Health and Indoor Climate Complaints of 7043 office Workers in 61 Buildings in the Netherlands

During the winter of 1988/1989, the relationships between the prevalence of work-related health and indoor climate complaints and a number of building, management, workplace and personal characteristics have been investigated in a study in more than 60 office buildings located throughout the Netherlands. To collect the information, a questionnaire was prepared on health and indoor climate complaints and personal and workplace characteristics. A checklist was used to obtain information on building characteristics More than 7000 questionnaires were completed by the regular users of the buildings investigated. The results showed that the prevalence of symptoms was higher in air-conditioned buildings than in naturally or mechanically ventilated buildings. some other variables were also related with most work-related complaints after adjustment for selected management, personal, workplace and job characteristics. These included gender, work satisfaction in general, presence of allergies and/or respiratory symptoms, and personal control over temperature at the workplace. No differences were found in symptom prevalences between buildings with spray and steam humidification. The combination of air-conditioning and humidification did not lead to further increases in the prevalence of complaints as compared to buildings with only airconditioning or only humidification.     

Symptoms and Perceived Indoor Air Quality among Occupants of Houses and Apartments with Different Ventilation Systems

The purpose of the study was to evaluate the occurrence of symptoms and the perception of poor indoor air quality among the occupants of houses and apartments with different ventilation systems. The study population consisted of the 473 occupants of 242 dwellings in the Helsinki metropolitan area who responded to a self-administered questionnaire (response rate 93.1%) after a two-week period of indoor air quality measurements. The symptoms of interest were those often related to poor indoor air quality including dryness or itching of the skin; dryness, irritation or itching of the eyes; nasal congestion (“blocked nose”) nasal dry-ness; nasal discharge (“runny nose”); sneezing; cough; breathlessness; headache or migraine; and lethargy, weakness or nausea. Perception of coldness; warm-ness; draught; dryness; stuffiness; and sufficiency of air exchange was also requested. The age-standardized period prevalences of the symptoms and complaints were systematically more common among the occupants of the apartments than those of the houses. The occupants of the houses with natural ventilation seemed to have more symptoms and complaints than those with balanced ventilation. However, in the apartments with balanced ventilation the occupants reported, in general, more symptoms and complaints than those with natural ventilation.     

Phase 1 of the California Healthy Building Study: A Summary

Twelve public office buildings were selected for a study of relationships between worker's health symptoms and a number of building, workspace, job, and personal factors. Three buildings were naturally ventilated, three were mechanically ventilated, and six were air conditioned. Information on the prevalences of work-related symptoms, demographics, and job and personal factors were determined via a questionnaire completed by 880 occupants. Several indoor environmental parameters were measured. Logistic regression models were used to evaluate associations between symptom prevalences and features of the buildings, indoor environments, jobs, and personal factors. A substantial fraction of the occupants in these typical office buildings reported frequent work-related symptoms. The occupants of the mechanically ventilated and air conditioned buildings had sipifcantly more symptoms than occupants of the naturally ventilated buildings after adjustment for confounding factors. Increased prevalences of some symptoms were associated with several job and workspace factors including: presence of carpet, increased use of carbonless copy paper and photocopiers, space sharing, and distance from a window     

Evaluating building-related symptoms using the US EPA BASE study results

In order to develop baseline data about United States office buildings, the United States Environmental Protection Agency conducted the Building Assessment Survey Evaluation (BASE) study, a systematic survey of 100 randomly selected United States office buildings, in the 1990s. This paper analyzes the self-reported work-related symptoms and job and workplace characteristics of 4326 respondents and compares results to the National Institute for Occupational Safety and Health's (NIOSH) study of 80 'complaint' buildings. Four distinct groups of symptoms, representing 'tiredness', 'mucosal irritation', 'neuropsychological', and 'lower respiratory' conditions emerged from factor analysis of work-related symptoms. The symptom grouping is identical for both surveys. Although the prevalence of each symptom is significantly higher in the NIOSH than in the BASE sample, there is overlap of the symptom distributions. In the BASE survey, 45% of the work force reported at least one work-related health symptom; 20% reported at least three symptoms. These findings imply that it is counterproductive to dichotomize buildings into healthy vs. unhealthy; instead the prevalence of health problems related to buildings span a continuum. PRACTICAL IMPLICATIONS: These results indicate that most office buildings have occupants who report building-related symptoms. This paper provides practical guidance for the comparison of building prevalences to the BASE normative data. Work-related symptom distributions and symptom groups can improve investigators' ability to identify IEQ problems.     

