Odor perception and symptoms during acrolein exposure in individuals with and without building-related symptoms.

Building-related symptoms (BRS) is a significant work-related and public health problem, characterized by non-specific symptoms occurring in a particular building. The cause of BRS is unknown, but certain reactive compounds are suggested risk factors. The aim of this controlled exposure study was to investigate whether BRS cases report more odor annoyance and symptoms and show altered autonomous nervous system (ANS) response during exposure to the reactive aldehyde, acrolein in comparison with referents. Individuals with BRS (n = 18) and referents (n = 14) took part in two exposure sessions (80 min). One session contained heptane alone, and the other heptane and acrolein. Perceived odor annoyance; eye, nose, and throat symptoms; and ANS response were measured continuously. BRS cases did not experience more odor annoyance; eye, nose, and throat symptoms; or altered ANS response in comparison with referents during the exposures. Supplementary analyses revealed that BRS cases that also reported chemical intolerance perceived more symptoms than referents during acrolein exposure. Acrolein exposure at a concentration below previously reported sensory irritation detection thresholds is perceived as more irritating by a subgroup of BRS individuals compared with referents. The results of this study indicate that a subset of individuals with building related symptoms (BRS) has a lowered sensory irritation threshold towards acrolein exposure. Future guidelines on chemical exposures to acrolein should take time and individual sensitivity into account.

A Prospective Study on Risk Factors for Olfactory Dysfunction in Aging.

BACKGROUND: Olfactory dysfunction (OD) refers to a reduced or absent ability to smell. OD negatively impacts health and quality of life and its prevalence increases with advancing age. Since OD may be an early marker of dementia and impending death, more knowledge regarding risk factors of OD in aging is warranted. The objective was therefore to explore longitudinally which demographic, genetic, clinical, lifestyle, and cognitive factors predict the development of OD. METHODS: The study included participants aged 60-90 years from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), who did not have OD at baseline and were reassessed with an odor identification task at a 6-year follow-up (n = 1,004). Risk factors of OD were assessed with multivariable logistic regression analyses. RESULTS: The percentage of incident OD cases was 14.2% over 6 years in the total sample and this number increased monotonically with age. Increasing age, carrying the ε4 allele of the APOE gene, atrial fibrillation, cerebrovascular disease, and current smoking were found to be risk factors for the development of OD, whereas better olfactory identification and verbal episodic memory proficiency at baseline were identified as protective factors. CONCLUSIONS: In addition to nonmodifiable factors (age and genetic risk), several modifiable risk factors of OD were identified. This suggests that it might be possible to reduce OD incidence through the management of vascular risk factors and maintenance of a healthy lifestyle.

Building-Related Environmental Intolerance and Associated Health in the General Population.

People frequently attribute adverse symptoms to particular buildings when exposure to pollutants is low, within nonhazardous levels. Our aim was to characterize building-related intolerance (BRI) in the general population. Data were derived from two population-based questionnaire surveys, the Västerbotten and Österbotten Environmental Health Study. We identified cases of BRI if respondents reported symptoms emerging from residing in certain buildings, when most other people had none. The questionnaires covered lifestyle factors, perceived general health, BRI duration and symptom frequency, the emotional and behavioral impact of BRI, coping strategies, and physician-diagnosed diseases. From the total of 4941 participants, we formed two case groups, 275 (5.6%) fulfilled criteria for self-reported BRI, and 123 (2.5%) for BRI with wide-ranging symptoms. Individuals in both case groups were significantly more often female, single, and perceived their general health as poorer than the referents, i.e., those reporting no BRI symptoms. The mean duration of BRI was 12 years. In both case groups, avoidance behavior was found in over 60%, and nearly half of the sample had sought medical care. BRI with wide-ranging symptoms was associated with elevated odds for all studied comorbidities (somatic and psychiatric diseases and functional somatic syndromes). The perceived health of individuals with BRI is poorer and comorbidities are more frequent than among referents. BRI seems to be similar to other environmental intolerances and shares features with functional somatic syndromes.

Characteristics of perceived electromagnetic hypersensitivity in the general population.

