Validity and recall of information from questionnaires concerning respiratory infections among schoolchildren.

The aim of the study was to assess the reliability of questionnaire information on visits to a physician and the use of antibiotics taken for respiratory infections among schoolchildren attending a water-damaged school and a reference group of schoolchildren attending an undamaged school. Two similar questionnaires on respiratory morbidity in two consecutive years were sent to the parents. The information given on the questionnaires was compared with the patient's records of the local health centre. Although the overall total numbers of ambulatory visits in the patients' records and questionnaires seemed to indicate good reliability, a more detailed individual investigation showed poor recall validity from the questionnaires, including a high percentage of unreported visits to the local health centre from both schools. Underreporting was commoner in the control school than in index school. Recall was best for the children who had no visits to a doctor. Use of antibiotics had a better recall than ambulatory visits in both schools. The study indicates that information on health services in questionnaires is not reliable, at least when occurrences in a period of one year or more are evaluated. The use of patient records as a reference of accuracy is also unreliable, unless all the health care services available to the people in the community are covered.

The remediation of mold damaged school--a three-year follow-up study on teachers' health.

The health effects in teachers of a mold-damaged school before and during an extensive remediation process were assessed. Health data were collected with self-administered questionnaires from teachers (n=31) working in a moisture and mold damaged school and from the reference group of teachers (n=13) working in a non-damaged school. The questionnaire study was repeated three times. Spirometry was measured in 33 individuals in the spring 1997 and repeated in the spring 1999 and 2000. In the damaged school, a cluster of eight asthma cases was identified, the prevalence of asthma being 26%. Before the remediation, the number of sinusitis episodes was higher (p=0.040) and the mean duration of sick leaves longer (p=0.015) among the study group than in the reference group. A higher prevalence of hoarseness and perceived poor quality of indoor air were reported. During the follow-up, no new asthma cases appeared. After the remediation, bronchitis, conjunctivitis, symptoms of allergic rhinitis and the sum of respiratory infection episodes decreased significantly. Some of the asthmatics had low values in the spirometry but no changes in the lung function were observed at the group level. The remediation of the mold damage had beneficial effects on teachers' health.

Joint symptoms and diseases associated with moisture damage in a health center.

Rheumatic diseases do not usually cluster in time and space. It has been proposed that environmental exposures may initiate autoimmune responses. We describe a cluster of rheumatic diseases among a group of health center employees who began to complain of symptoms typically related to moldy houses, including mucocutaneous symptoms, nausea and fatigue, within a year of moving into a new building. Dampness was found in the insulation space of the concrete floor below ground level. Microbes indicating mold damage and actinobacteria were found in the flooring material and in the outer wall insulation. The case histories of the personnel involved were examined. All 34 subjects working at the health center had at least some rheumatic complaints. Two fell ill with a typical rheumatoid factor (RF)-positive rheumatoid arthritis (RA), and 10 had arthritis that did not conform to any definite arthritic syndrome (three met the classification criteria for RA). Prior to moving into the problem building one subject had suffered reactive arthritis, which had then recurred. Another employee had undiagnosed ankylosing spondylitis and later developed psoriatic arthritis, and another developed undifferentiated vasculitis. A total of 16 subjects developed joint pains, 11 of these after beginning work at the health center. Three subjects developed Raynaud's symptom. Fourteen cases had elevated levels of circulating immune complexes in 1998, 17 in 1999, but there were only three cases in 2001, when the health center had been closed for 18 months. The high incidence of joint problems among these employees suggests a common triggering factor for most of the cases. As some of the symptoms had tended to subside while the health center was closed, the underlying causes are probably related to the building itself and possibly to the abnormal microbial growth in its structures.

Does heredity modify the association between farming and allergy in children?

