Psychosocial Factors and the “Sick Building-Syndrome”. A case-referent study

Abstract The significance of the psychosocial work environment for the prevalence of symptoms compatible with the “sick building syndrome” (SBS) was studied in a case-referent study including 464 office workers, half of whom had symptoms of SBS. A questionnaire was distributed to all subjects, and representatives of the organisations concerned were interviewed. The aim of the study was to investigate the importance of psychosocial and organisational factors in explaining the prevalence of SBS symptoms among office workers. The results showed that psychosocial work characteristics, such as workload and job satisfaction, as well as worry and reorganisation are factors that have a significant impact on the risk of developing the symptoms of SBS.     

Sick Building Syndrome and Psychosocial Factors - a Literature Review

Abstract Sick building syndrome (SBS) with an unknown etiology has led researchers to focus on the role of psychosocial factors in the work environment as well as on individual characteristics in SBS. Recent research has suggested that psychosocial factors are quite strongly associated with SBS. The associations have been confirmed in buildings that were beforehand considered to be problem cases, and also in buildings whose condition was not known in advance. However, SBS symptoms could not be attributed to psychosocial factors alone. Most of the previous studies have supported the conclusion that SBS most likely is of multifactorial origin related to chemical, physical, biological and psychosocial factors that interact or coincide with one another. Unfortunately, for the time being, it is not possible to characterize adequately the relationship between the various risk factors and the possible mechanisms of SBS. There is an urgent need for more empirical research, especially follow-up studies and interventions, for development of the methodology and for new theory-building in order to better understand the relations between environmental factors, personal factors and the symptoms of SBS. In this literature review, SBS is viewed from an occupational stress perspective.     

Prevalence of sick building syndrome symptoms and its associated factors among bank employees in Pokhara Metropolitan,Nepal

A cross-sectional study was conducted to assess the prevalence of sick building syndrome symptoms and its associated factors among bank employees. Data were collected through a self-administered MM040NA questionnaire among 234 employees of commercial banks in Pokhara Metropolitan, Nepal. The prevalence of general, ocular, respiratory, and dermal sick building syndrome symptoms was 47.6%, 11.9%, 11.9%, and 8.1%, respectively. The perceived indoor physical environment was a significant predictor of sick building syndrome symptoms. Besides this, age, disturbance from temperature and work pressure were significantly associated with general symptoms. Ocular symptoms were significantly associated with disturbance from noise at their workplaces and support from fellow workers. Respiratory symptoms were significantly associated with the time spent working with a photocopy machine. Proper maintenance of room temperature, noise control, good ventilation system, and promotion of supportive psychosocial working environment at banks is important to prevent and control the suffering of employees from SBS symptoms.     

Personal and psychosocial factors and symptoms compatible with sick building syndrome in the Swedish workforce

A random sample of 1000 subjects (20-65 years of age) received a postal questionnaire regarding sick building syndrome (SBS), including the three-dimensional model of demand-control-support (DCS). The response rate was 70% (n = 695), and 532 were occupationally active. Female gender and atopy were the main predictors of symptoms. Eye symptoms were more common at low social support combined with strained work situation [odds ratio (OR) 2.37], and at high social support combined with active work situation (OR 3.00). Throat symptoms were more common at low social support combined with either passive (OR 1.86) or strained situation (OR 2.42). Tiredness was more common at low social support combined with either passive (OR 2.41), strained (OR 2.25), or active situation (OR 1.87), and at high social support combined with active work situation (OR 1.83). Low social support combined with either passive (P = 0.01) or strained job situation (P = 0.01) was associated with a higher symptom score (SC). The lowest SC was found at a relaxed work situation, irrespective of social support. In conclusion, female gender, low age, asthma, atopy and psychosocial work environment are associated with symptoms. The three-dimensional model can predict symptoms compatible with SBS, but in a more complex way than earlier research indicated. Practical Implications A multi-disciplinary approach, including psychosocial stress factors as well as personal factors such as gender, age, atopy and asthma, and indoor exposures, should be applied in studies on symptoms compatible with sick building syndrome (SBS). Males and females perceive psychosocial work conditions differently, and may react differently to job stressors. The psychosocial work environment can be as important as gender and atopy as a predictor of SBS symptoms.     

