Sick Building Syndrome in an Office Building Formerly Used by a Pharmaceutical Company: A Case Study

Abstract In the past two decades, a group of health problems related to the indoor environment – generally termed sick building syndrome (SBS) – has emerged. We present an investigation of SBS in employees of a ministry working in a naturally ventilated office building that formerly had been used by a pharmaceutical company. A preceding environmental monitoring had failed to identify the cause(s) for the complaints. We conducted a questionnaire-based investigation and categorized the building sections and rooms according to their renovation status and their former use, respectively. The highest level of complaints was found among the employees working in rooms that in the past had been used for the production or storage of various pharmaceutical products suggesting that pharmaceutical odors may be a risk factor for SBS. Clinical laboratory tests did not show any unusual results. We conclude that the former use of a building for production and storage of pharmaceutical products should be considered as a possible risk factor for complaints about indoor air quality, e.g., when advising about or planning for renovations of buildings formerly used for production, handling, or storing of chemicals.     

Allergic and Non-allergic Students' Perception of the Same High School Environment

Abstract The aim of the study was to describe how allergies and non-allergies perceive the same environment. All high school students in a town in southern Sweden were invited to answer a questionnaire concerning allergy, subjective symptoms, annoyance reactions and perception of the environment (response rate: 81%). The results show that only 45% of the students were non-allergic (n = 1,715). Since the symptom frequency among non-allergic students was normal, the schools were classified as healthy. However, compared to the non-allergic students, a higher percentage among the allergies suffered from symptoms every week, a lower percentage was satisfied with the air quality and the cleaning, and a higher percentage was bothered every week by temperature, stuffy/stale air, bad odor, passive smoke, bad lighting, noise, dust and dirt (ANOVA, P < 0.05). The findings could indicate that allergies note discomfort earlier than non-allergies by being more critical in general and especially critical to factors that could effect their health. The findings could also indicate that awareness of ones own sensitivity could lead to attention to different risk factors, which in turn could lead to stress/anxiety, which could make symptoms worse. The conclusion is that it is important to take allergy into consideration when the environment is assessed.     

Application of multicriteria analysis in designing HVAC systems

The present paper discusses a study which aims to develop a method for choosing and managing in the best possible way heating, ventilating and air conditioning (HVAC) systems in new and existing buildings. The method utilises a combination of two analysis’ tools, the multicriteria decision-making and the building simulation towards the direction of a holistic assessment of HVAC systems. In order to evaluate the method, a series of HVAC systems are considered for installing in an office building and the multicriteria method Electre III is applied for their selection. The results show that the proposed model allows the classification of alternative technical solutions concerning the HVAC's design, taking into consideration economic, energy and environmental criteria as well as criteria of users’ satisfaction. Finally, the study also indicates that when applying the sustainability concept in the building sector, and especially in the HVAC systems, this should concern the overall socioeconomic costs.     

Association of Personal and Workplace Characteristics with Health,Comfort And Odor: A Survey of 3948 Office Workers in Three Buildings

A questionnaire on health symptoms, workplace conditions, and perceived indoor air quality was administered to 3948 employees of the Environmental Protection Agency in Washington, DC in the winter of 1989. The main goal was to determine the personal or workplace characteristics associated with health symptoms. A principal components analysis of 32 health symptoms identified 12 health factors. Each factor was generally associated with a particular body system (eyes, nose, throat, chest, central nervous system, etc.). The 12 health factors were regressed linearly on the 50-100 personal, workplace, and spatial characteristics identified from the questionnaire and building blueprints. Significant variables (p < 0.01) were included in a second logistic regression to determine a final model. Eleven variables were associated with multiple health factors. The main workplace variables were dust and glare. Personal characteristics of importance were mold allergies and sensitivity to chemicals. Among women, lack of a college degree was an important factor. Air quality factors of importance included hot stuffy air and dry air: The odor of paint and other chemicals, and the odor of cosmetics were also associated with four or more of the health factors. Two measures of stress – heavy workload and conflicting demands – were also associated with several health factors.     

空调系统设计对病态建筑综合症的影响与对策

针对空调建筑中大量出现的病态建筑综合症，从参数设计，新、回、排风设计、空调方式以及气流组织等方面，阐述了改善室内空气品质的空调系统设计方法和设计理念。     

Individual and Occupational Correlates of the Sick Building Syndrome

Results of a questionnaire survey of 939 workers from 5 air-conditioned offices where smoking was prohibited are reported. Levels of carbon monoxide, carbon dioxide, formaldehde, respirable particulates, and temperature, relative humidity, and illuminance were measured in these buildings, but these did not correlate with symptom reports. The number of sick building syndrome symptoms per worker was related linearly to perceived indoor air quality, job stress, job satisfaction, allergies, eyewear, and seasonal affective disorder. Two hundred and fifty five of these workers also completed a battery of psychological measures. Measures of depression, personality variables, situational stress, vulnerability to stress, and individual differences in circadian rhythms did not correlate with the numbers of sick building syndrome symptoms per worker, although depression did correlate with the number of symptoms when these were weighted for their frequency of occurrence in the previous month. Job stress and perceptions of indoor air quality correlated with both the unweighted and weighted indices of sick building syndrome.     