Association of air-conditioning with respiratory symptoms in office workers in tropical climate

To evaluate the association of heating, ventilation and air-conditioning systems (HVAC) and respiratory symptoms in a tropical city, self-administered questionnaires were given to 2000 individuals working in air-conditioned office buildings and to 500 control workers in naturally ventilated buildings. Reported symptoms from the two populations were analyzed using chi-square tests, univariate and multiple logistic regressions models. Symptoms were the outcome variable and the odds ratios were adjusted by gender, age, accumulated work time, smoking habits and atopic background. There was a 79.8% response rate and there was a positive association of nasal symptoms (odds ratio, OR = 1.59, 95% confidence interval, CI = 1.11-2.28), naso-ocular symptoms (OR = 1.58, 95% CI = 1.05-2.38), persistent cough (OR = 3.04, 95% CI = 2.00-4.63) sinusitis symptoms (OR = 1.85, 95% CI = 1.27-2.71) and building-related worsening of the symptoms (OR = 4.92, 95% CI = 2.93-8.27) with working in air-conditioned buildings. In conclusion, our study suggests that artificial air-conditioning is a matter of concern for respiratory symptoms in cities with hot and humid climate. PRACTICAL IMPLICATIONS: This study suggests that indoor air-related respiratory symptoms are a matter of concern in places with hot and humid climate. The regression models were adjusted by confounders that could be used in further reanalysis of indoor air quality related symptoms and ventilation systems with expanded variety of climatic conditions.     

Investigation of volatile organic compounds in office buildings in Bangkok,Thailand: Concentrations,sources, and occupant symptoms

To conserve energy, office buildings with air-conditioning systems in Thailand are operated with a tight thermal envelope. This leads to low fresh-air ventilation rates and is thought to be partly responsible for the sick building syndrome symptoms reported by occupants. The objectives of this study are to measure concentrations and to determine sources of 13 volatile organic compounds (VOCs) in office buildings with air-conditioning systems in the business area of Bangkok. Indoor and outdoor air samples from 17 buildings were collected on Tenax-TA^™ sorbent tubes and analyzed for individual VOCs by thermal desorption-gas chromatography/mass spectrometry (TD–GC/MS). Building ventilation was measured with a constant injection technique using hexafluorobenzene as a tracer gas. The results show that the VOC concentrations varied significantly among the studied buildings. The two most dominant VOCs were toluene and limonene with average concentrations of 110 and 60.5 μg m⁻³, respectively. A Wilcoxon sum rank test indicated that the indoor concentrations of aromatic compounds and limonene were statistically higher than outdoor concentrations at the 0.05 level, while the indoor concentrations of chlorinated compounds were not. Indoor emission factors of toluene and limonene were found to be highest with the average values of 80.9 and 18.9 μg m⁻² h⁻¹, respectively. Principal component analysis was applied to the emission factors of 13 VOCs, producing three components based on source similarities. Furthermore, a questionnaire survey investigation and field measurements of building air exchange pointed to indoor air complaints related to inadequate ventilation.     

Particulate Matter Intervention Study: A Causal Factor of Building-Related Symptoms in an Older Building

Abstract Five floors of a 20-year old 6-story office building were investigated using an integrated step-by-step investigation strategy. This involved a walkthrough inspection, an occupant questionnaire, and targeted environmental monitoring of indoor air quality and comfort parameters. The initial questionnaire survey revealed a high occurrence of building-related symptoms. The walkthrough inspection and environmental monitoring identified deposits of surface dust (indoor surface pollution – ISP) on carpets and hard surfaces, and elevated levels of carbon dioxide and respirable suspended particulate matter (RSP) throughout the building. An intervention study (blinded to the occupants) was targeted at reducing ISP levels by replacing normal carpet cleaning practices with higher performance vacuum cleaners and improved cleaning practices. The intervention reduced ISP levels and significantly lowered RSP concentrations by approx. 80% from initial values and against control floors. A follow-up SBS questionnaire revealed significant reductions in all but two of the symptoms. The most significant reductions occurred with symptoms of eye irritation, throat irritation, dry unproductive cough, and nose irritation. The study showed that in older buildings with poor ventilation, a build-up of ISP, and elevated RSP levels, using higher performance carpet cleaning practices can reduce RSP to acceptable levels and can reduce SBS symptoms.     

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.     