Indoor Air Humidity And Sensation Of Dryness As Risk Indicators Of Sbs

Questionnaire reports on symptoms and sensations from 4943 office workers, measurements of indoor climate from 540 office rooms in 160 buildings, and measurements of TVOC in 85 rooms were used in an analysas of the role of indoor air humidity and the sensation of dryness as risk indicators of SBS (Sick Building Syndrome) symptoms. The sensation of dryness was strongly associated with the prevalence of SBS symptom reports. There were no associations between measured indoor air humidity and the prevalence of SBS symptoms or the sensation of dryness. A number of significant associations were demonstrated between the sensation of dryness and technical, air quality, psychosocial and personal variables. The frequency of reports of perceived “dry air” is an important indicator of the “sickness” of a building; indoor air humidity is not an indicator.     

Building-related symptoms and stress indicators

This study aims to study physiological stress indicators in relation to prevalence of building-related symptoms (BRS) among teachers employed in three selected schools in Copenhagen. Three hypotheses were studied: (i) Perceived psychosocial work environment was associated with BRS; (ii) Perceived psychosocial work environment (job strain) was associated with physiological strain; (iii) BRS was associated with physiological strain. We found a tendency among women of an association between job strain and being BRS positive. Also an association between job strain and physiological strain was observed among women. Being BRS positive was not associated with single physiological stress indicators with the exception of a higher level free testosterone in serum among BRS-positive women. PRACTICAL IMPLICATIONS: Including physiological stress indicators may be a supplementary measure to questionnaires when studying the association between the psychosocial work environment and building-related symptoms (BRS). In this study, job strain was associated with physiological strain among women. Being BRS positive was not associated with single physiological stress indicators with the exception of a higher level free testosterone in serum among BRS-positive women. This study should be regarded as a preliminary study because of its small number of participants.     

The prevalence and incidence of sick building syndrome in Chinese pupils in relation to the school environment: a two-year follow-up study

There are few incidence studies on sick building syndrome (SBS). We studied two-year change of SBS in Chinese pupils in relation to parental asthma/allergy (heredity), own atopy, classroom temperature, relative humidity (RH), absolute humidity (AH), crowdedness, CO?, NO?, and SO?. A total of 1993 participated at baseline, and 1143 stayed in the same classrooms after two years. The prevalence of mucosal and general symptoms was 33% and 28% at baseline and increased during follow-up (P < 0.001). Twenty-seven percent reported at least one symptom improved when away from school. Heredity and own atopy were predictors of SBS at baseline and incidence of SBS. At baseline, SO? was associated with general symptoms (OR=1.10 per 100 μg/m3), mucosal symptoms (OR=1.12 per 100 μg/m3), and skin symptoms (OR=1.16 per 100 μg/m3). NO? was associated with mucosal symptoms (OR=1.13 per 10 μg/m3), and symptoms improved when away from school (OR=1.13 per 10 μg/m3). Temperature, RH, AH, and CO? were negatively associated with prevalence of SBS. Incidence or remission of SBS was not related to any exposure, except a negative association between SO? and new skin symptoms. In conclusion, heredity and atopy are related to incidence and prevalence of SBS, but the role of the measured exposures for SBS is more unclear. PRACTICAL IMPLICATIONS: We found high levels of CO? indicating inadequate ventilation and high levels of SO? and NO?, both indoors and outdoors. All schools had natural ventilation, only. Relying on window opening as a tool for ventilation in China is difficult because increased ventilation will decrease the level of CO? but increase the level of NO? and SO? indoors. Prevalence studies of sick building syndrome (SBS) might not be conclusive for causal relationships, and more longitudinal studies on SBS are needed both in China and other parts of the world. The concept of mechanical ventilation and air filtration should be introduced in the schools, and when planning new schools, locations close to heavily trafficked roads should be avoided.     

