A longitudinal study of sick building syndrome (SBS) among pupils in relation to SO2, NO2, O3 and PM10 in schools in China.

There are fewer longitudinal studies from China on symptoms as described for the sick building syndrome (SBS). Here, we performed a two-year prospective study and investigated associations between environmental parameters such as room temperature, relative air humidity (RH), carbon dioxide (CO2), nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), particulate matter (PM10), and health outcomes including prevalence, incidence and remission of SBS symptoms in junior high schools in Taiyuan, China. Totally 2134 pupils participated at baseline, and 1325 stayed in the same classrooms during the study period (2010-2012). The prevalence of mucosal symptoms, general symptoms and symptoms improved when away from school (school-related symptoms) was 22.7%, 20.4% and 39.2%, respectively, at baseline, and the prevalence increased during follow-up (P<0.001). At baseline, both indoor and outdoor SO2 were found positively associated with prevalence of school-related symptoms. Indoor O3 was shown to be positively associated with prevalence of skin symptoms. At follow-up, indoor PM10 was found to be positively associated with new onset of skin, mucosal and general symptoms. CO2 and RH were positively associated with new onset of mucosal, general and school-related symptoms. Outdoor SO2 was positively associated with new onset of skin symptoms, while outdoor NO2 was positively associated with new onset of skin, general and mucosal symptoms. Outdoor PM10 was found to be positively associated with new onset of skin, general and mucosal symptoms as well as school-related symptoms. In conclusion, symptoms as described for SBS were commonly found in school children in Taiyuan City, China, and increased during the two-year follow-up period. Environmental pollution, including PM10, SO2 and NO2, could increase the prevalence and incidence of SBS and decrease the remission rate. Moreover, parental asthma and allergy (heredity) and pollen or pet allergy (atopy) can be risk factors for SBS.

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.

Enfermedades relacionadas con los edificios / Building related ilness

Tras los cambios realizados en los últimos años enlos edificios modernos como sistemas de ventilaciónforzada, ordenadores, etc., se han descrito una serie deenfermedades relacionadas con ello. El presente trabajose centra en el síndrome del edificio enfermo, queconstituye un grupo de síntomas que lo padecen habitualmentetrabajadores de un mismo edificio “enfermo”y relacionado con su ambiente interior, ya quecomienza la clínica a las horas de entrar en el edificio ymejora a los minutos de alejarse de dicho ambiente. Elorigen probablemente sea multifactorial causado porcontaminantes volátiles del aire interior del edificio,sistema de ventilación, factores relacionados con laorganización del trabajo e incluso dependientes delhuésped. Dado que no existe una única causa se enumeranlos factores de riesgo para desarrollar dicho síndromeasí como los pasos para llegar a su diagnósticoy medidas útiles para evitarlo

Following the changes carried out in recent yearsin buildings, such as ventilation systems, computers,etc., a series of diseases, that are related to this, havebeen described. This paper concentrates on thesyndrome of the sick building, which is formed by agroup of symptoms normally suffered by workers inthe same “sick” building. This syndrome is related toits interior ambience, since the clinical manifestationsappear some hours after entering the building andimproves a few minutes after leaving this ambience.The origin is probably multifactorial: volatile airbornepollutants, the ventilation system, factors related towork organisation, or even dependent on the host.Since there is no single cause, we enumerate the riskfactors in developing this syndrome as well as thesteps for reaching a diagnosis and useful measures forpreventing the sick building

Were volatile organic compounds the inducing factors for subjective symptoms of employees working in newly constructed hospitals?

This study demonstrated possible relationships between environmental, personal, and occupational factors and changes in the subjective health symptoms of 214 employees after the relocation of a hospital in a region of Japan. Eight indoor volatile organic compounds (VOCs) were detected in at least one of the 19 rooms investigated, and total VOC (TVOC) concentrations in 8 rooms exceeded the advisable value (400 microg/m(3)) established by the Ministry of Health, Labour and Welfare of Japan. Formaldehyde was detected in all the investigated rooms, but none of the results exceeded the guideline value (100 microg/m(3)). Multiple logistic regression analysis was applied to select variables significantly associated with the subjective symptoms that can be induced by sick building syndrome. The results showed that subjective symptoms of deterioration in the skin, eye, ear, throat, chest, central nervous system, autonomic system, musculoskeletal system, and digestive system among employees were associated mainly with gender difference and high TVOC concentrations (>1200 microg/m(3)). Long work hours (>50 h per week) in females and smoking in males were to be blamed for the deterioration of their symptoms. The present findings suggest that to protect employees from indoor environment-related adverse health effects, it is necessary to reduce the concentration of indoor chemicals in new buildings, to decrease work hours, and to forbid smoking.

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.

Molds in floor dust and building-related symptoms in adolescent school children.

This stratified cross-sectional epidemiological study included 1053 school children aged 13-17 years. All pupils filled in a questionnaire on building-related symptoms and other relevant health aspects. The following exposure measurements were carried out: room temperature, CO2 level, and relative humidity; building characteristics including mold infestation were assessed, and dust was collected from floors, air, and ventilation ducts during a working day. Dust was examined for endotoxin level, and cultivated for viable molds. We did not find a positive association between building-related symptoms and extent of moisture and mold growth in the school buildings. Five of eight building-related symptoms were significantly and positively associated with the concentration of colony forming units of molds in floor dust: eye irritation, throat irritation, headache, concentration problems, and dizziness. After adjusting for different potentially confounding factors in separate analyses of each symptom, the above-mentioned associations between molds in dust and symptoms were still present, except for concentration problems. However, in none of the analyses was mold exposure the strongest covariate, being secondary to either asthma, hay fever, recent airway infection, or psychosocial factors.

