Sick building syndrome and associated risk factors among the population of Gondar town, northwest Ethiopia.

BACKGROUND: Sick building syndrome (SBS) consists of a group of mucosal, skin, and general symptoms temporally related to residential and office buildings of unclear causes. These symptoms are common in the general population. However, SBS symptoms and their contributing factors are poorly understood, and the community associates it with bad sprits. This community-based cross-sectional study was, therefore, conducted to assess the prevalence and associated factors of SBS in Gondar town. METHODS: A community-based cross-sectional study was conducted from March to April 2017. A total of 3405 study subjects were included using multistage and systematic random sampling techniques. A structured questionnaire and observational checklists were used to collect data. SBS was assessed by 24 building-related symptoms and confirmed by five SBS confirmation criteria. Multivariable binary logistic regression analysis was used to identify factors associated with SBS on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and p < 0.05. The Hosmer and Lemeshow goodness of fit test was used to check model fitness, and variance inflation factor (VIF) was also used to test interactions between variables. RESULTS: The prevalence of SBS in Gondar town was 21.7% (95% CI = 20.3-23.0%). Of this, the mucosal symptoms account for 64%, the general symptoms account for 54%, and the skin symptoms account for 10%. From study participants who reported SBS symptoms, 44% had more than one symptom. Headache (15.7%), asthma (8.3%), rhinitis (8.0%), and dizziness (7.5%) were the commonest reported symptoms. SBS was significantly associated with fungal growth in the building [AOR = 1.25, 95% CI = (1.05, 1.49)], unclean building [AOR = 1.26, 95% CI = (1.03, 1.55)], houses with no functional windows [AOR = 1.35, 95% CI = (1.12, 1.63)], houses with no fan [AOR = 1.90, 95% CI = (1.22, 2.96)], utilization of charcoal as a cooking energy source [AOR = 1.40, 95% CI = (1.02, 1.91)], cooking inside the living quarters [AOR = 1.31, 95% CI = (1.09, 1.58)], and incensing and joss stick use [AOR = 1.48, 95% CI = (1.23, 1.77)]. CONCLUSION: The prevalence of SBS in Gondar town was high, and significant proportion of the population had more than one SBS symptom. Headache, asthma, rhinitis, and dizziness were the commonest reported SBS symptoms. Fungal growth, cleanliness of the building, availability of functional windows, availability of fan in the living quarters, using charcoal as a cooking energy source, cooking inside the quarters, and incensing habit or joss stick use were identified as factors associated with SBS. Improving the sanitation of the living environment and housekeeping practices of the occupants is useful to minimize the prevalence of SBS.

The Diagnosis of Sick House Syndrome: the Contribution of Diagnostic Criteria and Determination of Chemicals in an Indoor Environment.

OBJECTIVE: The study group for sick house syndrome (SHS) in Japan has proposed the classifications, definition and diagnostic criteria for chemical-associated SHS. We compared the physicians' diagnoses to the diagnoses based on the patients' interview sheets including diagnostic criteria only. METHODS: We examined 287 patients with complaints of SHS-like symptoms. We also checked determinations of chemical substances in the patients' homes. RESULTS: A total of 76.0% of the patients were diagnosed as having SHS. Physicians diagnosed 87.6% of those patients as having chemical-associated SHS based on SHS classifications, definition and diagnostic criteria. Based on the patients' interview sheets, 50.3% of the patients who were diagnosed as chemical-associated SHS corresponded to the diagnostic criteria. The 51 of those chemical-associated SHS patients had answered that the chemical substance levels in their homes had been checked, and 20 of those patients answered that at least one of the chemical substance levels was above that set in the guideline by the Japanese Ministry of Health, Labour and Welfare. CONCLUSIONS: Physicians should use all of the classifications, definition and diagnostic criteria. Even if the chemical levels in the home are under the guideline levels, the diagnosis of chemical-associated SHS should not be excluded.

[Sick building syndrome].

Over the past 50 years, a new man-made ecosystem has developed--the controlled indoor environment within the sealed exterior shells of modern non-industrial buildings. Emitted toxic volatile compounds from building materials, furnishings, and equipment, and inappropriate ventilation (resulting from the need to reduce expenses) contribute to reduce indoor air quality (IAQ), which has considerable potential to affect public health. Consequently, health problems related to this ecosystem have emerged. "Building-related illnesses" (BRI) refers to a group of illnesses with a fairly homogeneous clinical picture, objective abnormalities on clinical or laboratory evaluation, and one or more identifiable sources or agents known to cause infectious, immunologic, or allergic diseases. The term "sick building syndrome" (SBS) is used to refer to a heterogeneous group of work-related symptoms--including irritation of the skin and mucous membranes of the eyes, nose, and throat, headache, fatigue, and difficulty concentrating. These are considered illnesses because of the occurrence of symptoms, even though affected workers do not have objective clinical or laboratory abnormalities and causative agents cannot be found. The clinical symptoms of SBS, although not life-threatening are disruptive: they reduce productivity and increase absenteeism from work. Noteworthy, the association of symptoms with psychosocial factors does not mean that "the problem is all in the workers' heads". The results of psychological testing of symptomatic and asymptomatic office workers are similar. To improve IAQ and reduce symptoms of SBS adequate ventilation and fresh air, which will reduce volatile compounds, maintaining thermal comfort (with humidity not exceeding 60%), and adequate lighting should be ensured.