Sick Building Syndrome (SBS) in Office Workers and Facial Skin Symptoms among VDT-Workers in Relation to Building and Room Characteristics: Two Case-Referent Studies

In two case-referent studies the associations between questionnaire symptom reports, expressed as SBS (Sick Building Syndrome) in office workers or facial skin symptoms among VDT-workers, and physical data from offices in 160 buildings were investigated. The results show that low outdoor airflow rate and presence of certain pollution sources, such as copying machines, tended to be associated with an elevated prevalence of SBS. Buildings built or remodeled between 1977 and 1986, low-rise buildings with a horizontal roof and a foundation of the type “concrete slab on the ground”, as well as rooms with flourescent tube lighting with metal shields were also associated with higher SBS risks. A number of factors were associated with an overrepresentation of skin symptoms among VDT-workers such as type of foundation (concrete slab on the ground and crawlspace), the frequency of floor cleaning and type of lighting (fluorescent tubes with glass/plastic shields). It has not been possible to establish conclusive explanations for these associations. The difference in associations between building factors and S B S, and between building factors and skin symptoms among VD Tworkers points to different etiologies.     

External eye symptoms in indoor environments

Eye irritation, for example dry or irritated eyes, is generally among top three reported symptoms in office‐like environments, in particular among workplaces with cognitive demanding visual display unit (VDU) work. The symptoms are especially among middle and advanced ages and particularly among women more than men. The symptoms are also among the most commonly reported complaints in the eye clinic. To be in a position to interpret the high prevalence of eye symptoms, a multidisciplinary and integrated approach is necessary that involves the external eye physiology (separate from internal eye effects), eye diseases (evaporative dry eye (DE), aqueous‐deficient DE, and gland dysfunctions), and risk factors that aggravate the stability of precorneal tear film (PTF) resulting in hyperosmolarity and initiation of inflammatory reactions. Indoor environmental, occupational and personal risk factors may aggravate the PTF stability; factors such as age, contact lenses, cosmetics, diet, draft, gender, low humidity and high temperature, medication, outdoor and combustion pollutants, and VDU work. Psychological stressors may further influence the reporting behavior of eye symptoms. The impact of the risk factors may occur in a combined and exacerbating manner.     

Does office space occupation matter? The role of the number of persons per enclosed office space,psychosocial work characteristics,and environmental satisfaction in the physical and mental health of employees

The study examined the effects of office space occupation, psychosocial work characteristics, and environmental satisfaction on physical and mental health of office workers in small‐sized and open‐plan offices as well as possible underlying mechanisms. Office space occupation was characterized as number of persons per one enclosed office space. A total of 207 office employees with similar jobs in offices with different space occupation were surveyed regarding their work situation (psychosocial work characteristics, satisfaction with privacy, acoustics, and control) and health (psychosomatic complaints, irritation, mental well‐being, and work ability). Binary logistic and linear regression analyses as well as bootstrapped mediation analyses were used to determine associations and underlying mechanisms. Employee health was significantly associated with all work characteristics. Psychosocial work stressors had the strongest relation to physical and mental health (OR range: 1.66–3.72). The effect of office space occupation on employee health was mediated by stressors and environmental satisfaction, but not by psychosocial work resources. As assumed by sociotechnical approaches, a higher number of persons per enclosed office space was associated with adverse health effects. However, the strongest associations were found with psychosocial work stressors. When revising office design, a holistic approach to work (re)design is needed.     

Subjective Indoor Air Quality in Schools – The Influence of High Room Temperature,Carpeting, Fleecy Wall Materials and Volatile Organic Compounds (VOC)

There is a growing concern about indoor air quality (IAQ) in schools. We have studied relations between subjective indoor air quality (SIAQ) and measured IAQ among school personnel (N = 97) in six mid-Swedish primary schools. Information on SIAQ and the psychosocial work environment was measured by a self-administered questionnaire, using analogue rating scales. Indoor exposures were quantified by hygienic measurements. Perception of high room temperature was related to a poor climate of cooperation, fleecy wall materials, and the concentration of volatile organic compounds (VOC), including xylene, limonene, and butanols. Perception of air dry-ness was related to atopy, work stress, poor climate of cooperation, high room temperature, low air humidity, and high VOC concentration, including, limonene, and n-alkanes. Perception of dusty air was related to work stress, the role of schoolteacher, and exposure to 2-ethyl-1-hexanol. No relations were found between SIAQ and CO2, building age, or respirable dust. To achieve a good SIAQ, room temperature should be kept at a maximum of 22°C, and exposure to VOCs and fleecy materials should be minimized. Finally, a sound psychosocial work climate is essential for the perception of a good physical indoor climate.     

