 control Italians, confirming MCS altered (P < 0.05-0.0001) glutathione-(GSH), GSH-peroxidase/S-transferase, and catalase erythrocyte activities. We first described comparable-though milder-metabolic pro-oxidant/proinflammatory alterations in EHS with distinctively increased plasma coenzyme-Q10 oxidation ratio. Severe depletion of erythrocyte membrane polyunsaturated fatty acids with increased ω 6/ ω 3 ratio was confirmed in MCS, but not in EHS. We also identified significantly (P = 0.003) altered distribution-versus-control of the CYP2C19∗1/∗2 SNP variants in EHS, and a 9.7-fold increased risk (OR: 95% C.I. = 1.3-74.5) of developing EHS for the haplotype (null)GSTT1 + (null)GSTM1 variants. Altogether, results on MCS and EHS strengthen our proposal to adopt this blood metabolic/genetic biomarkers' panel as suitable diagnostic tool for SRI.

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.

Risks perception of electromagnetic fields in Taiwan: the influence of psychopathology and the degree of sensitivity to electromagnetic fields

Little is known about the perceived health risks of electromagnetic fields (EMFs) and factors associated with risk perception in non-Western countries. Psychological conditions and risk perception have been postulated as factors that facilitate the attribution of health complaints to environmental factors. This study investigated people's perceived risks of EMFs and other environmental sources, as well as the relationships between risk perception, psychopathology, and the degree of self-reported sensitivity to EMFs. A total of 1,251 adults selected from a nationwide telephone interviewing system database responded to a telephone survey about the relationships between environmental sources and human health. The interview included questions assessing participants' psychiatric conditions and the presence and degree of sensitivity to EMFs. One hundred and seventy participants were self-identified as having sensitivity to EMFs, and 141 met the criteria for psychiatric conditions without EMF sensitivity. More than half of the survey respondents considered power lines and mobile phone base stations to affect people's health to a big extent. Higher sensitivity to EMFs, psychopathology, being female, being married, more years of education, and having a catastrophic illness had positive associations with perceived risks of EMF-related environmental sources as well as for all environmental sources combined. We observed no moderating effect of psychopathology on the association between degree of sensitivity to EMF and risk perception. Thus, psychopathology had influence on general people's risk perception without having influence on the relationship between people's degree of sensitivity to EMF and risk perception. The plausible explanations are discussed in the text.

Design of an ecological momentary assessment study of exposure to radiofrequency electromagnetic fields and non-specific physical symptoms

INTRODUCTION

Idiopathic Environmental Intolerance (IEI) attributed to electromagnetic fields (EMF) refers to self-reported sensitivity mainly characterised by the attribution of non-specific physical symptoms to low-level EMF exposure emitted from sources such as mobile phones. Scientific studies have not provided evidence for the existence of IEI-EMF, but these studies did not resemble the real-life situation or suffered from poor exposure characterisation and biased recall of health symptoms. To improve existing methods for the study of IEI-EMF, an Ecological Momentary Assessment (EMA) study is designed.

METHODS AND ANALYSIS

The study is an EMA study in which respondents carry personal exposure metres (exposimeters) that measure radiofrequency (RF) EMF, with frequent assessment of health symptoms and perceived EMF exposure through electronic diary registration during five consecutive days. Participants will be a selection from an epidemiological study who report to be sensitive to RF EMF. The exposimeters measure electric field strength in 12 frequency bands. Diary questions include the occurrence and severity of 10 non-specific physical symptoms, mood states and perceived exposure to (sources of) EMF. The relationship of actual and perceived EMF exposure and mood with non-specific physical symptoms will be analysed using multilevel regression analysis with time-shift models.

DISCUSSION

The study has several advantages over previous studies, including assessment of personal EMF exposure and non-specific physical symptoms by an ecological method with a minimised chance of recall bias. The within-person design reduces confounding by time-stable factors (eg, personal characteristics). In the conduct of the study and the analysis and interpretation of its outcomes, some methodological issues including a high participant burden, reactivity, compliance to the study protocol and the potential of chance findings due to multiple statistical testing will be accounted for and limited as much as possible.

