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Abstract
Abstract
Abstract The public health risk and economic impact of dampness and mold exposures was assessed using current asthma as a health endpoint. Individual risk of current asthma from exposure to dampness and mold in homes from W.J. Fisk, Q. Lei-Gomez & M.J. Mendell [(2007) Indoor Air17, 226–235], and asthma risks calculated from additional studies that reported the prevalence of dampness and mold in homes were used to estimate the proportion of US current asthma cases that are attributable to dampness and mold exposure at 21% (95% confidence internal 12–29%). An examination of the literature covering dampness and mold in schools, offices, and institutional buildings, which is summarized in the Appendix, suggests that risks from exposure in these buildings are similar to risks from exposures in homes. Of the 21.8 million people reported to have asthma in the USA, approximately 4.6 (2.7–6.3) million cases are estimated to be attributable to dampness and mold exposure in the home. Estimates of the national cost of asthma from two prior studies were updated to 2004 and used to estimate the economic impact of dampness and mold exposures. By applying the attributable fraction to the updated national annual cost of asthma, the national annual cost of asthma that is attributable to dampness and mold exposure in the home is estimated to be 2.1–4.8 billion). Analysis indicates that exposure to dampness and mold in buildings poses significant public health and economic risks in the USA. These findings are compatible with public policies and programs that help control moisture and mold in buildings.
... Mould poisons may kill humans with low immunity [10]. Indoor mould growth harms health and the economy [11]. Due to indoor mould, 4.6 million Americans have asthma, and the average cost of treatment is 3.5 billion dollars [11]. ...
... Indoor mould growth harms health and the economy [11]. Due to indoor mould, 4.6 million Americans have asthma, and the average cost of treatment is 3.5 billion dollars [11]. The interior decorating, materials, and building structures harmed by mould may be expensive [12]. ...
There are few literature evaluations that analyse the growing environment of indoor mould, despite its health risks and building management burden. This paper examines the most significant factors influencing indoor mould growth and risk levels through a literature review. It was discovered that relative humidity, temperature, time, and nutrients in the substrate were the most significant factors affecting the growth of moulds and that the development of the majority of mould species depended heavily on the relative humidity and temperature values. The optimal ranges for mould growth in terms of temperature and relative humidity are 30°C to 35°C and 95% to 99%, respectively. In order to prevent the growth of indoor mould, this review suggests that the indoor environment of future buildings should pay particular attention to the control of the thermal and humid environment, as well as the accumulation of nutrients and time within the interior of walls.
... Moisture control represents an important yet often overlooked aspect of healthy buildings, with research linking building dampness to significant health impacts (Table 6). Studies indicate that building moisture issues contribute to 21% of US asthma cases (Mudarri and Fisk 2007) while also causing various respiratory and non-respiratory symptoms (Koskinen et al. 1999). The economic burden through healthcare costs and lost productivity is substantial (Kielb et al. 2014), underlining the importance of effective moisture control strategies in building design. ...
... Exposure to dampness and mould increases the risk of newonset asthma. Our recommendations on the increased risk are supported by several studies that showed that indoor exposure to dampness and mould raises the risk for asthma development, ever diagnosed asthma, and current asthma [60,61,179,180]. 11 | Gaps in evidence for the impact of indoor air pollutants on asthma development and asthma-related outcomes and plans to address. ...
The EAACI Guidelines used the GRADE approach to evaluate the impact of major indoor air pollutants (dampness and mould, cleaning agents, volatile organic compounds and pesticides) on the risk of new‐onset asthma and on asthma‐related outcomes. The guideline also acknowledges the synergies among indoor air pollutants and other components of the indoor exposome (allergens, viruses, endotoxins). Very low to low certainty of evidence was found for the association between exposure to indoor pollutants and increased risk of new‐onset asthma and asthma worsening. Only for mould exposure there was moderate certainty of evidence for new‐onset asthma. Due to the quality of evidence, conditional recommendations were formulated on the risk of exposure to all indoor pollutants. Recommendations are provided for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management. For policymakers and regulators this evidence‐informed guideline supports setting legally binding standards and goals for indoor air quality at international, national and local levels. Asthma management counselled by the current EAACI guidelines can improve asthma‐related outcomes but community and governmental measures for improved indoor air quality are needed to achieve significant impact.
... This work has demonstrated the attributable risk for asthma associated with mold and dampness in houses is approximately 20% and associated with a considerable burden on the healthcare system. 23,24 Comprehensive remediation measures to reduce mold exposure as well as the underlying moisture conditions reduce respiratory symptoms and asthma morbidity. 25−28 In North America, the epidemiological studies linking mold and dampness and respiratory health in children began in communities that had been extensively studied for the impact of outdoor air pollution and health. ...
This chapter addresses mold and dampness in the built environment and mycotoxin exposure in developing countries.