Ocular,nasal, dermal and respiratory symptoms in relation to heating,ventilation, energy conservation,and reconstruction of older multi-family houses

The aim was to study relationships between symptoms compatible with the sick building syndrome, type of heating and ventilation system, energy saving, and reconstruction in older dwellings. In Stockholm, 4815 inhabitants in 231 multi-family buildings built before 1961 were randomly selected, of whom 3241 participated (77%). Symptoms and personal factors were assessed by a postal questionnaire. Independent information on building characteristics, and energy saving measures was gathered from the building owners. Multiple logistic regression analysis was applied to calculate odds ratios (OR) adjusting for age, gender, hay fever, current smoking, population density, type of ventilation, type of heating system, and ownership of the building. Subjects in buildings with a mechanical ventilation system had less ocular and nasal symptoms (OR = 0.29-0.85). Heating by electric radiators, and wood heating was associated with an increase of most symptoms (OR = 1.18-1.74). In total, 48% lived in buildings that had gone through at least one type of reconstruction or energy saving remedies during the latest 10 years, including exchange of heating or ventilation system, and sealing measures (exchange of windows, sealing of window frames, roof/attic insulation, and phasade insulation). Energy saving was associated with both a decrease and increase of different symptoms. Major reconstruction of the interior of the building was associated with an increase of most symptoms (OR = 1.09-1.90), and buildings with more than one sealing measure had an increase of ocular, nasal symptoms, headache and tiredness (OR = 1.22-2.49). In conclusion, major reconstruction of the interior, direct heated electric radiators, wood heating, and multiple sealing of buildings were associated with an increase of some symptoms. The study supports the view that mechanical ventilation in dwellings is beneficial from a health point of view.     

Mathematical modeling and experimental study on vertical temperature distribution of hybrid ventilation in an atrium building

An extended Gebhart-Block model for large space buildings is proposed in this paper, which is used to predict the vertical temperature distribution of hybrid ventilation. Natural ventilation coupled with air-conditioning is described with a mathematical model. The indoor thermal environment formed by the air-conditioning and the natural ventilation can also be conducted for the potential analysis and optimal use of the natural ventilation. Experiments were carried out in an atrium building in Shanghai Research Institute of Building Sciences. This paper describes aforementioned model, and it is found that the calculation results implying this model agree well with the measurement data.     

Associations between indoor CO2 concentrations and sick building syndrome symptoms in U.S. office buildings: an analysis of the 1994-1996 BASE study data

Higher indoor concentrations of air pollutants due, in part, to lower ventilation rates are a potential cause of sick building syndrome (SBS) symptoms in office workers. The indoor carbon dioxide (CO2) concentration is an approximate surrogate for indoor concentrations of other occupant-generated pollutants and for ventilation rate per occupant. Using multivariate logistic regression (MLR) analyses, we evaluated the relationship between indoor CO2 concentrations and SBS symptoms in occupants from a probability sample of 41 U.S. office buildings. Two CO2 metrics were constructed: average workday indoor minus average outdoor CO2 (dCO2, range 6-418 ppm), and maximum indoor 1-h moving average CO2 minus outdoor CO2 concentrations (dCO2MAX). MLR analyses quantified dCO2/SBS symptom associations, adjusting for personal and environmental factors. A dose-response relationship (p < 0.05) with odds ratios per 100 ppm dCO2 ranging from 1.2 to 1.5 for sore throat, nose/sinus, tight chest, and wheezing was observed. The dCO2MAX/SBS regression results were similar.     

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.     

A comparison of occupant comfort and satisfaction between a green building and a conventional building

It has been argued that “green” buildings have a better indoor environmental quality (as measured by the comfort perceptions of occupants) than conventional buildings and that this translates into a more satisfying workplace for the building's occupants and, in turn, a more productive workforce. To test this we measured the comfort and satisfaction perceptions of the occupants of a green university building and two conventional university buildings with a questionnaire that asked occupants to rate their workplace environment in terms of aesthetics, serenity, lighting, acoustics, ventilation, temperature, humidity, and overall satisfaction. The university buildings at the centre of the study are located in Albury-Wodonga, in inland southeast Australia. The green building, which is naturally ventilated, is constructed from rammed earth and recycled materials. The conventional buildings have heating, ventilating, and air-conditioning (HVAC) systems and are of brick veneer construction. We found no evidence to believe that green buildings are more comfortable. Indeed, the only difference between the buildings was that occupants of the green building were more likely to perceive their work environment as warm, and occupants who felt warm were more likely to describe their work environment as poor. However, the hydronic cooling system of this building was malfunctioning at the time of the study and hence this result cannot be generalised as a difference between green buildings and conventional HVAC buildings. All other aspects of comfort, including aesthetics, serenity, lighting, ventilation, acoustics, and humidity, were not perceived differently by the occupants of the two types of building.     