Transcranial pulsed electromagnetic fields for multiple chemical sensitivity: study protocol for a randomized, double-blind, placebo-controlled trial

Background

Multiple chemical sensitivity (MCS) is a chronic condition of unknown etiology. MCS is characterized by recurrent nonspecific symptoms from multiple organ systems in response to chemical exposures in concentrations that are normally tolerated by the majority of the population. The symptoms may have severe impact on patients’ lives, but an evidence-based treatment for the condition is nonexisting. The pathophysiology is unclarified, but several indicators point towards abnormal processing of sensory signals in the central nervous system. Pulsed electromagnetic fields (PEMF) offer a promising new treatment for refractory depression and can be targeted at the brain, thereby activating biochemical cell processes.

Methods/Design

In a parallel, randomized, double-blind, placebo-controlled trial conducted at the Danish Research Centre for Chemical Sensitivities, the effects of PEMF in MCS patients will be assessed using the Re5 Independent System. Based on sample size estimation, 40 participants will be randomized to either PEMF therapy or placebo. The allocation sequence will be generated by computer. All involved parties (that is, participants, investigators, the research nurse, and the statistician) will be blinded to group allocation. The participants will receive PEMF therapy or placebo applied transcranially 30 minutes twice a day for 7 days a week over 6 consecutive weeks. Outcomes will be measured at baseline, once weekly during treatment, post treatment, and at 2.5-month and 4.5-month follow-up according to a predefined timetable. The primary outcome will be a measurement of the impact of MCS on everyday life. The secondary outcomes will be measurements of MCS symptoms, psychological distress (stress, anxiety or depressive symptoms), capsaicin-induced secondary punctate hyperalgesia, immunological markers in serum, and quality of life.

Discussion

This trial will assess the effects of PEMF therapy for MCS. Currently, there is no treatment with a documented effect on MCS, and in terms of healthcare there is very little to offer these patients. There is thus a great need for well-conducted randomized trials aimed at assessing possible treatment effects. A positive outcome will pave the way for improved healthcare and understanding of this very disabling and overlooked condition.

Trial registration

ClinicalTrials.gov, NCT01834781

Women with multiple chemical sensitivity have increased harm avoidance and reduced 5-HT(1A) receptor binding potential in the anterior cingulate and amygdala

Multiple chemical sensitivity (MCS) is a common condition, characterized by somatic distress upon exposure to odors. As in other idiopathic environmental intolerances, the underlying mechanisms are unknown. Contrary to the expectations it was recently found that persons with MCS activate the odor-processing brain regions less than controls, while their activation of the anterior cingulate cortex (ACC) is increased. The present follow-up study was designed to test the hypotheses that MCS subjects have increased harm avoidance and deviations in the serotonin system, which could render them intolerant to environmental odors. Twelve MCS and 11 control subjects, age 22–44, all working or studying females, were included in a PET study where 5-HT_1A receptor binding potential (BP) was assessed after bolus injection of [¹¹C]WAY100635. Psychological profiles were assessed by the Temperament and Character Inventory and the Swedish universities Scales of Personality. All MCS and 12 control subjects were also tested for emotional startle modulation in an acoustic startle test. MCS subjects exhibited significantly increased harm avoidance, and anxiety compared to controls. They also had a reduced 5-HT_1A receptor BP in amygdala (p = 0.029), ACC (p = 0.005) (planned comparisons, significance level 0.05), and insular cortex (p = 0.003; significance level p<0.005 with Bonferroni correction), and showed an inverse correlation between degree of anxiety and the BP in the amygdala (planned comparison). No group by emotional category difference was found in the startle test. Increased harm avoidance and the observed changes in the 5-HT_1A receptor BP in the regions processing harm avoidance provides a plausible pathophysiological ground for the symptoms described in MCS, and yields valuable information for our general understanding of idiopathic environmental intolerances.

Distribution of subjective health complaints, and their association with register based sickness absence in the Danish working population

AIMS

To describe the distribution of subjective health complaints (SHCs) in a Danish working population and the associations between SHC and register based sickness absence.

METHODS

The study entailed 2876 men and 3574 women aged 18-59 years that constituted the 2005 panel in the Danish Work Environment Cohort Study (DWECS). All had completed a subjective health complaints inventory and the Nordic Musculoskeletal Questionnaire (NMQ). Seven SHC/NMQ indices were constructed and merged with subsequently collected data on prolonged sickness absence periods (each period > 14 days) that was registered in the national Danish register on social transfer payments: the DREAM register. Ordinal logistic regression was used to model the cumulative odds for sickness absence as a function of strata.