... In residential housing, this has a considerable economic impact. 39,40 The allergens and other relevant biologically active compounds, including (1,3)-β-D-glucan, from damp building fungi are discussed in Chapter 24. ...
This chapter addresses the health concerns from bioerosols in non industrial and some industrial work environments
... The maximum attributable risk for asthma associated with mold and dampness in houses has been estimated at 20%. 23,24 Using a weight of evidence approach, comprehensive remediation measures to reduce mold exposure as well as the underlying moisture conditions reduced respiratory symptoms and asthma morbidity. [25][26][27] This position has been adopted by several prominent panels and health agencies worldwide. ...
This is a very detailed discussion on fungal metabolites, their measurement and health relevance in homes, non industrial and agriculture & forestry.
... Exposure of asthmatics to mold in housing costs $22.4 billion per year in the United States alone [1,2]. Waterdamaged and moldy homes are consistently associated with asthma, respiratory and allergic health outcomes, in both children and adults [3][4][5][6][7][8][9][10][11][12]. ...
Background
Increased risk of asthma and other respiratory diseases is associated with exposures to microbial communities growing in damp and moldy indoor environments. The exact causal mechanisms remain unknown, and occupant health effects have not been consistently associated with any species-based mold measurement methods. We need new quantitative methods to identify homes with potentially harmful fungal growth that are not dependent upon species. The goal of this study was to identify genes consistently associated with fungal growth and associated function under damp conditions for use as potential indicators of mold in homes regardless of fungal species present. A de novo metatranscriptomic analysis was performed using house dust from across the US, incubated at 50%, 85%, or 100% equilibrium relative humidity (ERH) for 1 week.
Results
Gene expression was a function of moisture (adonis2 p < 0.001), with fungal metabolic activity increasing with an increase in moisture condition (Kruskal–Wallis p = 0.003). Genes associated with fungal growth such as sporulation (n = 264), hyphal growth (n = 62), and secondary metabolism (n = 124) were significantly upregulated at elevated ERH conditions when compared to the low 50% ERH (FDR-adjusted p ≤ 0.001, log2FC ≥ 2), indicating that fungal function is influenced by damp conditions. A total of 67 genes were identified as consistently associated with the elevated 85% or 100% ERH conditions and included fungal developmental regulators and secondary metabolite genes such as brlA (log2FC = 7.39, upregulated at 100% compared to 85%) and stcC (log2FC = 8.78, upregulated at 85% compared to 50%).
Conclusions
Our results demonstrate that moisture conditions more strongly influence gene expression of indoor fungal communities compared to species presence. Identifying genes indicative of microbial growth under damp conditions will help develop robust monitoring techniques for indoor microbial exposures and improve understanding of how dampness and mold are linked to disease.
-X5AkW-U2mftBzktcaxDSrVideo Abstract
... In adult cases of CIRS, the incidence of nuclear scan positive gastroparesis approaches 5%. [76] reported that WDB account for 21% of all cases of asthma in the US. The pulmonary function tests used to diagnose repeated, reversible obstructive lung problems were not reported. ...
Evidence supports a cause-effect relationship between exposure to the air and dust in water-damaged buildings (WDBs) and a chronic inflammatory response syndrome (CIRS) that is linked to certain HLA haplotypes. CIRS-WDB is mediated by an over-reactive innate immune response to the toxins, antigens, and inflammagens found in the interior environment of WDBs. Dose-response relationships in this condition are neither linear nor threshold in nature; the immune response depends on multiple variables in the human host. For patients with CIRS, current methods of WDB investigation and remediation are often not sufficient to prevent relapse of symptoms with re-exposure. CIRS-WDB is a growing public health hazard best addressed by a team of experts in medicine with specialized training in CIRS-WDB, indoor air quality, remediation, and construction working together to develop a collaborative plan that ensures ongoing safe habitation. Assessments of human health effects before and after remediation are mandatory to ensure adequacy of remediation efforts. ______________________________________________________________________________ BACKGROUND
... This work has demonstrated the attributable risk for asthma associated with mold and dampness in houses is approximately 20% and associated with a considerable burden on the healthcare system. 23,24 Comprehensive remediation measures to reduce mold exposure as well as the underlying moisture conditions reduce respiratory symptoms and asthma morbidity. 25−28 In North America, the epidemiological studies linking mold and dampness and respiratory health in children began in communities that had been extensively studied for the impact of outdoor air pollution and health. ...
... A study of 16,190 people in Denmark, Estonia, Iceland, Norway, and Sweden revealed a prevalence of damp indoor environments of 18%, with a higher occurrence of respiratory symptoms and asthma among those living in damp housing [33]. Another study estimated that approximately 50% of residents of homes in the USA are at higher risk of experiencing respiratory symptoms due to exposure to dampness and/or mold in their homes [34]. The risk was not limited to homes but extended to schools, offices, and other institutional buildings. ...