AIM: It has been suggested that living on a farm decreases the risk of childhood allergy, especially if farming involves livestock. The aim of this study was to examine the association between farming and allergy in children, and the influence of atopic heredity in this association. METHODS: The cross-sectional data of the 7981 children aged 13-14 y who participated in the Finnish ISAAC study between the years 1994 and 1995 were used to evaluate the association between farming and allergy. RESULTS: Living on a farm was associated with a decreased risk of current symptoms of allergic rhinoconjunctivitis among all children (aOR 0.79; 95% CI 0.63, 0.99), and with a decreased risk of hay fever, especially among those children with a parental history of hayfever (aOR 0.60; 95% CI 0.40-0.89, p = 0.072 for interaction). The children of farmers with a history of hay fever also had a decreased risk of current wheeze (aOR 0.38; 95% CI 0.12-1.24, p = 0.040 for interaction). No significant association was found between farming and either asthma or eczema. Children living on a farm with livestock had the lowest risk of allergic rhinoconjunctivitis (aOR 0.69), followed by those living on a farm without livestock (aOR 0.89) compared with the non-farming children (p-value for trend 0.024). CONCLUSION: Our results support the recent findings on a decreased risk of allergy among the children living on farms. A possible differential effect of parental history of hay fever on the relation of farming environment and the risk of allergic symptoms warrant further investigation.

Indoor air microbes and respiratory symptoms of children in moisture damaged and reference schools.

Microbial indoor air quality and respiratory symptoms of children were studied in 24 schools with visible moisture and mold problems, and in eight non-damaged schools. School buildings of concrete/brick and wooden construction were included. The indoor environment investigations included technical building inspections for visible moisture signs and microbial sampling using six-stage impactor for viable airborne microbes. Children's health information was collected by questionnaires. The effect of moisture damage on concentrations of fungi was clearly seen in buildings of concrete/brick construction, but not in wooden school buildings. Occurrence of Cladosporium, Aspergillus versicolor, Stachybotrys, and actinobacteria showed some indicator value for moisture damage. Presence of moisture damage in school buildings was a significant risk factor for respiratory symptoms in schoolchildren. Association between moisture damage and respiratory symptoms of children was significant for buildings of concrete/brick construction but not for wooden school buildings. The highest symptom prevalence was found during spring seasons, after a long exposure period in damaged schools. The results emphasize the importance of the building frame as a determinant of exposure and symptoms.

Immunoglobulin G antibodies to moulds in school-children from moisture problem schools.

BACKGROUND: The purpose of the present study was to evaluate mould-specific immunoglobulin G (IgG) antibodies in children exposed to moisture and mould problems in their school, and the association between IgG antibodies and mould allergy, active or passive smoking and respiratory symptoms. METHODS: IgG antibodies were studied to 24 moulds in 93 children from three moisture problem schools and in 33 children from a reference school. The antibodies were measured by enzyme-linked immunosorbent assay and compared to positive adult sera. RESULTS: There were no significant differences in mould-specific IgG concentrations between exposed and non-exposed school-children. Antibodies to moulds common in moisture damaged buildings were associated with allergic diseases, as well as with mould-specific immunoglobulin E (IgE) or skin prick test (SPT) findings. Aspergillus fumigatus and A. versicolor were the moulds with the most consistent findings. Active and passive smoking were associated with low levels of antibodies to many moulds. Though the association between asthma, wheezing or cough symptoms, and IgG to moulds was not significant, 7 (39%) of the 18 children with multiple (> 7) elevated IgG findings suffered from asthma or wheezing. CONCLUSIONS: Allergy was, but asthma was not, associated with IgG antibodies to the moulds that can be found in moisture damaged buildings. However, no association was found between IgG antibodies to moulds and exposure to moisture and moulds in school.

A cluster of inflammatory rheumatic diseases in a moisture-damaged office.

OBJECTIVE: To describe a cluster of inflammatory rheumatic diseases in an office workplace that suggests the presence of an environmental trigger. METHODS: There had been an indoor air problem in the workplace since the early 1990s. Large areas of the outer walls of the building were found to be moisture-damaged and contaminated by microbial growth. Case histories of the personnel were studied, and their working areas were related to the areas with highest microbial contamination. The incidence of inflammatory rheumatic diseases was compared with the statistics of the same geographic area. RESULTS: Ten patients with inflammatory rheumatic diseases (3 rheumatoid arthritis, 4 ankylosing spondylitis, 2 Sjögren's syndrome, and one of psoriatic arthritis) entitled to specially reimbursed medication were diagnosed in 1987-2000 (seven cases in 1995-1998). The incidence density ratio computed for the period 1987-2000 was 6.8 (95% confidence interval 3.6-13.0) for all office personnel and 13.2 (6.0-29.0) for those working close to the wall sustaining the worst damage. CONCLUSION: The accumulation of chronic inflammatory rheumatic diseases in a single workplace suggests that some environmental exposure in this damp office had triggered the diseases.