RESULTS

The majority of participants reported at least one SHC during a 30-day period (circa 89% of the men and 95% of the women). The reports of severe SHC, defined as recurring SHC within the 30-day period, were less common. About 55% of the men and 68% of the women reported at least one severe SHC during a 30-day period. The odds ratios of sickness absence increased with the number of SHC a participant acknowledged. The odds ratios were slightly reduced after adjusting for age, disease history and social class.

CONCLUSIONS

The majority of the working population in Denmark report at least one SHC during a 30-day period. Roughly half of the population report having at least one recurrent (often to very often) SHC during the last 30-days (severe SHC). Reporting the presence of several SHCs increases the likelihood of having more prospectively registered periods of sickness absence above two weeks.

Indoor air pollutants in office environments: assessment of comfort, health, and performance

Concentrations of volatile organic compounds (VOCs) in office environments are generally too low to cause sensory irritation in the eyes and airways on the basis of estimated thresholds for sensory irritation. Furthermore, effects in the lungs, e.g. inflammatory effects, have not been substantiated at indoor relevant concentrations. Some VOCs, including formaldehyde, in combination may under certain environmental and occupational conditions result in reported sensory irritation. The odour thresholds of several VOCs are low enough to influence the perceived air quality that result in a number of acute effects from reported sensory irritation in eyes and airways and deterioration of performance. The odour perception (air quality) depends on a number of factors that may influence the odour impact. There is neither clear indication that office dust particles may cause sensory effects, even not particles spiked with glucans, aldehydes or phthalates, nor lung effects; some inflammatory effects may be observed among asthmatics. Ozone-initiated terpene reaction products may be of concern in ozone-enriched environments (≥0.1mg/m(3)) and elevated limonene concentrations, partly due to the production of formaldehyde. Ambient particles may cause cardio-pulmonary effects, especially in susceptible people (e.g. elderly and sick people); even, short-term effects, e.g. from traffic emission and candle smoke may possibly have modulating and delayed effects on the heart, but otherwise adverse effects in the airways and lung functions have not been observed. Secondary organic aerosols generated in indoor ozone-initiated terpene reactions appear not to cause adverse effects in the airways; rather the gaseous products are relevant. Combined exposure to particles and ozone may evoke effects in subgroups of asthmatics. Based on an analysis of thresholds for odour and sensory irritation selected compounds are recommended for measurements to assess the indoor air quality and to minimize reports of irritation symptoms, deteriorated performance, and cardiovascular and pulmonary effects.

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF): a systematic review of identifying criteria

BACKGROUND

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) remains a complex and unclear phenomenon, often characterized by the report of various, non-specific physical symptoms (NSPS) when an EMF source is present or perceived by the individual. The lack of validated criteria for defining and assessing IEI-EMF affects the quality of the relevant research, hindering not only the comparison or integration of study findings, but also the identification and management of patients by health care providers. The objective of this review was to evaluate and summarize the criteria that previous studies employed to identify IEI-EMF participants.

METHODS

An extensive literature search was performed for studies published up to June 2011. We searched EMBASE, Medline, Psychinfo, Scopus and Web of Science. Additionally, citation analyses were performed for key papers, reference sections of relevant papers were searched, conference proceedings were examined and a literature database held by the Mobile Phones Research Unit of King's College London was reviewed.

RESULTS

Sixty-three studies were included. "Hypersensitivity to EMF" was the most frequently used descriptive term. Despite heterogeneity, the criteria predominantly used to identify IEI-EMF individuals were: 1. Self-report of being (hyper)sensitive to EMF. 2. Attribution of NSPS to at least one EMF source. 3. Absence of medical or psychiatric/psychological disorder capable of accounting for these symptoms 4. Symptoms should occur soon (up to 24 hours) after the individual perceives an exposure source or exposed area. (Hyper)sensitivity to EMF was either generalized (attribution to various EMF sources) or source-specific. Experimental studies used a larger number of criteria than those of observational design and performed more frequently a medical examination or interview as prerequisite for inclusion.