Health problems evoked in the presence of electrical equipment is a concern, calling for better understanding for characteristics of electromagnetic hypersensitivity (EHS) in the general population. The present study investigated demographics, lifestyle factors, frequency and duration, coping strategies, proportion meeting clinical criteria for intolerance attributed to electromagnetic fields (EMF) and comorbidity. Using data from a large-scale population-based questionnaire study, we investigated persons with self-reported (n = 91) EHS in comparison to referents (n = 3,250). Middle age, female sex and poor perceived health was found to be associated with EHS. More than 50% in the EHS group reported having EMF-related symptoms more often than once a week, and the mean number of years experiencing EHS was 10.5. More than half of the EHS group reported that their symptoms started after a high-dose or long-term EMF exposure, that they actively tried to avoid EMF sources and that they mostly could affect the EMF environment. A minority of the EHS group had sought medical attention, been diagnosed by a physician or received treatment. Exhaustion syndrome, anxiety disorder, back/joint/muscle disorder, depression, functional somatic syndrome and migraine were comorbid with EHS. The results provide ground for future study of these characteristic features being risk factors for development of EHS and or consequences of EHS.

Physical and chemical trigger factors in environmental intolerance.

BACKGROUND: Individuals with environmental intolerance (EI) react to exposure from different environmental sources at levels tolerated by most people and that are below established toxicological and hazardous thresholds. The main aim of this study was to determine the prevalence of attributing symptoms to chemical and physical sources in the environment among individuals with different forms of self-reported EI and in referents. METHODS: Cross-sectional data from a population-based study, the Västerbotten Environmental Health Study (n = 3406), were used and individuals with self-reported EI to chemicals, buildings, electromagnetic fields and sounds as well as a group with multiple EIs were identified. The Environmental-Symptom Attribution Scale was used to quantify degree to which health symptoms are attributed to 40 specific environmental exposures and sources, with subscales referring to the four types of EI. RESULTS: All EI groups, except the group with building related intolerance (BRI), reported more symptoms from the expected sources compared to the referents. In addition, individuals with chemical and sound intolerance reported symptoms from building related trigger factors, and individuals with electromagnetic hypersensitivity reported symptoms from chemical trigger factors. CONCLUSIONS: The study suggests that individuals with BRI react to fewer and more specific trigger factors than do individuals with other EIs, and that it is important to ask about different sources since three of the EI groups attribute their symptoms to a wide variety of sources in addition to the sources to which their EI implicates.

Prevalence of various environmental intolerances in a Swedish and Finnish general population.

OBJECTIVE: To determine the prevalence of various environmental intolerances (EIs), using several criteria in a Swedish and a Finnish general population. Ill-health attributed to low-level environmental exposures is a commonly encountered challenge in occupational and environmental medicine. METHODS: In population-based questionnaire surveys, the Västerbotten Environmental Health Study (Sweden) and the Österbotten Environmental Health Study (Finland), EI was inquired by one-item questions on symptom attribution to chemicals, certain buildings, or electromagnetic fields (EMFs), and difficulties tolerating sounds. The respondents were asked whether they react with central nervous system (CNS) symptoms or have a physician-diagnosed EI attributed to the corresponding exposures. Prevalence rates were determined for different age and sex groups and the Swedish and Finnish samples in general. RESULTS: In the Swedish sample (n = 3406), 12.2% had self-reported intolerance to chemicals, 4.8% to certain buildings, 2.7% to EMFs, and 9.2% to sounds. The prevalence rates for the Finnish sample (n = 1535) were 15.2%, 7.2%, 1.6%, and 5.4%, respectively, differing statistically significantly from the Swedish. EI to chemicals and certain buildings was more prevalent in Finland, while EI to EMFs and sounds more prevalent in Sweden. The prevalence rates for EI with CNS-symptoms were lower and physician-diagnosed EIs considerably lower than self-reported EIs. Women reported EI more often than men and the young (18-39 years) to a lesser degree than middle-aged and elderly. CONCLUSIONS: The findings reflect the heterogeneous nature of EI. The differences in EI prevalence between the countries might reflect disparities concerning which exposures people perceive harmful and focus their attention to.

Intolerance to environmental chemicals and sounds in irritable bowel syndrome: Explained by central sensitization?

This study tested the hypotheses of irritable bowel syndrome showing (1) comorbidity with chemical and sound intolerance, other types of functionally somatic syndromes, and psychiatric disorders and (2) stronger than normal affective reactions to and behavioral disruptions from odorous/pungent chemicals and sounds in daily life. These hypotheses were tested by means of data from a large-scale population-based questionnaire study. The results showed comorbidity in irritable bowel syndrome with chemical and sound intolerance, fibromyalgia, migraine, post-traumatic stress disorder, generalized anxiety disorder, panic syndrome, and depression as well as strong reactions/disruptions from odorous/pungent chemicals and sounds in irritable bowel syndrome.