Mold infestations in buildings pose significant challenges to human health, affecting both private residences and hospitals. While molds commonly trigger asthma and allergies in the immunocompetent, they can cause life-threatening diseases in the immunocompromised. Currently, there is an unmet need for new strategies to reduce or prevent mold infestations. Far-UVC technology can inactivate microorganisms while remaining safe for humans. This study investigates the inhibitory efficacy of far-UVC light at 222 nm on the growth of common mold-producing fungi, specifically Penicillium candidum, when delivered in low-dose on-off duty cycles, a configuration consistent with its use in real-world settings. The inhibitory effect of the low-dose duty cycles was assessed on growth induced by i) an adjacent spore-producing P. candidum donor and ii) P. candidum spores seeded directly onto agar plates. In both setups, the far-UVC light significantly inhibited both vertical and horizontal growth of P. candidum, even when the UV doses were below the Threshold Value Limit of 23 mJ/cm². These results suggest that far-UVC light holds the potential to improve indoor air quality by reducing or preventing mold growth, also when people are present.
... Therefore most studies about bioaerosols focus on their negative effects, for example on air quality (G� orny et al. 2002;Hasegawa, Yamasaki, and Horiguchi 2011;Yamamoto et al. 2012;Heo, Kim, and Lee 2014;Unterwurzacher et al. 2018), human health (Douwes et al. 2003;Liebers, Raulf-Heimsoth, and Br€ uning 2008;Kim, Kabir, and Jahan 2018), health risks, and disease development and prevention (Soler and Schlosser 2012;Viegas et al. 2015;Oteros et al. 2019). Bioaerosols also play an important role in damp buildings (Gunnbj€ ornsdottir et al. 2003;Mudarri and Fisk 2007), hospital hygiene concepts (Stockwell et al. 2019) and safety and security of pharmaceutical products as well as food (European Commission 2008;Masotti et al. 2019;Theisinger, De Smidt, and Lues 2021). The state of knowledge about these particles in the air around us is limited. ...
... The maximum attributable risk for asthma associated with mold and dampness in houses has been estimated at 20%. 23,24 Using a weight of evidence approach, comprehensive remediation measures to reduce mold exposure as well as the underlying moisture conditions reduced respiratory symptoms and asthma morbidity. [25][26][27] This position has been adopted by several prominent panels and health agencies worldwide. ...
Fungal metabolites and allergens, chemistry, mechanistic information, measurement and relevance in non-industrial workplaces including schools as well as homes and in agriculture
... In residential housing, this has a considerable economic impact. 39,40 The allergens and other relevant biologically active compounds, including (1,3)-β-D-glucan, from damp building fungi are discussed in Chapter 24. ...
Health effects of microbial contamination of non industrial workplaces
... This is because temperature played a dominant role in parameter A (Figure 3), and we observed that the effect of temperature on A might show a linear trend, so we used the Arrhenius-Davey secondary model to predict parameter A. Unlike the indoor environment field, previous studies have focused more on the maximum growth rate and lag time, with relatively less mathematical modeling for the maximum growth diameter A [47,53], except for Penggang Pei et al. [52]'s introduction of A in the Baranyi model, which was not used in his research. We believe that the maximum growth diameter A is equally important because, in indoor environments, the area of mold growth might be an important factor that affects the distribution of indoor mold aerosols [69]. Therefore, we also conducted secondary modeling for parameter A, and the model was found to have a good prediction ability (Adj.R 2 > 0.800). ...
A substantial body of evidence suggests that indoor mold exposure is a cause of allergic and respiratory diseases in humans. While models exist for assessing the risk of mold growth on building materials, few study the characteristics of mold growth after germination. This study conducted mold growth experiments in a constant temperature chamber, using four temperature settings of 15, 20, 25 and 30 • C, and three relative humidities of 56 to 61%, 75 to 76% and 83 to 86%. A mold growth prediction model was established using temperature and relative humidity. The accuracy of the model was verified by comparing the sampling and the predicted values in a laboratory environment. The results indicated that reducing the environmental temperature and relative humidity could significantly inhibit the growth of mold, although the inhibitory effects varied. Temperature might play a more critical role. At higher temperatures (25 • C and 30 • C), the growth rate and lag time of mold tended to be consistent and there were differences in the maximum diameter. In the predictive model, the polynomial secondary model for the maximum growth rate and lag time and the Arrhenius-Davey secondary model for the maximum diameter (A) had good predictive effects (Adj.R 2 > 0.850). It is speculated that temperature is the key factor affecting the maximum growth diameter of mold. The mold growth prediction model could better predict the growth of mold in actual environments without wind Adj.R 2 > 0.800), but the accuracy of the model decreased under windy conditions (wind velocity < 1 m/s). The mold growth predictive model we established could be used to predict the growth characteristics of mold in windless environments. It also provides control suggestions for the regulation of temperature and relative humidity in indoor environments, supporting indoor thermal environment management and pollutant control, and ensuring indoor human health.