CONCLUSIONS

Considerable heterogeneity exists in the criteria used by the researchers to identify IEI-EMF, due to explicit differences in their conceptual frameworks. Further work is required to produce consensus criteria not only for research purposes but also for use in clinical practice. This could be achieved by the development of an international protocol enabling a clearly defined case definition for IEI-EMF and a validated screening tool, with active involvement of medical practitioners.

Non-specific physical symptoms and electromagnetic field exposure in the general population: can we get more specific? A systematic review

OBJECTIVE

A systematic review of observational studies was performed to address the strength of evidence for an association between actual and perceived exposure to electromagnetic fields (EMF) and non-specific physical symptoms (NSPS) in the general population. To gain more insight into the magnitude of a possible association, meta-analyses were conducted.

METHODS

Literature databases Medline, Embase, SciSearch, PsychInfo, Psyndex and Biosis and additional bibliographic sources such as reference sections of key publications were searched for the detection of studies published between January 2000 and April 2011.

RESULTS

Twenty-two studies met our inclusion criteria. Qualitative assessment of the epidemiological evidence showed either no association between symptoms and higher EMF exposure or contradictory results. To strengthen our conclusions, random effects meta-analyses were performed, which produced the following results for the association with actual EMF; for symptom severity: Headache odds ratio (OR)=1.65; 95% confidence interval (CI)=0.88-3.08, concentration problems OR=1.28; 95% CI=0.56-2.94, fatigue-related problems OR=1.15; 95% CI=0.59-2.27, dizziness-related problems OR=1.38; 95% CI=0.92-2.07. For symptom frequency: headache OR=1.01; 95% CI=0.66-1.53, fatigue OR=1.12; 95% CI=0.60-2.07 and sleep problems OR=1.18; 95% CI=0.80-1.74. Associations between perceived exposure and NSPS were more consistently observed but a meta-analysis was not performed due to considerable heterogeneity between the studies.

CONCLUSIONS

This systematic review and meta-analysis finds no evidence for a direct association between frequency and severity of NSPS and higher levels of EMF exposure. An association with perceived exposure seems to exist, but evidence is still limited because of differences in conceptualization and assessment methods.

Evaluation of the quick environmental exposure and sensitivity inventory in a Danish population

Objectives. To evaluate a Danish translation of the Quick Environmental Exposure and Sensitivity Inventory (QEESI). Methods. The study included two groups: one comprised a random sample of 2000 individuals drawn from the Danish Civil Registration System; the other comprised 315 patients with chemical intolerance. Results. The evaluation suggested good reliability for the four QEESI scales in terms of internal consistency and coefficients between test and retest scores. The discriminatory validity was the largest for the Chemical (inhalant) Intolerance and Life Impact Scales. Using combined cut-off scores for these two scales provided a sensitivity of 92.1 and a specificity of 91.8 and yielded a prevalence of 8.2% in the population group. Conclusions. The Danish translation of the QEESI showed overall good reliability and validity. We recommend the use of the combined Chemical (inhalant) Intolerance and Life Impact Scales in future studies.

Do people with idiopathic environmental intolerance attributed to electromagnetic fields display physiological effects when exposed to electromagnetic fields? A systematic review of provocation studies

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) is a controversial illness in which people report symptoms that they believe are triggered by exposure to EMF. Double-blind experiments have found no association between the presence of EMF and self-reported outcomes in people with IEI-EMF. No systematic review has assessed whether EMF exposure triggers physiological or cognitive changes in this group. Using a systematic literature search, we identified 29 single or double-blind experiments in which participants with IEI-EMF were exposed to different EMF levels and in which objectively measured outcomes were assessed. Five studies identified significant effects of exposure such as reduced heart rate and blood pressure, altered pupillary light reflex, reduced visual attention and perception, improved spatial memory, movement away from an EMF source during sleep and altered EEG during sleep. In most cases, these were isolated results that other studies failed to replicate. For the sleep EEG findings, the results reflected similar changes in the IEI-EMF participants and a non-IEI-EMF control group. At present, there is no reliable evidence to suggest that people with IEI-EMF experience unusual physiological reactions as a result of exposure to EMF. This supports suggestions that EMF is not the main cause of their ill health.