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     

Perceived Air Quality,Sick Building Syndrome (SBS) Symptoms and Productivity in an Office with Two Different Pollution Loads

Abstract Perceived air quality, Sick Building Syndrome (SBS) symptoms and productivity were studied in an existing office in which the air pollution level could be modified by introducing or removing a pollution source. This reversible intervention allowed the space to be classified as either non-low-polluting or low-polluting, as specified in the new European design criteria for the indoor environment CEN CR 1752 (1998). The pollution source was a 20-year-old used carpet which was introduced on a rack behind a screen so that it was invisible to the occupants. Five groups of six female subjects each were exposed to the conditions in the office twice, once with the pollution source present and once with the pollution source absent, each exposure being 265 min in the afternoon, one group at a time. They assessed the perceived air quality and SBS symptoms while performing simulated office work. The subject-rated acceptability of the perceived air quality in the office corresponded to 22% dissatisfied when the pollution source was present, and to 15% dissatisfied when the pollution source was absent. In the former condition there was a significantly increased prevalence of headaches (P= 0.04) and significantly lower levels of reported effort (P=0.02) during the text typing and calculation tasks, both of which required a sustained level of concentration. In the text typing task, subjects worked significantly more slowly when the pollution source was present in the office (P=0.003), typing 6.5% less text than when the pollution source was absent from the office. Reducing the pollution load on indoor air proved to be an effective means of improving the comfort, health and productivity of building occupants.     

Development of a multiple regression model to identify multi-family residential buildings with a high prevalence of sick building syndrome (SBS)

The aim was to develop a multiple logistic regression model to identify multi-family houses with an increase of sick building syndrome (SBS). In Stockholm, 609 multi-family buildings with 14,235 dwellings were selected by stratified random sampling. The response rate was 77%. Multiple logistic regression analysis was applied, adjusting for ownership of the building, building age and size, age, gender, and atopy. Females, subjects with allergy, those above 65 yr, and those in new buildings reported significantly more SBS. Subjects owning their own building reported less SBS, but the relationship between ownership and building age was strong. A regression model, including factors with a high explanatory value was developed. According to the model, 5% of all buildings built before 1961, 13% of those built 1976-1984, and 15% of those built 1985-1990 would have significantly more SBS than expected. In conclusion, SBS is related to personal factors, building age, and ownership of the building. To identify multi-family buildings with more SBS than expected, it is necessary to adjust for ownership and population characteristics.     

The influence of sampling duration on recovery of culturable fungi using the Andersen N6 and RCS bioaerosol samplers

The influence of sampling duration on recovery of culturable fungi was compared using the Andersen N6 and the Reuter Centrifugal Sampler (RCS). Samplers were operated side-by-side, collecting 15 samples each of incrementally increasing duration (1-15 min). From 270 samples collected, 26 fungal genera were recovered. Species of Alternaria, Aspergillus, Cladosporium, Epicoccum, Penicillium and Ulocladium were most frequent. Data adjusted to CFU/m3 were fitted to a Poisson regression model with a logarithmic link function and evaluated for the impact of sampling time on qualitative and quantitative recovery of fungi, both as individual taxa and in aggregate according to xerotolerance. Significant differences between the two samplers were observed for xerotolerant and normotolerant moulds, as well as Aspergillus spp. and Cladosporium spp. With the exception of Cladosporium spp., overall recoveries were higher with the RCS. When the Andersen N6 was used, the recovered levels of Cladosporium spp. and unidentified yeasts were reduced significantly at sampling times over 6 min. Similarly, when the RCS was used, recovery of Aspergillus spp., Penicillium spp., Ulocladium spp., unidentified yeasts, and low water activity fungi declined significantly at sampling times over 6 min. PRACTICAL IMPLICATIONS: Currently, the industry-wide trend for viable air sampling in indoor environmental investigations is to use sampling times between 2 and 4 min in duration. Our results support the routine use of a 6-min sampling time where low spore loads are expected, resulting in improved limits of detection.     