The influence of personality, measured by the Karolinska Scales of Personality (KSP), on symptoms among subjects in suspected sick buildings

The aim was to study possible relationships between personality traits as measured by the Karolinska Scales of Personality (KSP), a self-report personality inventory based on psychobiological theory, and medical symptoms, in subjects with previous work history in suspected sick buildings. The study comprised 195 participants from 19 consecutive cases of suspected sick buildings, initially collected in 1988-92. In 1998-89, the KSP inventory and a symptoms questionnaire were administered in a postal follow-up study. There were 16 questions on symptoms, including symptoms from the eyes, nose, throat, skin, and headache, tiredness, and a symptom score (SC), ranging from 0 to 16, was calculated. The questionnaire also requested information on personal factors, including age, gender, smoking habits, allergy and diagnosed asthma. The KSP ratings in the study group did not differ from the mean personality scale norm scores, calculated from an external reference group. Females had higher scores for somatic anxiety (P < 0.01), muscular tension (P < 0.001), psychic anxiety (P < 0.01), psychasthenia (P < 0.05), indirect aggression (P < 0.05), and guilt (P < 0.05), while males scored higher on detachment (P < 0.001). Subjects with higher SC were found to display higher degree of somatic anxiety (P < 0.001), muscular tension (P < 0.001), psychic anxiety (P < 0.001), psychasthenia (P < 0.001), inhibition of aggression (P < 0.05), detachment (P < 0.05), suspicion (P < 0.01), indirect aggression (P < 0.01), and verbal aggression (P < 0.05). In addition, ocular, respiratory, dermal, and systemic symptoms (headache and tiredness) were significantly related to anxiety- and aggressivity-related scales. There were associations between personality scales and change of symptom score (SC) during the 9-year period. The associations between KSP personality traits and symptoms were more pronounced in females. In conclusion, there are gender differences in personality and SBS symptoms. Personality may play a role in the occurrence of symptoms studied in indoor environmental epidemiology. Our results support a view that measurement of personality could be of value in future studies and vulnerability to environmental stress. PRACTICAL IMPLICATIONS: Personality and personal vulnerability should be considered in both indoor environmental epidemiology and practical handling of building with suspected indoor problem, especially when the technical investigations fail to identify any obvious technical malfunction. Moreover, personality aspects should be considered among subjects with possible vulnerable personality exposed to environmental stress, and personality diagnosis can be a complementary tool useful when assessing 'sick building patients' in the medical services. We found no evidence of severe personality pathology in among those working in workplaces with environmental problems so called 'sick buildings'.     

Rhinosinusitis and mold as risk factors for asthma symptoms in occupants of a water-damaged building

Abstract Mold exposure in damp buildings is associated with both nasal symptoms and asthma development, but the progression of building-related (BR) rhinosinusitis symptoms to asthma is unstudied. We examined the risk of developing BR-asthma symptoms in relation to prior BR-rhinosinusitis symptoms and microbial exposure among occupants of a damp building. We conducted four cross-sectional health and environmental surveys among occupants of a 20-story water-damaged office building. We defined BR-rhinosinusitis symptom (N?=?131) and comparison (N?=?361) groups from participants' first questionnaire responses. We compared the odds for the development of BR-asthma symptoms between these two groups over the subsequent surveys, using logistic regression models adjusted for demographics, smoking, building tenure, and first-survey exposures to fungi, endotoxin, and ergosterol. The BR-rhinosinusitis symptom group had higher odds for developing BR-asthma symptoms [odds ratio (OR)?=?2.2; 95% confidence interval (CI)?=?1.3-3.6] in any subsequent survey compared to those without BR-rhinosinusitis symptoms. The BR-rhinosinusitis symptom group with higher fungal exposure within the building had an OR of 7.4 (95% CI?=?2.8-19.9) for developing BR-asthma symptoms, compared to the lower fungal exposure group without BR-rhinosinusitis symptoms. Our findings suggest that rhinosinusitis associated with occupancy of water-damaged buildings may be a sentinel for increased risk for asthma onset in such buildings. PRACTICAL IMPLICATIONS: Exposure to mold is associated with the development of asthma in damp building occupants, and rhinitis is known to be a risk factor for asthma. However, there is little information about the degree of risk for the progression of rhinosinusitis to asthma owing to mold exposures in damp buildings. Our study of damp building occupants demonstrates that building-related (BR) rhinosinusitis symptoms were a risk factor for the development of BR asthma symptoms and that exposure to mold (fungi) or other dampness-related agents augments risk for the development of BR asthma symptoms among those with BR rhinosinusitis symptoms. Our findings suggest that occurrence of BR upper respiratory illness in water-damaged buildings may presage future endemic asthma.     