Non-specific physical symptoms in relation to actual and perceived proximity to mobile phone base stations and powerlines

Background

Evidence about a possible causal relationship between non-specific physical symptoms (NSPS) and exposure to electromagnetic fields (EMF) emitted by sources such as mobile phone base stations (BS) and powerlines is insufficient. So far little epidemiological research has been published on the contribution of psychological components to the occurrence of EMF-related NSPS. The prior objective of the current study is to explore the relative importance of actual and perceived proximity to base stations and psychological components as determinants of NSPS, adjusting for demographic, residency and area characteristics.

Methods

Analysis was performed on data obtained in a cross-sectional study on environment and health in 2006 in the Netherlands. In the current study, 3611 adult respondents (response rate: 37%) in twenty-two Dutch residential areas completed a questionnaire. Self-reported instruments included a symptom checklist and assessment of environmental and psychological characteristics. The computation of the distance between household addresses and location of base stations and powerlines was based on geo-coding. Multilevel regression models were used to test the hypotheses regarding the determinants related to the occurrence of NSPS.

Results

After adjustment for demographic and residential characteristics, analyses yielded a number of statistically significant associations: Increased report of NSPS was predominantly predicted by higher levels of self-reported environmental sensitivity; perceived proximity to base stations and powerlines, lower perceived control and increased avoidance (coping) behavior were also associated with NSPS. A trend towards a moderator effect of perceived environmental sensitivity on the relation between perceived proximity to BS and NSPS was verified (p = 0.055). There was no significant association between symptom occurrence and actual distance to BS or powerlines.

Conclusions

Perceived proximity to BS, psychological components and socio-demographic characteristics are associated with the report of symptomatology. Actual distance to the EMF source did not show up as determinant of NSPS.

Cortisol variability and self-reports in the measurement of work-related stress

We examined whether a high cortisol awakening response (CAR) and low cortisol decline over the day (CDD) are related to self-reported work stress and well-being, and whether there are gender differences in these relationships. Three hundred eighty-three working men and women responded to a survey measuring job stress factors, mastery at work, symptoms and well-being. Salivary cortisol was sampled at awakening, after 45 min and at 21:00, from which the variables CAR and CDD were defined. A high CAR was associated with lower perceived job control and work mastery, and poorer well-being. Low CDD was associated only with higher job demands, but the self-report scores showed a number of interactions between cortisol group and gender. Among women, those showing a low CDD, compared with those with a higher CDD, had more favourable scores on a number of job stress factors and symptom load. In contrast, among men, a similar comparison showed those with low CDD to have poorer scores on job stress factors and symptom load. We conclude that individuals displaying high CAR or low CDD differ from those not displaying these cortisol profiles in self-report of work stress and well-being, and that gender differences appear in these relationships.

The association between idiopathic environmental intolerance and psychological distress, and the influence of social support and recent major life events

OBJECTIVES

Idiopathic environmental intolerance (IEI) is a disorder characterized by non-specific symptoms attributed to common airborne chemicals. Increasing evidence points to an association between IEI and symptoms of psychological distress. However, whether other risk factors influence this association has not been clarified. The objective of this study was to examine the association between psychological distress and IEI and to determine whether the association is confounded by social support and major life events.

METHODS

Data were collected by postal questionnaires; other results from the study have been published previously in this journal. The study included participants from a general population-based study who had reported symptoms of chemical sensitivities (n = 787) and two patient groups. The first patient group (n = 101) included individuals who had contacted the Danish Research Centre for Chemical Sensitivities, and the second included individuals who had been diagnosed with environmental intolerance (n = 136). Multiple, hierarchical linear regression analyses were conducted with four IEI-related domains, i.e., mucosal and CNS symptoms, chemical intolerances and social consequences, as the dependent variables, and psychological distress, social support and major life events as the independent variables.

RESULTS

Our study confirmed positive and statistically significant associations between psychological distress and IEI. The associations remained statistically significant after adjusting for major life events and social support.

CONCLUSIONS

The results suggest that the association between IEI and psychological distress cannot be explained by known risk factors. More studies, including longitudinal studies, are needed to determine the role of psychological distress in the development and course of IEI.