Determination of Exposure-Response Relationships for Emissions from Building Products

Abstract Building products have been shown to affect the perceived indoor air quality in buildings. Consequently, there is a need for characterizing the emissions from building products in sensory terms to evaluate their impact on the perceived air quality. Determining the exposure-response relationship between concentration of the emission from a building product and human response is recommended. A practical method is proposed based on an air-dilution system connected to the exhaust of a ventilated small-scale test chamber. The method was used to determine the exposure-response relationships for eight building products. For each building product, samples were placed in a test chamber. A typical room was used as a reference to calculate a building-realistic area-specific ventilation rate in the test chamber. A sensory panel assessed the immediate acceptability of polluted air at four different concentrations 3, 10 and 29 days after samples of the building products were placed in the test chambers. The exposure-response relationships show that the impact of dilution of polluted air on the perceived air quality varies between building products. For some building products it may only be possible in practice to improve the perceived air quality marginally by increasing dilution. The results of the present study suggest that for such building products, source control is recommended as the remedy for poor indoor air quality, rather than an increase of the ventilation rate.     

Evaluation of Two Different Questionnaires used for Diagnosing Ocular Manifestations in the Sick Building Syndrome on the Basis of an Objective Index

The paper evaluates ocular manifestations as reported in two different questionnaires completed within one to Two weeks by 164 office workers in four town halls in Copenhagen. Among 14 previously investigated, these town halls constitute the two with the highest and the two with the lowest prevalence of the Sick Building Syndrome (defined as mucous membrane complaints such as eye, nose or throat irritation, and general symptoms such as headaches or fatigue several times a week). There was a highly significant rank correlation in each of the four town halls between the frequency of self-reported ocular manifestations in the two questionnaires. Furthermore, the eye complaints reported in both questionnaires were significantly correlated with an objective measure for eye dryness, investigated using a biomicroscope. By combining the two questionnaires it was possible to define subgroups using both frequency of eye complaints and consistency of reporting in the two questionnaires. The subgroup of 107 subjects with consistency in the frequency of their eye complaints in the two questionnaires showed a significantly higher correlation with the objective index than did the subjects with inconsistent reporting. Furthermore, with increased frequency of complaints and consistency of reporting, not only the prevalence of microscopically determined eye dryness, but also the number of up to 7 different eye symptoms per subject increased, and an increased percentage of these symptoms was found to be related to sensory reactions in the common chemical sense, which earlier has been postulated to be involved in the Sick Building Syndrome. In conclusion, the study shows that data from two different questionnaires on self-reported ocular manifestations associated with the Sick Building Syndrome are reproducible and associated with objective dryness in the eyes.     

Building calibration for IAQ management

Demand Control System (DCV) is designed to optimise the energy consumption with respect to the demand of outdoor air quantity based on the number of people indoors. However, if significant indoor pollutant sources exist, which is not a function of the number of people, the DCV may cause the indoor air quality to be unacceptable. This paper discusses a procedure of calibrating the building in respect of managing the indoor air quality. The objective is to set the minimum fresh air quantity which is a function of the indoor pollutant concentrations rather than metabolic carbon dioxide. Radon is used as an example because it is a common pollutant embedded in the building materials of high-rise buildings in Hong Kong. This paper also presents a year-round record of the indoor air quality in a typical high-rise building which is very useful for building indoor air quality (IAQ) design.     

Field Measurements of Ventilation and Ventilation Effectiveness in an Office/Library Building

Mechanical ventalation system performance involves the provision of adequate amuunts of outdoor air, uniform distribution of ventilation air within the occupied space, and the maintenance of thermal comfort. Standard measurement techniques exist to evaluate thermal comfort and air change rates in mechanically ventilated buildings; procedures to evaluate air distribution or ventilation effectiveness in the field are still being developed. This paper presents measuremetlts of air change rates and ventilation effectivenes in an office/library building in Washington, DC. The tracer gas decay technique was used to measure whole building air change rates. The air change rates during the measurement period were essentially constant at about 0.8 air changes per hour, somewhat below the design specification and above the minimum recmmmded in ASHRAE Standard 62-1989. Ventilation effectiveness was investigated at several locations within the building through the measurement of local tracer gas decay rate and mean local age of air. The ventilation effectiveness measurements serve as an investigation of the applicability of the m e a s u r r n procedures employed, providing insight into the measurement issue of establishing initial conditions, the spatial variation in test results within a building, and the repeatabildy between tests. The results of the ventilation effectiveness meusurements are consistent with good distrhtion of the outdoor air by the ventilation system and good mixing within the occupied space.     