... According to a systematic review, several factors contribute to the contamination of buildings, including dampness, building components, and occupant behavior [6]. These factors, in combination with genetic predisposition of the occupants, contribute to development of respiratory disease and asthma morbidity and mortality [7][8][9]. In combination with the increased incidence of mucormycosis in some countries during the COVID-19 global pandemic, there is a great effort to understand the impact of chronic, repeated fungal exposure [10]. ...
Aspergillus versicolor is ubiquitous in the environment and is particularly abundant in damp indoor spaces. Exposure to Aspergillus species, as well as other environmental fungi, has been linked to respiratory health outcomes, including asthma, allergy, and even local or disseminated infection. However, the pulmonary immunological mechanisms associated with repeated exposure to A. versicolor have remained relatively uncharacterized. Here, A. versicolor was cultured and desiccated on rice then placed in an acoustical generator system to achieve aerosolization. Mice were challenged with titrated doses of aerosolized conidia to examine deposition, lymphoproliferative properties, and immunotoxicological response to repeated inhalation exposures. The necessary dose to induce lymphoproliferation was identified, but not infection-like pathology. Further, it was determined that the dose was able to initiate localized immune responses. The data presented in this study demonstrate an optimized and reproducible method for delivering A. versicolor conidia to rodents via nose-only inhalation. Additionally, the feasibility of a long-term repeated exposure study was established. This experimental protocol can be used in future studies to investigate the physiological effects of repeated pulmonary exposure to fungal conidia utilizing a practical and relevant mode of delivery. In total, these data constitute an important foundation for subsequent research in the field.
... A asma é estimada a atingir 7,72% dos brasileiros, conforme supracitado. 27,28,29,30 que buscam estimar a parcela atribuível a um fator de exposição em um determinado desfecho de interesse e, a partir desse valor, estimar os impactos econômicos e na qualidade de vida devido à determinada exposição. Mudarri e Fisk 28 utilizaram esse conceito para avaliar os impactos econômicos e de saúde pública da exposição a mofo e umidade nos Estados Unidos, determinando que a fração atribuível à exposição no desfecho de interesse, asma, é de 21%, representando aproximadamente 4,6 milhões de casos naquele país. ...
Introdução: A asma é uma das doenças não comunicáveis mais comuns no mundo. No Brasil, no ano de 2019, ela foi responsável por aproximadamente 79,9 mil internações somente nos sistemas de saúde pública e complementar. O mofo residencial é um fator de risco reconhecido na prevalência de asma. Objetivos: Analisar a parcela atribuível à exposição a mofo e/ou umidade residencial nos casos de asma e seus custos diretos e indiretos no Brasil. Métodos: Foi estimada a prevalência da asma e da exposição a mofo/umidade residencial no Brasil em diferentes períodos usando dados de várias fontes. Em seguida, analisou os custos de internações no Sistema Único de Saúde do Brasil. Calculou-se a fração atribuível à exposição a mofo/umidade residencial nos casos e custos de asma no país, utilizando o Teorema de Bayes. Resultados: Os dados da pesquisa revelam que os custos diretos com asma atribuíveis à exposição a mofo e/ou umidade residenciais em 2019 foram de R 109,9 milhões, considerando somente os dados das redes pública e complementar do sistema de saúde brasileiro. Ainda foi possível analisar que 2,4 milhões de casos de asma no Brasil podem ser atribuídos à exposição a mofo e/ou umidade habitacional. Conclusão: O provimento de habitação adequada sem o fator de exposição para populações vulneráveis tem o potencial de reduzir os custos diretos e indiretos no sistema de saúde e, além disso, propiciar melhoria na qualidade de vida de aproximadamente 2,4 milhões de pacientes asmáticos no país.
... 30,31 Specific immunoglobulin E (IgE) hypersensitivity is one of the main health problems caused by poor IAQ in damp homes. 32,33 Common indoor molds such as Penicillium spp and Aspergillus spp can induce IgE-mediated hypersensitivity, however, hypersensitivity pneumonitis, a type III-mediated immune response, can also occur when buildings are contaminated with bacteria and molds. 34 Allergic bronchopulmonary aspergillosis and allergic fungal sinusitis occur when these respiratory tracts colonized by molds elicit in situ allergic inflammatory reactions. ...
Our climate has measurably changed over the years, which could be the greatest health threat of the twenty-first century.
Climate change is affecting our ecosystems with consequent direct and indirect impacts on our patients with allergic and respiratory diseases.
Indoor air quality is a major concern worldwide due to its adverse effects on human health, which has the greatest impact on children and the elderly living in the lower socioeconomic strata of the population with allergic rhinitis, asthma, and chronic obstructive pulmonary disease.