The airway sensory hyperreactivity syndrome

After exclusion of diverse pulmonary illnesses, the remaining explanations for chronic cough include medication with angiotensin-converting enzyme (ACE) inhibitor, gastroesophageal reflux disease (GERD), and post-nasal drip. Different clinics report shifting frequencies for both the causes of chronic cough and the success of treatment. However, after all evaluations, differential diagnosis still leaves a group of patients with unexplained cough. This unexplained cough is also known as chronic idiopathic cough (CIC), though there are widely varying opinions as to its existence. Among patients previously diagnosed with CIC, a subgroup has been identified with both upper and lower airway symptoms, including cough induced by odours and chemicals, and with increased cough sensitivity to inhaled capsaicin, which is known to stimulate the airway sensory nerves. A suggested explanation for this condition is a hyperreactivity of the sensory nerves of the entire airways, and hence the condition is known as sensory hyperreactivity (SHR). SHR affects more than 6% of the adult population in Sweden. It is a longstanding condition, and is clearly associated with significant social and psychological impacts.

Factors associated with prospective development of environmental annoyance

OBJECTIVES

Idiopathic environmental intolerance (IEI) has in cross-sectional studies been associated with emotional problems and psychiatric disorders. However, in the absence of prospective studies it has not been possible to determine whether emotional problems precede the onset of IEI, or are a consequence of IEI. The purpose of this study was to address this issue in a prospective panel study design.

METHODS

The study sample (n=10 275) responded to a postal survey that included five questions regarding annoyance from environmental factors, at baseline and at follow-up five years later. Associations between a number of self-rating scales of stress, subjective health, and working conditions at baseline on one hand, and development of environmental annoyance from baseline to follow-up on the other, were examined.

RESULTS

Participants having developed environmental annoyance between baseline and follow-up had at baseline reported more subjective health complaints, higher levels of stress, strain, and lack of recovery, more dissatisfaction with their work situation, and lower personal social support, compared to participants not developing environmental annoyance.

CONCLUSION

Elevated subjective health complaints, high stress in daily life and a strained work situation, all possible signs of sustained arousal, increase the risk of developing annoyance to environmental factors. The results fit the hypothesis that reduced subjective health, over the course of time, may be attributed to environmental factors.

Repressive coping and alexithymia in idiopathic environmental intolerance

OBJECTIVE

To examine if the non-expression of negative emotions (i.e., repressive coping) and differences in the ability to process and regulate emotions (i.e., alexithymia) is associated with idiopathic environmental intolerance (IEI).

METHODS

The study included participants who had previously participated in a general population-based study and reported symptoms of environmental intolerance (n = 787) and patients with IEI (n = 237). The participants completed questionnaires assessing IEI, namely, a measure of repressive coping combining scores on the Marlowe-Crowne Social Desirability Scale (MCSDS) and the Taylor Manifest Anxiety Scale (TMAS), the Toronto Alexithymia Scale (TAS-20), and a negative affectivity scale (NAS). Multiple, hierarchical linear regression analyses were conducted using IEI variables as the dependent variables.

RESULTS

The TMAS and MCSDS scores were independently associated with the IEI variables, but there was no evidence of a role of the repressive coping construct. While the total alexithymia score was unrelated to IEI, the TAS-20 subscale of difficulties identifying feelings (DIF) was independently associated with symptoms attributed to IEI. Negative affectivity was a strong independent predictor of the IEI variables and a mediator of the association between DIF and IEI.

CONCLUSION

Our results provide no evidence for a role of repressive coping in IEI, and our hypothesis of an association with alexithymia was only partly supported. In contrast, strong associations between IEI and negative emotional reactions, defensiveness and difficulties identifying feelings were found, suggesting a need for exploring the influence of these emotional reactions in IEI.

Symptoms, personality traits, and stress in people with mobile phone-related symptoms and electromagnetic hypersensitivity

OBJECTIVE

Some people report symptoms that they associate with electromagnetic field (EMF) exposure. These symptoms may be related to specific EMF sources or to electrical equipment in general (perceived electromagnetic hypersensitivity, EHS). Research and clinical observations suggest a difference between mobile phone (MP)-related symptoms and EHS with respect to symptom prevalence, psychological factors, and health prognosis. This study assessed prevalence of EMF-related and EMF-nonrelated symptoms, anxiety, depression, somatization, exhaustion, and stress in people with MP-related symptoms or EHS versus a population-based sample and a control sample without EMF-related symptoms.