Assessment of airborne bacteria and fungi in food courts

A study was undertaken to determine the effect of variations in temperature, relative humidity, occupancy density and location (indoor/outdoor) on the concentrations of viable airborne bacterial and fungal spores at an air-conditioned and a non air-conditioned food stall in Singapore. Typically, bioaerosols consisted of 50.5% bacteria and 49.5% fungi in the indoor environment. In contrast, for the outdoor environment, bacteria on an average only accounted for 20.6% of culturable airborne microorganisms whereas fungal concentrations were 79.4%. Results on bioaerosol size distributions revealed that 67% of indoor bacteria and 68% of outdoor bacteria, 85% of indoor fungi and 68% of outdoor fungi were associated with fine mode particulates (<3.3 μm). Occupant density was the key factor that affected indoor airborne bacteria concentrations while concentrations of outdoor airborne bacteria depended strongly on ambient temperature. Indoor fungal concentration was positively correlated to relative humidity whereas outdoor fungal concentration was positively correlated to relative humidity and negatively correlated to temperature. The study also compared the biological air quality between a non air-conditioned food stall (Stall A) and an air-conditioned food stall (Stall B). The dining area of the former had lower bacterial concentrations as compared to the latter, while fungal spore’s concentrations showed a reverse trend. The dominant airborne bacteria genera were Staphylococcus, Pseudomonas, Alcaligens, and Corynebacterium whereas Penicillium, Aspergillus and Cladosporium were the most common fungal genera and groups in both food stalls.     

Classification of House Characteristics in a Boston Residential Nitrogen Dioxide Characterization Study

Abstract Building characteristics of dwelling units in the metropolitan Boston area were statistically sorted on the basis of observed associations between the variables. First, associations between categories of house characteristics were determined by cross-table analyses with a pair-wise chi-square test. The key characteristics, which have a significant relationship with many other characteristics, were used to classify the dwelling units into several groups. Two key characteristics, i.e. building type and size of building, were determined. Houses were divided into three groups: single-unit building, small multi-unit (2 to 4 units) building, and large multi-unit (5+ units) building. The building type was not associated with indoor source, but was significantly associated with volume of dwelling unit, air exchange rate, and indoor and outdoor NO₂ concentrations. Lower airflow, smaller volume units, and higher outdoor NC₂ concentrations, in combination with other factors, result in higher indoor NO₂ concentrations in multi-dwelling residential units (apartments and condominiums).     

Relating Sick Building Symptoms to Environmental Conditions and Worker Characteristics

Abstract Recent concern has centered on “sick buildings” in which there has been an unusually high percentage of health complaints by the building's occupants. Typically, these symptoms are thought to be tied to indoor air quality characteristics, such as high levels of respirable particles or volatiles, thermal conditions, etc. In addition, recent studies have drawn connections between “sick building syndrome” (SBS) symptoms and non-environmental variables, i.e., personal and occupational factors. This paper presents a brief review of a study by Hedge et al. (1995) and additional analyses of their data. In a study of 27 air-conditioned office buildings, Hedge et al. measured nine indoor environmental conditions at various locations within each building and concurrently questioned workers on sixteen SBS symptoms and a number of other personal factors. The additional analyses presented in this paper attempt to draw formal statistical connections between SBS symptoms and both personal worker characteristics and indoor air pollutants simultaneously. The analyses were based on symptom severity response variables whic include information not only on the frequency with which an individual experienced a symptom, but also on how much the symptom disrupted the individual's work. Results from sixteen linear mixed effects models indicate that significant predictors are primarily personal and occupational in nature rather than environmental. For a number of the symptoms, additional variability attributable to buildings exists. However, any physical explanation of this variability remains unclear.     

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.     

Case Study of Radon Diagnostics and Mitigation in a New York State School

This is a case study of the radon diagnostics and mitigation performed by the U.S. Environmental Protection Agency's (EPA's) Office of Research and Development in a New York State school building. Research focused on active subslab depressurization (ASD) in the basement and, to a lesser degree, the potential for radon reduction in the basement and slab-on-grade sections using the heating, ventilating, and air-conditioning (HVAC) system. Based on radon diagnostic measurements in the basement, a five-point ASD system was installed, and recommendations were made to increase the outdoor air supply through the basement unit ventilator. Because of the high radon levels in the basement (1720 bequerels per cubic meter, Bq m^?3) and limited subslab pressure field extension, both mitigation approaches were needed to reduce radon to below the current EPA guideline of 148 Bq m^?3. The effects of excavating a suction pit under each of the five suction points were also investigated. Pit excavation, together with adjustment of the airflows at the suction points, decreased average radon levels in the basement by an additional 40 percent. In the slab-on-grade section, it was recommended that the school hire a HVAC contractor to evaluate the unit ventilators for increased outdoor air supply. This was recommended both to improve indoor air quality and because diagnostic measurements indicated that an ASD system would require an excessive number of suction points in the slab-on-grade classroom.