Lifestyle adjustments and the implementation of effective evidence-based regulations can mitigate continued climate-related increases in indoor air pollution and consequently reduce the onset and progression of respiratory diseases
... Coincidently, indoor air pollutants are associated with the incidence, spread, and mortality rates of COVID-19 disease (Domínguez-amarillo et al., 2020;Zoran et al., 2020;Wang & Li, 2021). In addition, biological factors such as fungi and bacteria are detected in indoor air and dust (Meklin et al., 2002), which may contribute to health issues (Mudarri & Fisk, 2007). A systematic analysis indicated that the indoor bacteria varied from 72.5 to 7500 CFU/m 3 , with a median value of 1000 CFU/m 3 , and the indoor concentration of fungi varied from 12 to 9730 CFU/m 3 , with a median value of 526 CFU/m 3 (Guo et al., 2020). ...
Indoor air quality can vary significantly from place to place, and it has been shown to play a critical role in respiratory diseases. This study aims to investigate the microbial communities present in indoor water cultures using metagenomic analysis. After 45 days of culturing, we collected organisms from three water samples: sterilized laboratory tap water (Al02), non-sterilized laboratory tap water (Al03), and water from the Ohio River near the campus (Al04). We isolated and purified the genomic DNA and then constructed genomic DNA libraries. Subsequently, we sequenced and analyzed the genomic DNA fragments within these libraries. The study identified a total of 1,123,463 open reading frames (ORFs). Among these ORFs, 4.76% were shared between Al02 and Al03, 3.09% were shared between Al03 and Al04, and 1.67% were shared between Al02 and Al04. The ORFs were mainly associated with metabolism, environmental information processing, and genetic information processing. Enzyme analysis revealed that the identified ORFs were mainly associated with glycosyl transferases, glycoside hydrolases, carbohydrate-binding molecules, carbohydrate esterases, and auxiliary activities. The most abundant phylum identified was Proteobacteria, and Chlorophyta was also a significant phylum in all three samples.
... Hygrothermal analysis is commonly used to model the performance of external wall assemblies before construction, helping to mitigate moisture-related issues including microbial growth, such as mould [1]. These issues have been linked to various health concerns including asthma, allergic rhinitis, lung cancer, and skin disorders [2][3][4][5]. ...
Probabilistic methods can be used to account for uncertainties in hygrothermal analysis of building envelopes. This paper presents methods for robust mould reliability analysis and identification of critical parameters. Mould indices are calculated by probabilistic hygrothermal analysis, followed by the application of the "Finnish mould growth model." To increase the robustness of the mould growth analysis, a random forests metamodel is first trained on the dataset and then used to expand the number of simulations. Finally, the reliability is calculated based on the probability of exceeding a given maximum mould index limit state. Critical parameters are identified through a sensitivity analysis based on linear and non-linear dependencies between inputs and maximum mould index. The methods are demonstrated by analysing three external wall assemblies. In conclusion, the mould reliability analysis method helps to assess the robustness of the hygrothermal analysis and mould assessment by investigating the influence of hygrothermal variables' uncertainties on the maximum mould index. By combining a metamodel with probabilistic analysis, it is possible to significantly reduce the amount of time required to evaluate a large number of scenarios.
... The literature highlights the overall negative impact on the health of users through the term "sick building syndrome (SBS)", which is the negative manifestation of the population working, partially or totally, inside buildings affected by microorganism deposits, due to the degradation of indoor air quality through contamination with spores and toxins [1,[4][5][6]. The most common mycotoxins identified in indoor air and the bodies of the population living in the contaminated environment are produced by moulds such as Cladosporium, Acremonium, Alternaria, Periconia, Curvularia, Rhizopus, Mucor, Streptomyces, Penicillium, Aspergillus, Stachybotrys, Fusarium, and Myrothecium [7][8][9][10], known to be genotoxic, immunotoxic, hepatotoxic, mutagenic; and potentially carcinogenic mycotoxins are ochratoxin [7] (OCT), aflatoxin B1 [9] and trichothecene [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. ...