METHODS

Forty-five participants with MP-related symptoms and 71 with EHS were compared with a population-based sample (n=106) and a control group (n=63) using self-report questionnaires.

RESULTS

The EHS group reported more symptoms than the MP group, both EMF-related and EMF-nonrelated. The MP group reported a high prevalence of somatosensory symptoms, whereas the EHS group reported more neurasthenic symptoms. As to self-reported personality traits and stress, the case groups differed only on somatization and listlessness in a direct comparison. In comparison with the reference groups, the MP group showed increased levels of exhaustion and depression but not of anxiety, somatization, and stress; the EHS group showed increased levels for all of the conditions except for stress.

CONCLUSION

The findings support the idea of a difference between people with symptoms related to specific EMF sources and people with general EHS with respect to symptoms and anxiety, depression, somatization, exhaustion, and stress. The differences are likely to be important in the management of patients.

Attention to bodily sensations and symptom perception in individuals with idiopathic environmental intolerance

INTRODUCTION

Idiopathic environmental intolerance (IEI) is characterized by non-specific symptoms attributed to exposure to environmental odours or chemicals at levels below those known to induce adverse health effects. A clarification of whether psychological processes involved in sensory perceptions are associated with IEI would add to our understanding of this complex disorder.

PURPOSE

To examine if measures of somato-sensory amplification, autonomic perception and absorption are associated with IEI.

METHODS

The study included individuals with self-reported or physician-diagnosed IEI. Participants (n = 732) completed questionnaires that included items on descriptive variables of IEI, the Somato-Sensory Amplification Scale (SSAS), the Autonomic Perception Questionnaire (APQ), the Tellegen Absorption Scale (TAS) and a Negative Affectivity Scale (NAS).

RESULTS

Multiple, hierarchical linear regression analyses revealed significant positive associations between SSAS, APQ, and IEI, while small and inverse associations were seen between TAS and IEI.

CONCLUSIONS

The association with SSAS and APQ suggests that perceptual personality characteristics are important in understanding this disorder.

Mechanisms of increased airway sensitivity to occupational chemicals and odors

PURPOSE OF REVIEW

Airway symptoms induced by chemicals and odors are common problems that are also reported after contact with substances normally regarded as nontoxic. This article reviews current findings and opinions regarding mechanisms of increased airway sensitivity to occupational chemicals and odors.

RECENT FINDINGS

Individuals exposed to organic solvents during work had more nasal irritation and lower threshold to pyridine odor compared with a nonexposed control group. Six percentage of a general population in Sweden had pronounced airway chemical sensitivity and augmented capsaicin cough sensitivity, known to reflect the sensory nerve reactivity of the airways. The cough sensitivity was associated with changed levels of nerve growth factor in nasal lavage and such patients had longstanding symptoms influencing their working capacity. Positron emission tomography activation studies with several different odorants showed in patients with odor-associated symptoms an odorant-related increase in activation of the anterior cingulate cortex and cuneus-precuneus in comparison with a control group.

SUMMARY

In subgroups of individuals with airway symptoms induced by chemicals and odors, there seems to be a sustainable physiological mechanism behind the reactions. An increased vulnerability to stress cannot be neglected as a confounding factor in some sensitive individuals.

General practitioners' experiences with provision of healthcare to patients with self-reported multiple chemical sensitivity

OBJECTIVE

To describe general practitioners' (GPs') evaluation of and management strategies in relation to patients who seek medical advice because of multiple chemical sensitivity (MCS).

DESIGN

A nationwide cross-sectional postal questionnaire survey. The survey included a sample of 1000 Danish GPs randomly drawn from the membership list of GPs in the Danish Medical Association.

SETTING

Denmark.

RESULTS

Completed questionnaires were obtained from 691 GPs (69%). Within the last 12 months 62.4% (n = 431) of the GPs had been consulted by at least one patient with MCS. Of these, 55.2% of the GPs evaluated the patients' complaints as chronic and 46.2% stated that they were rarely able to meet the patients' expectations for healthcare. The majority, 73.5%, had referred patients to other medical specialties. The cause of MCS was perceived as multi-factorial by 64.3% of the GPs, as somatic/biologic by 27.6%, and as psychological by 7.2%. Partial or complete avoidance of chemical exposures was recommended by 86.3%. Clinical guidelines, diagnostic tools, or more insight in the pathophysiology were requested by 84.5% of the GPs.