Indoor climate, psychosocial work environment and symptoms in open-plan offices

To study the indoor climate, the psychosocial work environment and occupants' symptoms in offices a cross-sectional questionnaire survey was made in 11 naturally and 11 mechanically ventilated office buildings. Nine of the buildings had mainly cellular offices; five of the buildings had mainly open-plan offices, whereas eight buildings had a mixture of cellular, multi-person and open-plan offices. A total of 2301 occupants, corresponding to a response rate of 72%, completed a retrospective questionnaire. The questionnaire comprised questions concerning environmental perceptions, mucous membrane irritation, skin irritation, central nervous system (CNS) symptoms and psychosocial factors. Occupants in open-plan offices are more likely to perceive thermal discomfort, poor air quality and noise and they more frequently complain about CNS and mucous membrane symptoms than occupants in multi-person and cellular offices. The association between psychosocial factors and office size was weak. Open-plan offices may not be suited for all job types. PRACTICAL IMPLICATION: Open-plan offices may be a risk factor for adverse environmental perceptions and symptoms.     

Symptoms prevalence among office employees and associations to building characteristics

A cross-sectional study was performed in eight companies, comprising 32 buildings without previously recognized indoor air problems. Engineers filled in a technical questionnaire on building characteristics, floor surface materials, ventilation, cleaning procedures, heating and cooling. A total of 3562 employees returned questionnaires on individual factors, workload, perceived physical work environment, allergy and symptoms. Frequent symptoms were feeling of fatigue or heavy-headedness, eye irritation, and dry facial skin. Women reported symptoms more frequently than men. Employees with allergy had a 1.8-2.5 times risk of reporting a high score for general, skin, or mucosal symptoms. The risk of a high symptom score increased with daily visual display unit (VDU) work time. Passive smoking and psychosocial load were also relatively strong predictors of symptoms. Weekly cleaning as compared with a frequency of cleaning two to four times a week increased the risk of symptoms. Adjusted odds ratio for a high general symptoms score from infrequent cleaning was 1.5 (95%CI 1.1-2.0). A high ventilation flow or central ventilation unit filter EU7 vs. EU8 seemed to be associated with an increased risk of general symptoms. Absence of local temperature control increased the risk of mucosal symptoms.     

Non-Specific Symptoms In Office Workers: A Review And Summary Of The Epidemiologic Literature

Epidemiologic research into the causes of non-specific symptoms among office workers has produced a variety of conflicting findings which are difficult to synthesize. This paper first discusses methodologic issues important in the interpretation of epidemiologic studies, and then reviews the findings of 32 studies of 37 factors potentially related to office worker symptoms. Among environmental factors assessed, there were generally consistent findings associating increased symptoms with air-conditioning, carpets, more workers in a space, VDT use, and ventilation rates at or below 10 liters/second/person. Studies with particularly strong designs found decreased symptoms associated with low ventilation rate, short-term humidification, negative ionization, and improved office cleaning, although studies reviewed showed little consistency of findings for humidification and ionization. Relatively strong studies associated high temperature and low relative humidity with increased symptoms, whereas less strong studies were not consistent. Among personal factors assessed, there were generally consistent findings associating increased symptoms with female gender, job stress/dissatisfaction, and allergies/asthma. For other environmental or personal factors assessed, findings were too inconsistent or sparse for current interpretation, and there were no findings from strong studies. Overall evidence suggested that work related symptoms among office workers were relatively common, and that some of these symptoms represented preventable physiologic effects of environmental exposures or conditions. Future research on this problem should include blind experimental and case-control studies, using improved measurements of both environmental exposures and health outcomes     

Sick building syndrome—A case study in a multistory centrally air-conditioned building in the Delhi City