Worldwide, the need for thermal insulation materials used to increase the energy performance of buildings and ensure indoor thermal comfort is constantly growing. There are several traditional, well-known and frequently used thermal insulation materials on the building materials market, but there is a growing trend towards innovative materials based on agro-industrial waste. This paper analyses the performance of 10 such innovative thermal insulation materials obtained by recycling cellulosic and/or animal waste, using standardised testing methods. More precisely, thermal insulation materials based on the following raw materials were analysed: cellulose acetate, cigarette filter manufacturing waste; cellulose acetate, cigarette filter manufacturing waste and cigarette paper waste; cellulose acetate, waste from cigarette filter manufacturing, waste cigarette paper and waste aluminised paper; cellulose from waste paper (two types made by two independent manufacturers); wood fibres; cellulose from cardboard waste; cellulose from waste cardboard, poor processing, inhomogeneous product; rice husk waste and composite based on sheep wool, recycled PET fibres and cellulosic fibres for the textile industry. The analysis followed the performance in terms of thermal insulating quality, evidenced by the thermal conductivity coefficient (used as a measurable indicator) determined for both dry and conditioned material at 50% RH, in several density variants, simulating the subsidence under its own weight or under various possible stresses arising in use. The results showed in most cases that an increase in material density has beneficial effects by reducing the coefficient of thermal conductivity, but exceptions were also reported. In conjunction with this parameter, the analysis of the 10 types of materials also looked at their moisture sorption/desorption capacity (using as a measurable indicator the amount of water stored by the material), concluding that, although they have a capacity to regulate the humidity of the indoor air, under low RH conditions the water loss is not complete, leaving a residual quantity of material that could favour the development of mould. Therefore, the impact on indoor air quality was also analysed by assessing the risk of mould growth (using as a measurable indicator the class and performance category of the material in terms of nutrient content conducive to the growth of microorganisms) under high humidity conditions but also the resistance to the action of two commonly encountered moulds, Aspergillus niger and Penicillium notatum. The results showed a relative resistance to the action of microbiological factors, indicating however the need for intensified biocidal treatment.
... Our approach here is that the probability of the health adverse state representing mould is provided by the mould reliability analysis. This constitutes a normative approach adding to the medical literature available descriptive approaches, e.g. in [19,20]. The probability of health problem consequences then is calculated with the mould reliability analysis providing the health-adverse state and the from the odds ratios in medical literature derived conditional probabilities ( | ) ...
Common solutions for building energy-efficient buildings constitute e.g., double-glazed windows, airtight building envelopes and highly insulated walls. These solutions may improve the indoor environment/comfort but can also lead to adverse effect, e.g., mould at the surface of the construction components and consequently human health problems. With this study, a mould risk assessment including health consequences, a decision analysis and their adaptation to different types of building envelopes are developed. Within the frame of a mould risk and decision analysis, a physics and biology-based mould reliability analysis is combined with a medical science-based health occurrence and consequence model on an interdisciplinary basis. For the minimization of the expected consequences, an Inutility Decision Analysis (IDA) including an objective function is introduced and applied to a case study. An external wooden frame wall in a residential building is analysed and optimized with IDA quantitatively modelling the expected life cycle costs and the mould induced health risk of design alternatives. The calculation of the probability of mould occurrence is based on hygrothermal and mould reliability analysis. The health consequences are calculated with the conditional probability of asthma as inferred from the odds ratio in medical literature. The costs of choosing a type of external wall, are modelled based on the costs of the materials and works related to assembling them. The design alternative with the minimum aggregated risks and expected cost, i.e., expected inutility is selected. Within the assumptions of the example, it is demonstrated that mould health consequences constitute an important part of the expected inutilities.
... Respiration of mould can lead to health problems, such as fungal respiratory infections such as Aspergillosis, Histoplasmosis and Coccidioidomycosis [79]. Damp and mouldy housing accounts for a substantial proportion of the burden of disease, as shown in the U.S. [91] and New Zealand [92]. Improving the thermal quality of housing to eliminate damp and mould and producing a comfortable temperature through the house had a positive impact on the health of the residents [68], and substantially reduced total hospitalisation costs and potentially improved quality of life [92]. ...
Researchers across disciplines are increasing attention to cold housing environments. Public health, environmental and social sciences, architecture, and engineering each define and measure cold housing environments differently. Lack of standardisation hinders our ability to combine evidence, determine prevalence, understand who is most at risk––and to formulate policy responses. We conducted a systematic, cross-disciplinary review of literature to document the measures used. We examined benefits and limitations of each approach and propose a conceptualisation of cold housing: where temperature is too low to support optimal health and wellbeing of inhabitants, measured using one or a combination of economic, ‘objective’, or subjective approaches. More accurate data on home temperatures for all population groups, combined with an understanding of factors leading to cold homes, will enable appropriate policy response to reduce adverse health effects and costs. Policies targeting better building standards and energy subsidies both improve temperature conditions in housing environments.
... This poses a significant risk to public health and the American economy as well elsewhere in the world. Since dampness and mould growth have a significant impact on the health of Americans, the occurrence of damp damage and mould growth in new and older buildings must be controlled (19). ...
Objectives:
Indoor air toxicity is of major public health concern due to the increase in humidity-induced indoor mould exposure and associated health changes. The objective is to present evidence for the causality of health threats and indoor mould exposure.
Methods:
PubMed search on the following keywords: dampness, mould, indoor air quality, public health, dampness, and mould hypersensitivity syndrome, sick building syndrome, and building-related illness as well as information from the health authorities of Bavaria and North Rhine-Westphalia, the Center of Disease Control (CDC), World Health Organisation (WHO), and guidelines of professional societies.
