Meta-analyses of the associations of respiratory health effects with dampness and mold in homes

Confirmed moisture damage at home, respiratory symptoms and atopy in early life: a birth-cohort study

OBJECTIVES

Most previous studies on the association between moisture or mold problems in the home and respiratory symptoms in children were cross-sectional and based on self-reported exposure. The aim of this study was to evaluate the impact of objectively observed moisture damage and visible mold in the homes on early-life respiratory morbidity and atopic sensitization in a birth cohort.

METHODS

Building inspection was performed by building engineers in the homes of 396 children, and the children were followed up with questionnaires from birth to the age of 18 months. Specific immunoglobulin E levels were measured at the age of 1 year.

RESULTS

Doctor-diagnosed wheezing was associated with the severity of moisture damage in the kitchen and with visible mold in the main living area and especially in the bedroom of the child. The risk for parent-reported wheezing apart from cold increased with the severity of moisture damage in the kitchen. Moisture damage in the bathrooms or other interior spaces had no significant association with wheezing. No significant associations were observed for other end points, such as cough, or respiratory infections. There was a suggestion for an increased risk for sensitization to cat dander linked with moisture and mold exposure.

CONCLUSIONS

This birth-cohort study supports previous observations that moisture mold problems in the kitchen and in the main living area increase the risk for wheezing in early childhood. The results underline the importance of assessing separately the health effects of moisture and mold problems in different areas of the home.

A new multiple regression model to identify multi-family houses with a high prevalence of sick building symptoms "SBS", within the healthy sustainable house study in Stockholm (3H)

PURPOSES

The aim was to develop a new model to identify residential buildings with higher frequencies of "SBS" than expected, "risk buildings".

METHODS

In 2005, 481 multi-family buildings with 10,506 dwellings in Stockholm were studied by a new stratified random sampling. A standardised self-administered questionnaire was used to assess "SBS", atopy and personal factors. The response rate was 73%. Statistical analysis was performed by multiple logistic regressions.

RESULTS

Dwellers owning their building reported less "SBS" than those renting. There was a strong relationship between socio-economic factors and ownership. The regression model, ended up with high explanatory values for age, gender, atopy and ownership. Applying our model, 9% of all residential buildings in Stockholm were classified as "risk buildings" with the highest proportion in houses built 1961-1975 (26%) and lowest in houses built 1985-1990 (4%).

CONCLUSION

To identify "risk buildings", it is necessary to adjust for ownership and population characteristics.

Indoor environment in dwellings, asthma, allergies, and sick building syndrome in the Swedish population: a longitudinal cohort study from 1989 to 1997

OBJECTIVES

To investigate changes of sick building syndrome (SBS) and different types of indoor exposures at home over an 8-year follow-up period (1989-1997), and onset of SBS symptoms in relation to size of residence town and education level.

METHODS

A random sample (0.1%) of the population in a 3-county region in Sweden, initially aged 20-65 years (n = 466). In total, 348 (75%) answered the postal follow-up questionnaire.

RESULTS

Water leakage during the last year had decreased from 11.2 to 4.8% visible indoor mould had decreased from 4.7 to 1.6%, and any sign of building dampness decreased from 16.1 to 9.5%. The prevalence of current smoking had decreased from 30 to 19%. Smokers at baseline reported more onset of SBS symptoms than non-smokers. Furthermore, remission from mucosal symptoms was less likely in subjects that were tobacco smoker. Subjects with any indoor painting during follow-up period reported more onset of SBS symptoms, and those with intermediate education level had more onset of skin symptoms.

CONCLUSION

Smoking and indoor painting could be predictors of new onset of SBS symptoms. Focus on indoor environment in Sweden the last decades may have resulted in environmental improvements in the dwellings, which can be beneficial both for the inhabitants and for the future public health.

Screening tools to estimate mold burdens in homes

OBJECTIVE

The objective of this study was to develop screening tools that could be used to estimate the mold burden in a home which would indicate whether more detailed testing might be useful.

METHODS

Two possible screening methods were considered for mold analysis: use of vacuum cleaner bag dust rather than the standard protocol dust samples and reducing the number of molds needed to be quantified resulting in the creation of an alternative mold burden scale.

RESULTS

Vacuum bag dust analysis placed the estimate of mold burden into the upper or lower half of the Environmental Relative Moldiness Index scale. Mold burdens estimated by only 12 species produced an index, the American Relative Moldiness Index, with a correlation of rho = 0.80 with the Environmental Relative Moldiness Index.

CONCLUSIONS

Two screening tools were developed for estimating the mold burden in homes.