Comparison of the indoor air quality in mould damaged and reference buildings in a subarctic climate.

The purpose of this study was to search for objective parameters most relevant to indicate microbial problems of buildings in cold climate. Various indoor characteristics were compared in nine buildings with known history of moisture problems and visible mould (index) and in nine matched reference buildings. The concentrations of airborne viable fungal had a clear difference between the two groups of buildings. In this study, airborne concentrations of viable bacteria, formaldehyde, total volatile organic compounds (TVOC) and the occurrence of house dust mites in these index buildings were compared with the levels of the pollutants in matched reference buildings. Fungal growth and flora on moist building materials were also studied. The concentrations of TVOC were slightly higher in the index buildings than in the reference buildings. However, the differences in the concentrations or appearance of any of the studied pollutants were not significant. These parameters do not seem to be relevant indicators of microbial growth or surrogates of microbial exposure. Thus, fungal concentration and composition of fungal genera in the air still seems to be the best indicator for moisture problems among the studied pollutants. In the moist building materials, some fungal genera, such as Ulocladium and Chaetophoma were detected that were not found in indoor air showing that building material samples give additional information on the microflora of the building.

Comparison of two-level and three-level classifications of moisture-damaged dwellings in relation to health effects.

A total of 630 randomly selected dwellings were surveyed for visible signs of moisture damage by civil engineers, and questionnaire responses were collected from the occupants (a total of 1,017 adults) to analyse the association between moisture damage and occupant health. A three-level grading system was developed, which took into account the number of damage sites in buildings and estimated the severity of the damage. In the present study, this grading system was tested as an improved model of moisture damage-related exposure in comparison to a conventional two-category system: based on independent, technical criteria it also allowed dose-response to be estimated. The questionnaire probed 28 individual health symptoms, based on earlier reported associations with building moisture and mould-related exposure. Criteria in evaluating the goodness of the selected exposure model were (1) dose-responsiveness and (2) higher risk compared to a two-level classification. Dose-responsiveness was observed with the three-level classification in 7, higher risk in 10, and both criteria in 5 out of 28 health symptoms. Two-level classification had higher risk in 4 health symptoms. Dose-dependent risk increases for respiratory infections and lower respiratory symptoms, and recurrent irritative and skin symptoms were observed with the three-level classification using symptom score variables. Although the results did not unambiguously support the three-level model, they underline the importance of developing more accurate exposure models in assessing the severity of moisture damage.

Increased prevalence of atopy among children exposed to mold in a school building.

BACKGROUND: The purpose of this study was to assess the occurrence of immunoglobulin E sensitization to common environmental allergens (atopy) and new allergic diseases among schoolchildren after starting school in a water-damaged school building. The staff and pupils of a Finnish elementary school with visible water damage and mold complained of respiratory and skin symptoms. The school building was examined and widespread moisture damage was found. A control school with no visible water damage was also examined. No indication of exceptional microbial growth was found in the samples taken from this school. METHODS: History of allergic diseases and the year of diagnosis were established by a questionnaire. IgE antibodies to the common environmental allergens were determined from randomly selcted groups from both schools. RESULTS: Elevated IgE values were significantly more common among the exposed children, as was the occurrence of new allergic diseases after the children started at the school. CONCLUSIONS: The odds ratios for the IgE values of the study groups indicated a possible relationship between exposure to microorganisms and IgE sensitization. Exposure to spores, toxins, and other metabolites of molds may have complex results with unknown immunogenic effects that may act as a nonspecific trigger for allergic sensitization leading to the development of atopy.

Analysis of moisture findings in the interior spaces of Finnish housing stock.