Comorbidity and Multimorbidity of Asthma and Allergy and Intolerance to Chemicals and Certain Buildings.

OBJECTIVES: We tested the hypothesis of high comorbidity between asthma/allergy and chemical intolerance (CI) and between asthma/allergy and building intolerance (BI), and high multimorbidity between asthma/allergy, CI, and BI. METHODS: Population-based questionnaire data were used from 530 participants with asthma/allergy (allergic asthma, nonallergic asthma, allergic rhinitis, and/or atopic dermatitis), 414 with self-reported and 112 with physician-diagnosed CI, and 165 with self-reported and 47 with physician-diagnosed BI. Separate reference groups were formed for each of the five case groups. RESULTS: Adjusted odds ratios varied from 4.6 to 13.1 for comorbidity, and from 6.6 to 46.4 for multimorbidity. CONCLUSION: The large comorbidity and multimorbidity between asthma/allergy, CI, and BI evokes the question as to whether there are similarities in underlying mechanisms between these conditions.

Psychometric Properties and Normative Data for a Swedish Version of the Modern Health Worries Scale.

PURPOSE: The modern health worries (MHW) scale was developed to assess individuals' worries about aspects of modernity and technology affecting personal health. The aim of this study was to psychometrically evaluate a Swedish version of the MHW scale and to provide Swedish normative data. METHOD: Data were collected as part of the Västerbotten Environmental Health Study, which has a random sample of 3406 Swedish adults (18-79 years). RESULTS: The Swedish version of the MHW scale showed excellent internal consistency and satisfactory convergent validity. A four-factor structure consistent with the original version was confirmed. The model showed invariance across age and sex. A slightly positively skewed and platykurtic distribution was found. Normative data for the general population and for combinations of specific age groups (young, middle aged, and elderly) and sex are presented. CONCLUSION: The psychometric properties of the Swedish version of the MHW scale suggest that use of this instrument is appropriate for assessing worries about modernity in Swedish-speaking and similar populations. The scale now has the advantage of good normative data being available. MHW may hold importance for understanding and predicting the development of functional disorders, such as idiopathic environmental intolerance and other medically unexplained conditions.

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.

Symptom-trigger factors other than allergens in asthma and allergy.

Several environmental exposures of particular relevance for indoor air quality, such as exposure to odorants, may be associated with asthma and allergy. The aim of this study was to investigate attribution of symptoms and behavioral disruptions to various chemical and physical environmental sources in persons with self-reported asthma and allergy. Data from a population-based study, the Västerbotten Environmental Health Study, were used to compare persons with asthma, allergic rhinitis, allergic dermatitis, multiple diagnoses of asthma/allergy and no asthma or allergy. Persons with asthma and multiple diagnoses reported odorous/pungent and building-related environmental factors to trigger symptoms to a larger extent than did the reference group, mainly due to perfume and odors from flowers. They also reported behavioral disruptions and affective reactions to odorous/pungent environments. These findings increase the understanding of the role of odorants in symptom development and thereby the prevention of health problems in asthma and allergy in indoor air.

Extent and orientation of coping in chemical intolerance.

Chemical intolerance is a long-standing illness with minimal guidelines regarding treatment. Hence, individual attempts to cope with the illness gain importance in dealing with its consequences. This study used data from 164 persons with self-reported chemical intolerance to understand the nature of coping with the illness. Coping was studied along two dimensions, the extent and predominant orientation of coping. The association of these coping dimensions with mental health variables of stress, depression, anxiety, burnout, and non-restorative sleep was examined as well. Results revealed that the persons with chemical intolerance used a moderate amount of coping strategies which were slightly more emotion-focused than problem-focused in orientation. Users of both problem-focused and emotion-focused orientations report scores in the normal range on all mental health indices. However, significantly higher level of anxiety was found to be associated with predominantly emotion-focused coping, whereas coping orientation did not differ with respect to the four other mental health indices. The above findings are discussed in relation to existing literature on coping with long-term illness.

Coping and social support in asthma and allergy: the Västerbotten Environmental Health Study.