Results:
The guidelines of professional societies published in 2017 are decisive for the assessment of the impact of mould pollution caused by moisture damage on human health and for official regulations in Germany. Until 2017, a causal connection between moisture damage and mould exposure could usually only be established for pulmonary diseases. The health risk of fungal components is apparent as documented in the fungal priority pathogens list (FPPL) of the WHO. Since 2017, studies, especially in Scandinavia, have proved causality between moisture and mould exposure not only for pulmonary diseases but also for extrapulmonary diseases and symptoms. This was made possible by new test methods for determining the toxicity of fungal components in indoor air. Environmental medical syndromes, e.g., dampness and mould hypersensitivity syndrome (DMHS), sick building syndrome (SBS), building-related symptoms (BRS), and building-related illness (BRI), and fungal pathogens, e.g., Aspergillus fumigatus, pose a major threat to public health.
Conclusion:
There is evidence for the causality of moisture-induced indoor moulds and severe health threats in these buildings. According to these findings, it is no longer justifiable to ignore or trivialize the mould contamination induced by moisture damage and its effects on pulmonary and extrapulmonary diseases. The health and economic implications of these attitudes are clear.
... According to previous studies, many fungi grow indoors as mold where moisture is present. Some of these fungi can cause toxic reactions and may lead to infections in susceptible individuals and excessive mold growth can contribute to respiratory illness and infections [15,16]. ...
Objectives: Shopping malls are fast becoming one of the most visited public spaces globally. However, information on the possible environmental conditions in relation to health hazards in shopping malls is poorly documented in developing countries. This study assessed the sanitary conditions, waste management, safety measures and sources of air pollution associated with selected shopping malls in Nigeria.
Study Design: a descriptive cross-sectional study design was adopted using a comparative approach.
Methods: Three shopping malls (Mall Q, Mall R, and Mall S) in urban areas in Ibadan, Oyo State, Nigeria, were selected using convenience sampling technique. Three major shopping malls were selected using convenience sampling technique. Fifty seven, thirty five, and twenty nine stores were sampled in Mall Q, Mall R, and Mall S respectively. Direct on-site built environment and sanitary conditions of shopping malls were assessed using an observational checklist.
Results: It was observed that all the selected shopping malls had air vents that were free from dust, unbroken walls, and emergency exits, although mold growths were observed on the walls and ceilings of Mall Q and Mall R. Toilet facilities were present and functional across all the shopping malls. Waste management facilities were available across the shopping malls with the absence of overfilled waste bins as regular emptying of the waste bins was a routine. Also, various safety measures and equipment were utilized across all the shopping malls, but safety signals and smoke detectors were absent in Mall R. Furthermore, Mall R and S were 5 m within the proximity of major roads, parking lots and public drainage channels.
Conclusions: These findings reveal a need for improvement in the hygiene and sanitary conditions within shopping malls. Hence, there should be periodic environmental monitoring, and proper housekeeping practices should be encouraged in shopping malls in Nigeria.
... Bien que le bilan annuel Net ZEB soit un indicateur de la performance énergétique du bâtiment, il n'est pas suffisant pour caractériser pleinement les Net ZEBs (Sartori et al., 2012). En effet, les échanges d'énergie sur des échelles de temps plus courtes (mensuelles, journalières, horaires, etc.) sont importants étant donné que le facteur limitant est souvent la puissance maximale pouvant être importée ou exportée (Gunnbjörnsdóttir et al., 2006;Institut National de Santé Publique du Quebec, 2002;Mendell et al., 2011;Mudarri & Fisk, 2007;WHO, 2009 (Nejat et al., 2015). Ce polluant est devenu prioritaire depuis quelques années du fait de son lien étroit avec la respiration humaine et le renouvellement de l'air (ANSES, 2013). ...
La performance d'une maison ne doit pas être mesurée uniquement en fonction de sa consommation et de sa production d'énergie. Le niveau de confinement, la QAI et le confort doivent également être pris en compte pour assurer le bien-être des occupants. En effet, il existe dans la littérature un grand nombre d'indicateurs de performance de bâtiments basés sur différents paramètres en fonction des informations à obtenir. Le calcul de la plupart de ces indicateurs est ambigu car il ne précise pas clairement les lieux et périodes de mesure, le pas de temps, la prise en compte d’un scenario d’occupation ou même les valeurs limites à ne pas dépasser. L'absence de consensus sur les indicateurs de performance à utiliser et sur la manière de les calculer rend difficile la comparaison des maisons. Cette thèse a pour objectif principal de proposer un référentiel robuste d’indicateurs de performance qui peut être utilisé à la fois dans la phase de conception et pendant la phase d'occupation du logement. Ces indicateurs seront principalement calculés par rapport à de paramètres facilement mesurables à l’aide de sondes installées dans les bâtiments connectés, à savoir, la consommation électrique, la température, l’humidité et les concentrations de CO2, de COVT, de HCHO et de PM2,5.Pour cela, la méthodologie de travail cherchera à :•Inventorier l’ensemble des indicateurs basés sur un paramètre unique existants dans la littérature et les valeurs de référence correspondantes.•Identifier le pas de temps adéquat pour la mesure de chaque paramètre.•Expertiser la sensibilité des indicateurs en lien avec le scénario d’occupation afin de définir les informations nécessaires à leur utilisation.•Identifier les indicateurs les plus adaptés pour décrire les conditions à l’intérieur d’un logement à partir des mesures à disposition.•Evaluer la variabilité saisonnière et pluriannuelle des résultats des indicateurs pour ainsi définir le temps d’observation minimum qui permet d’obtenir une information suffisante pour évaluer la performance d’un bâtiment.•Et enfin, proposer un référentiel opérationnel, composé d’une sélection des différents indicateurs précédemment discutés, accompagné d’un ensemble de recommandation pour son utilisation optimale.