Regional differences in residential environments and the association of dwellings and residential factors with the sick house syndrome: a nationwide cross-sectional questionnaire study in Japan

This study was conducted to clarify regional differences in residential factors and the association of those factors with dwellings having sick house syndrome (SHS) problems. The survey was conducted in six areas of northern and southern Japan. In terms of regional differences, dampness was not as severe in the dwellings in Sapporo as compared with that in areas in the south. SHS was defined using five categories of nasal, throat and respiratory, skin and general symptoms, which appeared frequently or not frequently and improved upon leaving the home. The dampness index was estimated by the sum of the presence of several indicators: condensation on the window panes and/or wall, visible mold growth, moldy odor, slow-drying wet towels in the bathroom, and water leakage. The dwellings where inhabitants showed any symptoms of SHS comprised 3.7% of all surveyed dwellings. We found significant associations between SHS and dampness index, odors, and stuffiness of the air. For dampness, the adjusted odds ratio (OR) increased with increased dampness index, adjusting for the age of the house, pets indoors, stuffiness of the air, and odors. These results showed an increased risk when several dampness indicators appeared simultaneously.

PRACTICAL IMPLICATIONS

To evaluate the associations of residential environments and Sick House Syndrome (SHS), this cross-sectional questionnaire study was conducted on 2297 dwellings in six areas in Japan from 2003 to 2004. The dwellings where inhabitants showed any of nasal, throat and respiratory, skin and general symptoms comprised 3.7% of all surveyed dwellings, and an increased risk for SHS was found when several dampness indicators, 'condensation', 'visible mold growth', 'moldy odor', 'slow drying wet towels in the bathroom' and 'water leakage', appeared simultaneously.

Low home ventilation rate in combination with moldy odor from the building structure increase the risk for allergic symptoms in children

There are consistent findings on associations between asthma and allergy symptoms and residential mold and moisture. However, definitions of 'dampness' in studies are diverse because of differences in climate and building construction. Few studies have estimated mold problems inside the building structure by odor assessments. In a nested case-control study of 400 Swedish children, observations and measurements were performed in their homes by inspectors, and the children were examined by physicians for diagnoses of asthma, eczema, and rhinitis. In conclusion, we found an association between moldy odor along the skirting board and allergic symptoms among children, mainly rhinitis. No associations with any of the allergic symptoms were found for discoloured stains, 'floor dampness' or a general mold odor in the room. A moldy odor along the skirting board can be a proxy for hidden moisture problem inside the outer wall construction or in the foundation construction. There are indications that such dampness problems increase the risk for sensitization but the interpretation of data in respect of sensitization is difficult as about 80% of the children with rhinitis were sensitized. Furthermore, low ventilation rate in combination with moldy odor along the skirting board further increased the risk for three out of four studied outcomes, indicating that the ventilation rate is an effect modifier for indoor pollutants.

PRACTICAL IMPLICATIONS

This study showed that mold odor at the skirting board level is strongly associated with allergic symptoms among children. Such odor at that specific place can be seen as a proxy for some kind of hidden moisture or mold problem in the building structure, such as the foundation or wooden ground beam. In houses with odor along the skirting board, dismantling of the structure is required for an investigation of possible moisture damage, measurements, and choice of actions. In homes with low ventilation in combination with mold odor along the skirting board, there was even a higher risk of health effects. This emphasizes the need for the appropriate remediation as this is an ever increasing problem in poorly ventilated houses that are damp.

Low tumor necrosis factor alpha levels and neutrophil counts in nasal lavage after mold exposure

BACKGROUND

The results of allergy tests against molds usually remain negative in patients with upper respiratory tract and conjunctival symptoms after microbial exposure in a water-damaged building. Most mold-exposed persons report nasal irritation. Immune mechanisms of the nasal symptoms have not been fully elucidated.

OBJECTIVE

To investigate local inflammatory responses after mold exposure in the upper respiratory tract and the feasibility of nasal lavage in diagnosing work-related exposure.

METHODS

Altogether, 26 mold-exposed and 20 nonexposed workers from the same hospital were selected for the present study. The work premises of the exposed workers had detectable moisture and microbial problems. All exposed workers and their nonexposed controls underwent clinical examination, laboratory tests to detect allergy to molds, and nasal lavage. Inflammatory cells and proinflammatory cytokines were measured in the nasal lavage fluid. Nasal lavages were performed again 6 months after a thorough renovation of the building.

RESULTS

In the nasal lavage, the neutrophil count and the level of tumor necrosis factor alpha in the exposed employees were lower, whereas the macrophage and epithelial cell counts were higher than in the control group. After the renovation, no difference was found in inflammatory response between the study group and the control group. The mean concentration of serum IgG to Stachybotrys chartarum was higher in the exposed workers.