Classification of patients complaining of sick house syndrome and/or multiple chemical sensitivity.

Sick house syndrome (SHS) is a Japanese concept derived from sick building syndrome (SBS), however SHS includes a broader scope of sickness than does SBS. Symptoms of SHS/SBS disappear after leaving the sick house/building, while symptoms of multiple chemical sensitivity (MCS) are elicited by the chance of chemical exposure after leaving the sick house/building. To establish the concept of SHS, we propose to introduce a new classification for SHS. A total of 214 patients complaining of SHS and/or MCS were independently classified using a new classification by clinical ecologists who are experienced physicians with expert knowledge of clinical ecology and general physicians according to disease pathogenesis from clinical records. The classification is as follows: type 1 (symptoms of chemical intoxication), type 2 (symptoms developed possibly due to chemical exposure), type 3 (symptoms developed not because of chemical exposure but rather because of psychological or mental factors), and type 4 (symptoms developed due to allergies or other diseases). The agreements on the classification made by clinical ecologists and general physicians reached 77.1% (Cohen's kappa=0.631), suggesting that this new classification was both apt and accurate. Relations between SHS and allergy/MCS were also studied. The cases classified as SHS type 4 more frequently had allergic past histories than did other types. The proportion of possible MCS cases was higher in the chemical induced SHS group (types 1 and 2) than in other types among male patients. For the universal use in clinical practice, it is necessary to prepare helpful diagnostic criteria of this SHS classification based on pathogenesis and carry our study forward all over the country.

[Trial of isolation of sick house syndrome and unclassified multiple chemical sensitivities--Definition of sick house syndrome, and symptoms].

PURPOSE: This study was designed to clarify the definition of sick house syndrome (SHS). METHODS: SHS was defined based on the disease related to habitation as follows. 1. The cause of the onset of a disease relates to house. 2. Symptoms appear within house. 3. Symptoms will be less serious or disappear if patient away from house. 4. If patient goes into house, symptoms will appear repeatedly. When it corresponded to all above, it was defined to SHS, and it classified as MCS (multiple chemical sensitivities) without above conditions. Even if SHS is isolated from similar disease completely, characteristic symptoms of MCS are hard to be detected because MCS are combination of two or more diseases. Based on this working hypothesis, the logistic regression by setting MCS as reference was performed so that characteristic symptoms of SHS show odds ratios with exceeding one. RESULTS: The odds ratios with more than two of characteristic symptoms in SHS were "nausea or vomiting" "Troublesome in everything" and the causative substances to which symptoms get worse was "The smell of a perfume and cosmetics". Characteristic symptoms of an allergy disease were detected by comparison with the allergic conjunctivitis, allergic rhinitis, and bronchial asthma, respectively. CONCLUSION: These results showed that the classification method was appropriate. This definition is not fundamentally differed from the definition of the sick-building syndrome of WHO.

Prevalence of building-related symptoms as an indicator of health and productivity.

BACKGROUND: The prevalence of building-related symptoms (BRS) is commonly used to characterize the indoor air quality in office buildings. To analyze the costs of building renovation and the improvement of the indoor environment, it is useful to quantitatively relate the prevalence or intensity of BRS to productivity. The intent of this study is to summarize the links between the BRS and productivity, and demonstrate this linkage in two case buildings. MATERIAL AND METHODS: A literature was surveyed for studies that measured simultaneously the prevalence or intensity of BRS and subjectively reported or objectively measured productivity. Case studies in two office environments were performed. An association between the prevalence of BRS and productivity of workers in a call center and in an insurance office were investigated. In the first case study, the productivity was expressed using the direct productivity metrics, namely the number of telephone contacts during active working hours while in the second case, the productivity was assessed by using the data concerning sick leave rates. RESULTS: Employees who report more BRS also have more often absences which relate to indoor environment quality (IEQ). Their productivity is lower than those who have better IEQ in their offices. Despite uncertainties related to the data concerning recorded sick leave and self-reported productivity, the number of studies showing an association between BRS and productivity or sick leave suggests that such a relationship exists. The present case studies also demonstrated an association between the BRS and the direct productivity. Based on the data from the call center, a reduction of 10%-units in the prevalence of general symptoms (such as fatigue, headache, nausea, etc.) corresponded with a gain of 1.5% in performance. Based on the findings in the insurance company, a reduction of 10%-units in the prevalence of irritation symptoms corresponded with a decrease of 0.7% in the short-term absenteeism. CONCLUSIONS: A review of 23 studies suggests that a linkage exists between typical BRS and productivity indicators such as task or work performance or absence from work. Quantitative associations between BRS and productivity were demonstrated in two office environments. Quantitative associations between BRS and economic metrics enable cost-benefits analysis.