Recently, airtight envelope system has become popular in the design of office buildings to reduce heating and cooling loads. Maintaining allowable indoor air quality (IAQ) for such airtight buildings totally depends on mechanical ventilation systems. Subsequently, poor operation of the ventilation system in such office buildings causes ineffective removal of polluted indoor air, and displays a sign of “sick building syndrome” (SBS). User's perception is an important parameter for evaluating IAQ. A questionnaire study was carried out to investigate the prevalence of the SBS at a multistory centrally air-conditioned Airport Authority of India (AAI) building in the New Delhi city. Quantification of the perceptions of the users regarding IAQ was done by converting their responses to a SBS score. The quantified answers were then subjected to statistical analysis. Qualitative analysis of the questionnaire was carried out to evaluate relationships between SBS score and carbon dioxide (CO₂) and other parameters related to building and work environment. Quantitative analysis of IAQ was also conducted by monitoring indoor concentrations of four pollutants, namely, nitrogen dioxide (NO₂), sulphur dioxide (SO₂), suspended particulate matter (SPM) and carbon monoxide (CO). Concentrations of pollutants were complying with IAQ standards as given by ASHRAE and WHO. The SBS was higher on the third floor as compared to other floors and the control tower. The main symptoms prevailing were headache (51%), lethargy (50%), and dryness in body mucous (33%). The third floor and the control tower were affected by infiltration, mainly from entrance doors. A direct relation between the average SBS score and CO₂ concentration was found, i.e., the average SBS score increased with CO₂ concentration and vice versa, clearly signifying the usefulness of SBS score in IAQ.     

Skin Symptoms among VDT Workers and Electromagnetic Fields - a Case Referent Study

This case referent study is a part of the Office Illness Project in Northern Sweden. From a questionnaire study among 5 986 office workers, 75 VDT workers with self-reported facial skin symptoms and the same number of referents were selected for this study. The environmental electric and magnetic fields in the office as well as electromagnetic fields associated with the VDT at the workplace were measured. The aim of this pan of the project was to explore the role of the measured electromagnetic parameters in relation to skin symptoms. For most of the measured parameters there was no difference between cases and referents. However, more cases than referents were found in the highest exposure group for two of the measured parameters. For the background electric field in the room the relative risk in terms of crude odds ratio (OR) was 3.0 (95% CI: 1.2–7.2) for the high exposed group (≥31 V/m) compared with the lowest group (≤10 V/m). The same comparison for the magnetic field in the ELF-range (≥0.30 μT vs ≤0.145 μT) in front of the VDT gave an OR of 2.7 (95% CI: 1.0–6.9).     

Air quality and well-being perception in subjects attending university libraries in Modena (Italy)

We studied four libraries in the University of Modena and Reggio Emilia (Northern Italy) to determine the presence of polluting agents such as total dusts, formaldehyde and other volatile organic compounds (VOCs) including benzene, toluene and xylenes and to assess the sense of well-being perceived by library users. This investigation was suggested by an increase in reported symptoms related to Sick Building Syndrome (SBS) observed in recent decades among people spending most of their time in various indoor environments, including libraries. The microclimatic conditions and the concentrations of pollutants indicated an acceptable situation on the whole, even though a wide range of total dust values (40-350 microg/m3) and total VOCs (203-749 microg/m3) was observed. However, the perception of the different environmental parameters by the 130 library users that were interviewed identified the existence of some discomfort mainly caused by the feeling of poor ventilation. Moreover, 78.5% of the subjects stated they had at least one of the 16 investigated symptoms potentially related to a SBS. The place of occurrence of the self-reported symptoms was also investigated, the symptoms arising during library attendance more frequently than elsewhere were only four, and in particular feeling hot, sore eyes, dry throat and breathing difficulties. Overall, our study has shown the existence of an association between microclimatic perceptions as reported by library users and subjective symptoms related to SBS, considering the four libraries separately, the highest prevalence of self-reported symptoms was found in the library where environmental discomfort as perceived by users was greatest. Nevertheless, an association between subjective self-reported symptoms and both microclimatic conditions as resulted by instrumental measurements and/or pollutants concentrations was not apparent.     