OBJECTIVES: Asthma and allergy are stressful conditions that require coping strategies and social support to reduce stress and enhance health-promoting behavior. However, research is limited regarding coping and social support in asthma and allergy. The aim was to better understand the use of different coping strategies and perceived social support in low and high severity (exacerbation frequency) of asthma and allergy. METHODS: Population-based data were used to provide ratings of coping strategies (Study I) and social support (Study II) from 124 and 94 participants, respectively, with asthma and/or allergy, categorized as low or high in severity. Problem- and emotion-focused coping strategies were assessed as well as emotional, instrumental and informative social support from seven sources. RESULTS: Study I showed that avoiding certain environments (problem-based coping) and trying to accept one's situation (emotion-based) were the most commonly used coping strategies. These behaviors did not differ due to severity. Study II showed that more emotional than instrumental and informative support was perceived. The highest rated support sources were the partner, family members and the healthcare system. More social support was reported in low asthma/allergy severity compared to high asthma/allergy severity. CONCLUSION: The most commonly used coping strategies in the population of persons with these four types of asthma and allergy are avoiding certain environments and trying to accept one's situation. More emotional support than instrumental and informative is perceived to be received, and most of the support is received from one's partner and other family members and least from authorities and patient associations/support groups.

Psychological distress in asthma and allergy: the Västerbotten Environmental Health Study.

With the aim to better understand the association between asthma/allergy and psychological distress, it was hypothesized that levels of stress, exhaustion, anxiety, depression, and health worries for environmental pollution would be higher in allergic asthma, allergic rhinitis, and atopic dermatitis than in non-allergic asthma and in referents without asthma or allergy. Taking part in the population-based Västerbotten Environmental Health Study (aged 18-79 years), 76 respondents reported a physician-based diagnosis of allergic asthma, 86 reported non-allergic asthma, 190 reported allergic rhinitis, and 46 reported atopic dermatitis as the only form of asthma/allergy. A group of 2876 respondents without an asthma/allergy diagnosis constituted as referents. The participants responded to the Perceived Stress Scale, the Shirom-Melamed Burnout Questionnaire, the Hospital Anxiety and Depression Scale, and the Environmental Pollution subscale of the Modern Health Worries Scale. Levels of stress, exhaustion, and anxiety were higher in allergic asthma and atopic dermatitis than in non-allergic asthma, allergic rhinitis, and among referents, and there was a strong tendency of such group differences for depression and health worries. The results imply that stress reduction and treatment of negative affect may in certain cases be fruitful interventions in patients with atopy.

Overlap in prevalence between various types of environmental intolerance.

Environmental intolerance (EI) is characterized by attribution of several, multisystem symptoms to specific environmental exposures, such as exposure to odorous/pungent chemicals, certain buildings, electromagnetic fields (EMFs) and everyday sounds. The symptoms are medically unexplained, non-specific and the symptoms overlap between different types of EI. To approach the issue of underlying mechanisms the matter of overlap in prevalence between intolerances can provide valuable information. The aim of the study was to examine if the overlap between intolerance to odorous/pungent chemicals, certain buildings, EMFs and sounds is larger than the expected overlap if no association would exist between them. The study was using cross-sectional data from the Västerbotten Environmental Health Study in Sweden; a large questionnaire-based survey. 8520 adults (18-79 years) were randomly selected after stratification for age and sex, of whom 3406 (40%) participated. Individuals with the four types of intolerance were identified either through self-report, or by having been physician-diagnosed with a specific EI. The overlaps between the four EIs were greater than predictions based on coincidence for both self-reported and diagnosed cases (except for the overlap between diagnosed intolerance to sounds and EMFs). The results raise the question whether different types of EI share similar underlying mechanisms, or at least that the sufferers of EI share some predisposition to acquire the conditions.

The environmental hypersensitivity symptom inventory: metric properties and normative data from a population-based study.

BACKGROUND: High concomitant intolerance attributed to odorous/pungent chemicals, certain buildings, electromagnetic fields (EMF), and everyday sounds calls for a questionnaire instrument that can assess symptom prevalence in various environmental intolerances. The Environmental Hypersensitivity Symptom Inventory (EHSI) was therefore developed and metrically evaluated, and normative data were established. The EHSI consists of 34 symptom items, requires limited time to respond to, and provides a detailed and broad description of the individual's symptomology. METHODS: Data from 3406 individuals who took part in the Västerbotten Environmental Health Study were used. The participants constitute a random sample of inhabitants in the county of Västerbotten in Sweden, aged 18 to 79 years, stratified for age and gender. RESULTS: EXPLORATORY FACTOR ANALYSIS IDENTIFIED FIVE SIGNIFICANT FACTORS: airway symptoms (9 items; Kuder-Richardson Formula 20 coefficient, KR-20, of internal consistency = 0.74), skin and eye symptoms (6 items; KR-20 = 0.60), cardiac, dizziness and nausea symptoms (4 items; KR-20 = 0.55), head-related and gastrointestinal symptoms (5 items; KR-20 = 0.55), and cognitive and affective symptoms (10 items; KR-20 = 0.80). The KR-20 was 0.85 for the entire 34-item EHSI. Symptom prevalence rates in percentage for having the specific symptoms every week over the preceding three months constitute normative data. CONCLUSIONS: The EHSI can be recommended for assessment of symptom prevalence in various types of environmental hypersensitivity, and with the advantage of comparing prevalence rates with normality.