Class separation of buildings with high and low prevalence of SBS by principal component analysis.

In this study, we were able to separate buildings with high and low prevalence of sick building syndrome (SBS) using principal component analysis. The prevalence of SBS was defined by the presence of at least one typical skin, mucosal and general (headache and fatigue) symptom. Data from the Swedish Office Illness Study describing the presence and level of chemical compounds in outdoor, supply, and room air, respectively, were evaluated together with information about the buildings in six models. When all data were included the most complex model was able to separate 71% of the high prevalence buildings from the low prevalence buildings. The most important variable that separates the high prevalence buildings from the low prevalence buildings was a more frequent occurrence or a higher concentration of compounds with shorter retention time in the high prevalence buildings. Elevated relative humidity in supply and room air and higher levels of total volatile organic compounds in outdoor and supply air were more common in high prevalence buildings. Ten building variables also contributed to the separation of the two classes of low and high prevalence buildings.

Subjective perceptions, symptom intensity and performance: a comparison of two independent studies, both changing similarly the pollution load in an office.

The present paper shows that introducing or removing the same pollution source in an office in two independent investigations, one in Denmark and one in Sweden, using similar experimental methodology, resulted in similar and repeatable effects on subjective assessments of perceived air quality, intensity of sick building syndrome symptoms and performance of office work. Removing the pollution source improved the perceived air quality, decreased the perceived dryness of air and the severity of headaches, and increased typing performance. These effects were observed separately in each experiment and were all significant (P < or = 0.05) after combining the data from both studies, indicating the advantages of pollution source strength control for health, comfort, and productivity.

Association of ventilation system type with SBS symptoms in office workers.

This paper provides a synthesis of current knowledge about the associations of ventilation system types in office buildings with sick building syndrome (SBS) symptoms and discusses potential explanations for the associations. Most studies completed to date indicate that relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms, by approximately 30 to 200%. In two of three analyses from a single study (assessments), symptom prevalences were also significantly higher in air-conditioned buildings than in buildings with simple mechanical ventilation and no humidification. The available data also suggest, with less consistency, an increase in risk of symptoms with simple mechanical ventilation relative to natural ventilation. Insufficient information was available for conclusions about the potential increased risk of SBS symptoms with humidification or recirculation of return air. The statistically significant associations of mechanical ventilation and air conditioning with SBS symptoms are much more frequent than expected from chance and also not likely to be a consequence of confounding by several potential personal, job, or building-related confounders. Multiple deficiencies in HVAC system design, construction, operation, or maintenance, including some which cause pollutant emissions from HVAC systems, may contribute to the increases in symptom prevalences but other possible reasons remain unclear.

Indoor environmental exposures and symptoms.

The label "sick building syndrome" is often used to imply the absence of a physiologic basis for symptoms in the built environment. Although building-related illness is widely recognized but considered rare, several well-studied mechanisms may be responsible for many symptoms in buildings. These mechanisms do not explain why some individuals perceive disability. Until researchers distinguish physiologic mechanisms from other aspects of disease and study them systematically, poorly defined symptoms will remain poorly understood. The disability associated with such symptoms and syndromes, not the physiology, is the primary interest and generates controversy.

Effects of temperature and humidification in the office environment.

In this investigation, the authors evaluated the relationship between temperature and (a) Sick Building Syndrome symptoms and (b) workers' perceptions of air dryness in environments with and without humidification. The authors studied the average intensity of symptoms and perceptions of dry air relative to room temperature in humidified and nonhumidified conditions. During the 6 wk of the experiment, 2 wings of the building were humidified one-by-one for 1 wk, followed by a week without humidification. A total of 230 daily questionnaires were completed during the nonhumidified period, and 233 were completed during the humidified period. The results were analyzed with linear regression analysis, and the average intensity of dryness symptoms and sensations of dryness increased with each unit increase in temperature above 22 degrees C, both in the humidified and nonhumidified conditions. Sick Building Syndrome symptoms increased relative only to temperature during the period of no humidification. In conclusion, temperatures above 22 degrees C caused increased dryness symptoms and a sensation of dryness, independent of humidification. The overall intensity of Sick Building Syndrome symptoms increased only when indoor air was not humidified.

[Sick building syndrome should be treated more from a reasonable than an evidence-based point of view]. / Sjuka hus-syndromet får behandlas mer utifrån rimlighet än evidens.

During the past decades, several non-specific syndromes have gradually appeared and eventually been given generic denominations such as "diseases of modern life". One of these is the so called Sick Building Syndrome (SBS), which consists of various combinations of common, non-specific symptoms as well as an absence of signs demonstrable by laboratory tests and other medical examinations or means. The lack of demonstrable biological correlates together with vague etiologic attributions make it unusually problematic to study, resulting in the production of a general, non-specific and sometimes contradictory fund of knowledge. This often transforms instances of SBS to theaters of conflict people by parties with divergent interests. Technical/scientific expertise can provide general advice but not unambiguously contribute to the resolution of the conflicts.