A longitudinal study of sick building syndrome among pupils in relation to microbial components in dust in schools in China

There are few longitudinal studies on sick building syndrome (SBS), which include ocular, nasal, throat, and dermal symptoms, headache, and fatigue. We studied the associations between selected microbial components, fungal DNA, furry pet allergens, and incidence and remission of SBS symptoms in schools in Taiyuan, China. The study was based on a two-year prospective analysis in pupils (N = 1143) in a random sample of schools in China. Settled dust in the classrooms was collected by vacuum cleaning and analyzed for lipopolysaccharide (LPS), muramic acid (MuA), and ergosterol (Erg). Airborne dust was collected in Petri dishes and analyzed for cat and dog allergens and fungal DNA. The relationship between the concentration of allergens and microbial compounds and new onset of SBS was analyzed by multi-level logistic regression. The prevalence of mucosal and general symptoms was 33% and 28%, respectively, at baseline, and increased during follow-up. At baseline, 27% reported at least one symptom that improved when away from school (school-related symptoms). New onset of mucosal symptoms was negatively associated with concentration of MuA, total LPS, and shorter lengths of 3-hydroxy fatty acids from LPS, C14, C16, and C18. Onset of general symptoms was negatively associated with C18 LPS. Onset of school-related symptoms was negatively associated with C16 LPS, but positively associated with total fungal DNA. In general, bacterial compounds (LPS and MuA) seem to protect against the development of mucosal and general symptoms, but fungal exposure measured as fungal DNA could increase the incidence of school-related symptoms.     

Relationships between occupant personality and the sick building syndrome explored

Increasing evidence shows that certain personality traits, such as negative affectivity (trait NA), are strongly associated with the reporting of symptoms. The role of personality in sick building syndrome (SBS) symptom reporting is therefore explored with the aid of a questionnaire completed by occupants living in apartments with indoor climate problems. A good fit to empirical data was obtained for a path model in which somatization intervenes between a general psychological factor (predominated by trait NA) and SBS. Occupants with "normal" and "aberrant" NA profiles were classified by cluster analysis and further divided according to frequency of symptoms. For occupants with 5 or more SBS symptoms, those with "aberrant" NA profiles have very similar SBS symptom profiles to those with "normal" NA profiles. This indicates that an occupant's trait NA score cannot be used for predicting his or her SBS symptom profile or frequency of SBS symptoms. An unexpected finding was that the occupants with "aberrant" NA profiles also perceived factors in the indoor (air) environment as less adverse than the 5 or more symptom reporting occupants with "normal" NA profile. Pennebaker and Brittingham's competition of external and internal cues model may explain the results for the occupants with "aberrant" NA profiles, however, our empirical data indicate that, unexpectedly, these occupants may not over-report SBS symptoms but rather under-report adverse environmental perceptions.     

Mechanical Ventilation in Office Buildings and the Sick Building Syndrome. An Experimental and Epidemiological Study

The effects of mechanical ventilation on the sick building syndrome (SBS) were studied in an office building with 2150 employees, where the mechanical ventilation and indoor air quality were commonly blamed for causing symptoms typical of the SBS (nasal, eye, and mucous membrane symptoms, lethargy, skin symptoms and headache). The mechanical ventilation rates in the building were high (mean 26 l/s/person). To test the hypothesis that mechanical ventilation causes the SBS, a controlled experimental study was carried out by shutting off the ventilation in one part of the building and reducing the ventilation rate by 75% and 60% in two areas while leaving one part unaltered as a control. The experimental reduction of the ventilation rate did not alleviate the symptoms. On the contrary, the reduction of the ventilation rate caused a slight but statistically significant relative increase in symptoms (p < 0.05). In the cross-sectional analysis of the baseline data the SBS symptoms did not associate significantly with the ventilation rate (range 7–70 l/s/person). In the linear regression model, a positive correlation was found between temperatures above 22°C and the occurrence of symptoms (p < 0.05). Subjects exposed to environmental tobacco smoke had more symptoms than those not exposed (p < 0.01). Women reported more symptoms than men (p < 0.001). In addition, any prior history of allergic diseases (p < 0.001) and a negative attitude towards the social atmosphere at work (p < 0.001) were significant determinants of the SBS.