A grading system was developed to rate the moisture damage profile of dwellings and to study the relationship between moisture-induced indoor air problems and occupant health. A total of 630 randomly selected houses and apartments, built between 1950 and 1989, were visually inspected. Moisture observations were standardized into three damage levels. Thus, a system to classify the homes into three grades was devised. The two grades of homes associated with the highest levels of damage were graded as index homes. Overall, 51% of the sample had some kind of moisture fault in them and one in every three homes (33%) was classified as an index home. The mean number of damage incidents in the index dwellings varied from 1.4 to 2.6. The mean number of damage incidents in the reference homes was 0.28. Prevalence of index dwellings was significantly higher (p < 0.01) in houses (38%) than in apartments (26%). There was no major difference in the prevalence of index buildings in houses built in any particular decade (30-35%). Moisture was observed in 28% of bathrooms, in 10% of kitchens, and in 17% of other spaces. Indoor relative humidity (RH) levels were low in most homes.

Changes in pro-inflammatory cytokines in association with exposure to moisture-damaged building microbes.

Several epidemiological studies have described an association between adverse health effects and exposure to mould and microbes present in the indoor air of moisture-damaged buildings. However, the biochemical linkage between microbial exposure and the large variety of reported respiratory symptoms is poorly understood. In the present study, the authors compared the respiratory symptoms, the production of inflammatory mediators interleukin (IL)-1, IL-4, IL-6, tumour necrosis factor-alpha (TNF-alpha) and cell count in nasal lavage fluid and induced sputum samples of subjects working in moisture-damaged and control school buildings. The sampling was performed and the questionnaires were completed at the end of the spring term, at the end of the summer vacation (2.5 months), during the winter term and after a 1-week winter holiday. The authors found a significant elevation of IL-1, TNF-alpha and IL-6 in nasal lavage fluid and IL-6 in induced sputum during the spring term in the subjects from the moisture-damaged school building compared to the subjects from the control building. The exposed workers reported sore throat, phlegm, eye irritation, rhinitis, nasal obstruction and cough in parallel with these findings. The present data suggests an association between microbial exposure, and symptoms as well as changes in pro-inflammatory mediators detected from both the upper and lower airways.

Respiratory morbidity among children following renovation of a water-damaged school.

The authors sought to determine whether exposure to molds, resulting from moisture damage in a school, was associated with increased respiratory symptoms and morbidity among schoolchildren and whether the renovation of this building resulted in a decrease in prevalence of respiratory symptoms and morbidity. The study was a follow-up (1-y interval) of children between the ages of 7 and 12 y from two elementary schools in a Finnish suburb. In addition to a questionnaire completed by the parents, the authors assessed the respiratory health of children by examining the health records of a local health center. In the cross-sectional study, the prevalence of symptoms and infections were higher in the exposed group, as were visits to a physician and use of antibiotics. The school was renovated, after which all prevalence decreased and no significant differences remained, except for visits to a physician (according to questionnaire responses). Therefore, moisture damage and exposure to molds increased the indoor air problems of schools and affected the respiratory health of children.

Nitric oxide and proinflammatory cytokines in nasal lavage fluid associated with symptoms and exposure to moldy building microbes.

Epidemiological data indicate that living or working in a moldy building is associated with increased risk of respiratory symptoms and disease related to inflammatory reactions, but biochemical evidence linking cause and effect is still scarce. The staff working in a mold-contaminated school, and a reference group without such exposure, were studied. Nasal lavage was performed and health data were collected with a questionnaire at the end of the spring term, after a 2.5-mo summer vacation, and at the end of the fall term. Here we show that concentrations of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and nitric oxide (NO) in nasal lavage fluid were significantly higher in the exposed than in the control subjects at the end of the first exposure period. These inflammatory mediators decreased to reference group concentrations during the period when there was no exposure and the production of NO and IL-6 increased again during the reexposure in the fall term. Reports of cough, phlegm, rhinitis, eye irritation, and fatigue paralleled the changes in the measured inflammatory markers. These results point to an association between inflammatory markers in the nasal lavage fluid, the high prevalence of respiratory symptoms among the occupants, and chronic exposure to molds in the indoor environment.

Infections in early childhood and risk of atopic disease.