The home environment in a nationwide sample of multi-family buildings in Sweden: associations with ocular,nasal, throat and dermal symptoms,headache, and fatigue among adults

Risk factors at home for ocular, nasal, throat and dermal symptoms, headache, and fatigue were studied in a nationwide questionnaire survey in Sweden, the BETSI study in 2006. Totally, 5775 adults from a stratified random sample of multi-family buildings participated. Associations between home environment factors and weekly symptoms were analyzed by multi-level logistic regression. In total, 8.3% had ocular symptoms; 11.9% nasal symptoms; 7.1% throat symptoms; 11.9% dermal symptoms; 8.5% headache and 23.1% fatigue. Subjects in colder climate zones had more mucosal and throat symptoms but less fatigue and ocular symptoms. Rented apartments had poorer indoor environment than self-owned apartments. Those living in buildings constructed from 1961 to 1985 had most symptoms. Building dampness, mold and mold odor were risk factors, especially headache and ocular symptoms. Lack of mechanical ventilation system was another risk factor, especially for headache. Environmental tobacco smoke (ETS), electric radiators, and crowdedness were other risk factors. Oiled wooden floors, recent indoor painting, and new floor materials were negatively associated with symptoms. In conclusion, building dampness, mold, poor ventilation conditions, crowdedness, ETS, and emissions from electric radiators in apartments in Sweden can increase the risk of ocular, nasal, throat and dermal symptoms, headache, and fatigue.     

上海世博园部分建筑室内空调环境状况测试分析

为了了解上海世博园建筑室内空调环境状况和行为节能情况,采用实测方法对上海世博园13栋建筑的夏季室内空调环境进行了测试分析。结果表明:一些被测建筑的夏季室内空气温度偏低,最低室温为21.7℃;对于南方湿热地区的剧场建筑,采用开敞式建筑方案不利于室内热舒适环境的营造和节能,且仅利用自然通风和蒸发冷却降温手段难以营造出满足人体基本热舒适性要求的室内环境;展厅观众人数快速增加时室温变化较大,但相对湿度变化较小;一些展馆外门常开,冷风渗漏现象比较严重,加强行为节能是展馆建筑节能设计和运行管理需要考虑的一个重要问题。     

Indoor air quality and energy performance of air-conditioned office buildings in Singapore

An integrated indoor air quality (IAQ)-energy audit methodology has been developed in this study in Singapore, which provides a rigorous and systematic method of obtaining the status-quo assessment of an 'IAQ signature' in a building. The methodology entails a multi-disciplinary model in obtaining measured data pertaining to different dimensions within the built environment such as the physical, chemical, biological, ventilation, and occupant response characteristics. This paper describes the audit methodology and presents the findings from five air-conditioned office buildings in Singapore. The research has also led to the development of an indoor pollutant standard index (IPSI), which is discussed in this paper. Other performance indicators such as, the ventilation index and the energy index as well as the building symptom index (BSI) are also presented and discussed in the context of an integrated approach to IAQ and energy. Several correlation attempts were made on the various symptoms, indoor air acceptability, thermal comfort, BSI and IPSI, and while BSI values are found to correlate among them as well as with IAQ and THERMAL COMFORT acceptability, no such correlation was observed between BSI and IPSI. This would suggest that the occupants' perception of symptoms experienced as well as environmental acceptability is quite distinct from IAQ acceptability determined from empirical measurements of indoor pollutants, which reinforces the complex nature of IAQ issues.     

自然通风建筑能耗全年模拟研究

自然通风是降低建筑能耗的重要手段.现有的软件工具难以准确计算自然通风条件下的全年建筑能耗,限制了自然通风在建筑节能设计中的应用.本文从自然通风计算及耦合计箅两方面进行改进,提出了一套可靠、准确的自然通风与热环境耦合计算的模拟方法和对应的评价指标.而后,以建筑能耗模拟软件DeST为平台,开发出了自然通风风量及建筑能耗的全年逐时模拟软件DeST-Vent+.利用DeST-Vent+软件对北京地区3种自然通风类型下办公建筑的全年空调冷负荷进行了模拟计算,分析了不同通风形式的节能潜力.     

室内空气品质改善措施

主要从民用建筑空调系统——全面通风、新风处理和新风质量、送风方式、空调设备、运行工况等方面探讨了如何防止病态建筑的产生,提高室内空气品质,从而使人们享受舒适的现代生活而不会被"病态建筑综合症"侵扰,并就此提出了改善室内空气品质应采取的措施和方法。