Metric properties and normative data for brief noise and electromagnetic field sensitivity scales.

AIMS: Lack of brief questionnaire instruments for quantifying affective reactions to and behavioral disruptions attributed to sounds and electromagnetic fields (EMFs) motivated the present development and metric evaluation of such instruments, called the 11-item Noise Sensitivity Scale (NSS-11) and the 11-item Electromagnetic Field Sensitivity Scale (EMFSS-11). Another objective was to establish normative data for these instruments. METHOD: Data from 3406 individuals who took part in the Västerbotten Environmental Health Study was used. The participants constitute a random sample of inhabitants in the county of Västerbotten in Sweden, aged 18 to 79 years, stratified for age and gender. The participants responded to the NSS-11 and EMFSS-11 and to additional questions for evaluation of concurrent validity. RESULTS: The results show satisfying reliability (Cronbach α = 0.71-0.85, varying with age group and gender), concurrent validity, and unidimensionality of the NSS-11 and EMFSS-11, and that the scales generate scores with approximately normal distributions, irrespective of age group and gender. Mean scores, standard deviations, and confidence intervals constitute normative data. CONCLUSIONS: The favorable metric properties of the NSS-11 and EMFSS-11 in combination with their fast usage suggest that they are particularly useful for assessment in epidemiological studies, and have the advantage of available normative data.

Psychometric evaluation and normative data for a Swedish version of the Patient Health Questionnaire 15-Item Somatic Symptom Severity Scale.

The lack of an available Swedish version of the Patient Health Questionnaire 15-Item Somatic Symptom Severity Scale (PHQ-15) motivated the present psychometric evaluation of such a version as well as providing normative data for the PHQ-15. Data from 3,406 individuals who took part in the Västerbotten Environmental Health Study in Sweden were used. The respondents constitute a random sample, aged 18 to 79 years, stratified for age and sex. They responded to a Swedish translation of the PHQ-15 as well as the Hospital Anxiety and Depression Scale, the Perceived Stress Scale, and the Shirom Melamed Burnout Questionnaire for assessment of convergent validity. The distribution of PHQ-15 scores was positively skewed and mesokurtic in shape, and the internal consistency of the PHQ-15 was satisfactory. Correlation coefficients between PHQ-15 score and the measures of anxiety, depression, stress and mental/physical exhaustion indicate satisfactory validity. Normative data for PHQ-15 scores as well as for categories of somatic symptom severity are provided. The favorable psychometric properties of the Swedish version of the PHQ-15 suggest use of this instrument for quantification of somatization in Swedish and similar populations, and has the advantage of available normative data.

Normative data for the chemical sensitivity scale for sensory hyperreactivity: the Västerbotten environmental health study.

OBJECTIVES: The chemical sensitivity scale for sensory hyperreactivity (CSS-SHR) is used to quantify affective reactions to and behavioral disruptions by odorous/pungent substances in the environment and has documented good metric properties. However, normative data have not been available. The main objective of the present study was therefore to establish normative data for reference by means of a large-scale population-based study. MATERIALS AND METHODS: From a random sample of 8,520 reachable inhabitants in the county of Västerbotten in Sweden, aged 18-79 years, stratified for age and gender, 3,406 individuals agreed to participate. RESULTS: The results show fairly high internal consistency (Cronbach's α = 0.78-0.83) of the CSS-SHR and that it generates scores with approximately normal distributions (skewness: 0.045-0.454; kurtosis: -0.314 to 0.230), irrespective of age group and gender. Mean scores, standard deviations, confidence intervals, and proportions of individuals who met the diagnostic cutoff score for the CSS-SHR were obtained for reference of normality. CONCLUSIONS: CSS-SHR can be recommended for quantification of affective reactions to and behavioral disruptions by odorous/pungent environmental substances, and with the advantage of comparing scores with normality.