Having more siblings has been shown to be associated with lower risk of atopic diseases. This might be due to the higher number of infections in larger families. Because children attending day care centres have more respiratory infections, we analysed the association of number of siblings and day care attendance in children aged 1-3 y with atopic disease in a cross sectional survey of 8387 schoolchildren aged 13-14 y and their parents in four regions of Finland. Having no siblings, compared to three or more siblings, was associated with significantly higher risk of lifetime history of hay fever (odds ratios (OR) 1.53, 95% confidence interval (CI) 1.25-1.86) and atopic eczema (OR 1.28, 95%CI 1.04-1.56), and higher risk (ns) of doctor-diagnosed asthma ever (OR 1.26, 95%CI 0.85-1.88). Less strong associations were observed with the number of older siblings (birth order). No associations were observed with current symptoms of these diseases during the last 12 mo. Attending a day care centre at the age of 1-3 y was not associated with decreased risk of any of the atopic diseases studied, but, in contrast to the hypothesis, was associated with slightly increased risk of current symptoms of hay fever (OR 1.34, 95%CI 1.12-1.60). The present results suggest that other factors than early childhood respiratory infections explain the association between number of siblings and future risk of atopic disease.

An approach to management of critical indoor air problems in school buildings.

This study was conducted in a school center that had been the focus of intense public concern over 2 years because of suspected mold and health problems. Because several attempts to find solutions to the problem within the community were not satisfactory, outside specialists were needed for support in solving the problem. The study group consisted of experts in civil engineering, indoor mycology, and epidemiology. The studies were conducted in close cooperation with the city administration. Structures at risk were opened, moisture and temperature were measured, and the causes of damage were analyzed. Microbial samples were taken from the air, surfaces, and materials. Health questionnaires were sent to the schoolchildren and personnel. Information on the measurements and their results was released regularly to school employees, students and their parents, and to the media. Repairs were designed on the basis of this information. Moisture damage was caused mainly by difficult moisture conditions at the building site, poor ventilation, and water leaks. Fungal genera (concentrations <200 colony-forming units (cfu)/m(3), <3000 cfu/cm(2)) typical to buildings with mold problems (e.g., Aspergillus versicolor, Eurotium) were collected from the indoor air and surfaces of the school buildings. Where moisture-prone structures were identified and visible signs of damage or elevated moisture content were recorded, the numbers of microbes also were high; thus microbial results from material samples supported the conclusions made in the structural studies. Several irritative and recurrent symptoms were common among the upper secondary and high school students. The prevalence of asthma was high (13%) among the upper secondary school students. During the last 4 years, the incidence of asthma was 3-fold that of the previous 4-year period.

Repeated hand urticaria due to contact with fishfood.

BACKGROUND: The etiology of urticaria is often difficult to determine. However, in case of repeated circumstance-connected urticaria, the reason may be easily clarifyable. CASE: A 51-year-old healthy woman repeatedly experienced occupational hand urticaria when handling fish food. An unexpected reason for the urticaria was found in that the fishfood contained histamine as a "contaminant". CONCLUSIONS: In fishfood batches, biological degradation can produce histamine and possibly other toxic substances that can lead to occupational health problems.

The Health Protection Act, national guidelines for indoor air quality and development of the national indoor air programs in Finland.

This article presents the current handling of disease related to moldy buildings in Finland as an example of an integrated health strategy. It describes the role of the Finnish Health Protection Act for indoor environments and how cases of indoor air problems are dealt with by local, regional, and national authorities.

The relationship between moisture or mould observations in houses and the state of health of their occupants.

This work was conducted in order to study how the health of adults is affected by the presence of moisture or mould in the home. A random sample of 310 houses in Finland was studied during the years 1993-1994. The houses were investigated for visual signs of moisture by a surveyor, and observations of mould were reported by the occupants. A moisture problem was observed in 52% and a mould problem in 27% of the houses. Health data was collected by means of a postal questionnaire from 699 adults. Exposure to moisture was significantly associated with sinusitis, acute bronchitis, nocturnal cough, nocturnal dyspnoea and sore throat, and the exposed inhabitants had significantly more episodes of common cold and tonsillitis. Exposure to mould was significantly associated with common cold, cough without phlegm, nocturnal cough, sore throat, rhinitis, fatigue and difficulties in concentration. Building-related moisture or mould increased the risk of upper and lower respiratory infections and symptoms as well as of nonrespiratory symptoms.