CONCLUSION

Despite the lack of formal diagnostic labelling the patient with MCS is well known by GPs. The majority of the GPs believed that MCS primarily has a multi-factorial explanation. However, perceptions of the course of the condition and management strategies differed, and many GPs found it difficult to meet the patients' expectations for healthcare. The majority of the GPs requested more knowledge and clinical guidelines for the management of this group of patients.

A two-week monitoring of self-reported arousal, worry and attribution among persons with annoyance attributed to electrical equipment and smells

Non-patients attributing annoyance to either smells (smell annoyed; SA, n= 29) or electrical equipment (electrically annoyed; EA, n= 17), or both (generally annoyed; GA, n= 38), were monitored for 2 weeks through daily self-ratings of arousal (stress), sleep disturbances, health complaints, worry about hypersensitivity reactions, avoidance behaviors, and attributions of health complaints to electrical equipment and smells. In parallel, a demographically matched reference group was followed (n= 56). GA persons reported higher arousal (stress), more subjective health complaints, and more sleep disturbances than the other groups. About 60% in the GA and EA groups reported intentional avoidance behavior, compared to 31% in the SA group and 2% of the referents. Worry and attribution to environmental factors was also more frequent among GA persons than in the other groups. Thus, even at sub-clinical levels, environmental annoyance generalized to several triggers seems to be associated with behaviors commonly observed among patients with idiopathic environmental intolerance.

Multiple chemical sensitivities: review

PURPOSE OF REVIEW

There have been a number of recent studies examining behavioural and social factors in the potential cause of Multiple Chemical Sensitivities, or Idiopathic Environmental Intolerance. The current review will draw together recent research and suggest directions for future investigation.

RECENT FINDINGS

Recent studies have implicated a number of different perspectives which may be helpful in understanding the cause of chemical sensitivities. A multifactorial model incorporating behavioural, physiological and sociological approaches may be useful. Cultural and historical factors, alongside individual expectations and beliefs, as well as maladaptive learning and conditioning processes, may be important in the specific cause of chemical sensitivities. Iatrogenesis, through the promise of unproven 'therapies', may perpetuate reported symptoms further. Although there are many recent experiments implicating potential behavioural or psychological causes for Multiple Chemical Sensitivities, there remains a paucity of treatment trials for this condition.

SUMMARY

Good-quality treatment trials examining psychological/behavioural approaches in the management of Multiple Chemical Sensitivities are urgently needed.

Trait anxiety and modeled exposure as determinants of self-reported annoyance to sound, air pollution and other environmental factors in the home

OBJECTIVES

We examined to what degree annoyance ratings to noise, air pollution and other common environmental factors in the home environment could be considered to mirror personality disposition in terms of habitual anxiety level and, when appropriate, objectively modeled noise and nitrogen emission (NOx).

METHODS

A trait anxiety scale was introduced in a cross-sectional public health survey with 2,856 respondents. Of these, 705 had self-reported asthma and the rest constituted gender-matched referents. Annoyance to ten specific factors in the residential environment, mainly focusing on source-specific noise and air pollution, was assessed on a six-point likert scale. A-weighted energy equivalent continuous sound pressure level during a full day (24 h; L (Aeq,24)) as well as annual average NOx levels (microg/m(3)) at the residential address were modeled with high resolution, using a road data base and a detailed emission data base for NOx.

RESULTS

The two most prevalent complaints were annoyance to traffic noise and sounds from neighbors, which was reported by about 8% of the participants. Unadjusted logistic regression analyses using the continuous trait anxiety score as a predictor showed positive associations with ratings of annoyance from total traffic noise, sounds from neighbors, sound from ventilation, exhaust fumes from traffic, sounds from other installations, and vibrations from traffic (ORs between 1.37 and 2.14). Modeled noise and NOx exposure were positively related with annoyance to traffic noise and exhaust fumes, respectively. Adjustment of the trait anxiety scores for other individual characteristics and potential determinants did not change the overall pattern of results.

CONCLUSION

Trait anxiety scores were often mirrored in ratings of annoyance, which suggests caution when using annoyance reports either as a surrogate measure for environmental exposure on the individual-level in epidemiologic studies or when studying the moderating effects of annoyance on health outcomes.