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.

Inflammatory potential of dust from schools and building related symptoms.

AIMS: To test whether the inflammatory potential of dust samples might be used to differentiate schools with high and low prevalence of building related symptoms (BRS) among the occupants. METHODS: Ten schools with high prevalence of BRS and 10 schools with low prevalence were selected. Dust collected from floors, horizontal surfaces, and exhaust outlets was tested at five concentrations on the lung epithelial cell line A549. The potency of the dust (PF) to stimulate IL-8 secretion was calculated from the initial linear part of the dose-response curves. The organic fraction of the dust samples was determined by incineration. RESULTS: The schools with low prevalence of symptoms had a BRS% of 4.4-11.0 and the schools with high prevalence a BRS% of 19.6-31.9. The PF of floor dust and surface dust correlated, and the PF was associated with the organic content of the dust. The schools with low prevalence of symptoms had a significantly lower PF than the schools with high prevalence. Using the cut point value of 4.5 ng IL-8/mg floor dust, significantly more high prevalence schools were found above the cut point than below. CONCLUSION: The PF of the floor dust samples correlated significantly with the prevalence of symptoms in the schools. The content of endotoxin and microorganisms did not seem to explain the inflammatory potential of the dust or BRS, and the substances in the dust causing the inflammatory potential are presently unknown.

Antibodies against molds and mycotoxins following exposure to toxigenic fungi in a water-damaged building.

Exposure to molds in water-damaged buildings can cause allergy, asthma, hypersensitivity pneumonitis, mucus membrane irritation, and toxicity--alone or in combination. Despite this, significant emphasis has been placed only on Type I allergy and asthma, but not on the other 3 types of allergies. In this study, we sought to evaluate simultaneous measurements of immunoglobulin (Ig) G, IgM, IgA, and IgE antibodies against the most common molds, and their mycotoxins, cultured from water-damaged buildings. Antibodies against 7 different molds and 2 mycotoxins were determined by enzyme-linked immunosorbent assay (ELISA) in the blood of 40 controls and 40 mold-exposed patients. The IgG antibody levels against all 7 of the molds used, as well as the 2 mycotoxins, were significantly greater in patients than in controls. The IgM antibody levels were significantly different in patients for only 6 of 9 determinations. Regarding IgA determinations, antibodies were elevated significantly against all antigens tested, except Epicoccum. However, the differences in IgE levels in controls and mold-exposed patients were significant only for Aspergillus and satratoxin. These differences implied that, overall, the healthy control group was different from the mold-exposed patients for IgG, IgM, and IgA antibodies, but not for the IgE anti-mold antibody. Most patients with high levels of antibodies against various mold antigens also exhibited elevated antibodies against purified mycotoxins, indicating that the patients had been exposed to mold spores and mycotoxins. Detection of high levels (colony-forming units per cubic meter) of molds--which, in this study, strongly suggested that there existed a reservoir of spores in the building at the time of sampling--along with a significant elevation in IgG, IgM, or IgA antibodies against molds and mycotoxins, could be used in future epidemiologic investigations of fungal exposure. In addition to IgE, measurements of IgG, IgM, and IgA antibodies should be considered in mold-exposed individuals.

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.

Possible sources of sick building syndrome in a Tennessee middle school.

Sick Building Syndrome has been reported with increasing frequency during recent years. Buildings that have sustained water damage harbor various molds, some of which may be toxic. Students and staff at Central Middle School in Murfreesboro, Tennessee, reported symptoms similar to those associated with Sick Building Syndrome. Upon investigation, investigators noted that a black fungal growth occurred throughout the building on wet cellulose ceiling tiles. Fungal growth of this type is consistent with the genus Stachybotrys. Stachybotrys spores contain macrocyclic trichothecenes, which may cause harm when inhaled or ingested. Bulk sampling of the black mold was initiated, and the samples were cultured in a moist chamber. Testing of the samples confirmed the presence of Stachybotrys spp., a finding that implies that air sampling procedures should ensue. Professional remediation of this potentially hazardous fungal contaminant is therefore recommended.

Hypothesis for induction and propagation of chemical sensitivity based on biopsy studies.

The reactive airways dysfunction syndrome (RADS), the reactive upper airways dysfunction syndrome (RUDS), the sick building syndrome (SBS), and the multiple chemical sensitivity syndrome (MCS) are overlapping disorders in which there is an intolerance to environmental chemicals. The onset of these illnesses is often associated with an initial acute chemical exposure. To understand the pathophysiology of these conditions, a study of the nasal pathology of individuals experiencing these syndromes was undertaken. Preliminary data indicate that the nasal pathology of these disorders is characterized by defects in tight junctions between cells, desquamation of the respiratory epithelium, glandular hyperplasia, lymphocytic infiltrates, and peripheral nerve fiber proliferation. These findings suggest a model for a relationship between the chronic inflammation seen in these conditions and an individual's sensitivity to chemicals. A positive feedback loop is set up: the inflammatory response to low levels of chemical irritants is enhanced due to the observed changes in the epithelium, and the epithelial changes are propagated by the inflammatory response to the chemicals. This model, combined with the concept of neurogenic switching, has the potential to explain many aspects of RADS, RUDS, SBS, and MCS in a unified way.