CONCLUSIONS

These results suggest that exposure to toxin-producing microbial growth in a water-damaged building caused immunosuppression in nasal mucosa, leading to a decrease in neutrophil counts and tumor necrosis factor alpha levels. Nasal lavage is a suitable method for examining inflammatory responses in work-related mold exposure.

Occupational rhinitis in damp and moldy workplaces

BACKGROUND

Numerous studies confirm the association between exposure to indoor air dampness and molds and different health outcomes. Of these, upper respiratory tract problems are the most commonly reported work-related symptoms in damp indoor environments. The aim of this study was to describe a clinically investigated patient series with occupational rhinitis induced by molds.

METHODS

Nasal provocation test (NPT) with commercial fungal allergens was performed in 369 patients during 1995-2004 at the Finnish Institute of Occupational Health. Of these, 60 (16%) were positive. In addition to positive NPT, the diagnosis of occupational rhinitis was based on verified exposure to molds, work-related nasal symptoms, and clinical investigations. We wanted to review the patient files of these 60 patients retrospectively, and 56 patients gave their informed consent.

RESULTS

The mean age of the patients was 43.7 years (SD +/- 9.5). Fifty (89.3%) patients were women. In 23% of the patients, IgE-mediated allergy to molds could be established. Atopy significantly increased IgE sensitization to molds (OR, 10.3 [95% CI, 2.0-52.5]). The most common mold to induce occupational rhinitis was Aspergillus fumigatus. Exposure time was over 5 years in 63% of the patients. Association between the IgE sensitization to molds and exposure level was statistically significant (Fisher's exact test, p = 0.046).

CONCLUSION

This is the first clinically investigated series on occupational rhinitis in relation to a moldy environment. Based on our findings, we conclude that molds growing in conjunction with moisture damages can induce occupational rhinitis. IgE-mediated allergy to molds was not common. Atopy and significant exposure level increased IgE sensitization to molds. zri00508.

Dampness and mold in the indoor environment: implications for asthma

This article presents epidemiologic findings pertinent to asthma and asthma-like symptoms in relation to exposure to dampness/mold in homes, schools, and workplaces. With regard to specific agents found in damp indoor environments that may play a role in asthma, it concentrates on mold (used synonymously with fungi) and includes some findings on bacteria. The literature on asthma in relation to dust mite or cockroach allergens is not addressed.

Quality of indoor residential air and health

About 90% of our time is spent indoors where we are exposed to chemical and biological contaminants and possibly to carcinogens. These agents may influence the risk of developing nonspecific respiratory and neurologic symptoms, allergies, asthma and lung cancer. We review the sources, health effects and control strategies for several of these agents. There are conflicting data about indoor allergens. Early exposure may increase or may decrease the risk of future sensitization. Reports of indoor moulds or dampness or both are consistently associated with increased respiratory symptoms but causality has not been established. After cigarette smoking, exposure to environmental tobacco smoke and radon are the most common causes of lung cancer. Homeowners can improve the air quality in their homes, often with relatively simple measures, which should provide health benefits.

Healthy and safe school environment, Part II, Physical school environment: results from the School Health Policies and Programs Study 2006

BACKGROUND

As society continues to focus on the importance of academic achievement, the physical environment of schools should be addressed as 1 of the critical factors that influence academic outcomes. The School Health Policies and Programs Study (SHPPS) 2006 provides, for the first time, a comprehensive look at the extent to which schools have health-promoting physical school environment policies and programs.

METHODS

The Centers for Disease Control and Prevention conducts the SHPPS every 6 years. In 2006, computer-assisted telephone interviews or self-administered mail questionnaires were completed by state education agency personnel in all 50 states and the District of Columbia and among a nationally representative sample of school districts (n=424). Computer-assisted personal interviews were conducted with personnel in a nationally representative sample of elementary, middle, and high schools (n=992).

RESULTS

One third (35.4%) of districts and 51.4% of schools had an indoor air quality management program; 35.3% of districts had a school bus engine-idling reduction program; most districts and schools had a policy or plan for how to use, label, store, dispose of, and reduce the use of hazardous materials; 24.5% of states required districts or schools to follow an integrated pest management program; and 13.4% of districts had a policy to include green design when building new school buildings or renovating existing buildings.

CONCLUSIONS

SHPPS 2006 results can guide education and health agency actions in developing and implementing evidence-based tools, policies, programs, and interventions to ensure a safe and healthy physical school environment.