Background: Asthma is one of the most common non-communicable diseases in the world. In Brazil, from 2017 to 2019, it was responsible for approximately 260 thousand hospitalizations, with R$ 149.3 million as direct costs and more than 817 thousand days of hospitalizations. Residential mold is an associated risk factor. Objective: Calculate cases of asthma attributable to the exposure to residential mold in Brazil. Methods: A meta-analysis was performed with studies from 2014 to 2019 selected by a systematic review in the Web Of Science and United States National Library of Medicine (PubMed) databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Residential mold is the exposure factor and asthma the outcome of interest. Quality analysis and publication bias followed the protocols of the Joanna Briggs Institute. Results: An association between residential mold and asthma was identified with a single odds ratio of 1.525 and a 95% confidence interval between 1.385 and 1.679. The fraction of asthma cases in Brazil attributable to exposure to residential mold was estimated to be 16.76%, which may result in 13,383 cases and 42,904 days of hospitalizations in 2019 in the public and complementary networks of the Brazilian health system. Conclusions: The study suggests that the mitigation of this risk factor could lead to a lower incidence of this outcome.
Few studies assessed the long-term changes in the prevalence of indoor damp indicators in residences. In this paper, we tried to clarify nationwide spatial-temporal distributions of the prevalences of damp indicators in residences in the past four decades in China and compared the prevalences in other countries. A systematic review was conducted in three Chinese-language databases and two English-language databases from January 1980 to December 2020 according to the guidelines of PRISMA (preferred reporting items for systematic review and meta-analysis). After reviewing 5580 documents, 86 articles that provided specific data were retained for the review of prevalences of damp indicators in residences. Windowpane condensation was the most common damp indicator in residences (averaged: 34.1%, 95% CI: 28.1–40.1), followed by damp clothing and/or bedding (26.5%, 95% CI: 22.0–31.0), mouldy odour (13.3%, 95% CI: 10.4–16.2), water damage (12.5%, 95% CI: 8.6–16.5), visible mould spots (12.2%, 95% CI: 8.7–15.7) and visible damp stains (11.8%, 7.1%–16.5%) in dwellings in China. In the past four decades, increasing trends of window pane condensation prevalences and mouldy odour were noted and trend was then declined after 2010, whereas prevalences of water damage and visible damp stains were generally shown to produce decreasing trends in the surveys. Our findings provide comprehensive data for the evaluation of indoor damp indicators in residences in China.
Introduction: Exposure to dampness and mold in houses can lead to health problems among residents. Objective: To assess the face and content validity of the "Dampness and Mold Assessment Tool. General Buildings" instrument, proposed by the Centers for Disease Control and Prevention - National Institute for Occupational Safety and Health, for use in Spanish-speaking Latin American contexts. Materials and Methods: A face and content validation study was conducted through expert evaluation using the Delphi method. The Content Validity Index (CVI) was calculated for clarity, coherence, sufficiency, and relevance, as well as the level of agreement among raters. Results: A total of 20 expert evaluators participated, with an average of 18.5 ± 9.09 years of experience; 50% held doctoral degrees, and the other 50% held master’s degrees. The CVI scores were above 0.75 for all items, except for "room/area type" which had a CVI of 0.65. Agreement among experts was statistically significant (p < 0.05) except for "room/area type" (p = 0.055). Adjustments to the instrument were made based on the evaluators' recommendations. Discussion: This study is one of the first to validate this instrument, with potential for adaptation to various settings beyond residential, including hospitals, educational institutions, and workplaces. Conclusion: The face and content validation process enabled the development of an instrument for assessing dampness and mold damage in Spanish-speaking Latin American settings, generating a semi-quantitative indicator. This tool is recommended for use in home visits and research to support data on factor validity, Rasch analysis, and reliability in its application.
Background:
Increased risk of asthma and other respiratory disease is associated with exposures to microbial communities growing in damp and moldy indoor environments. The exact causal mechanisms remain unknown, and occupant health effects have not been consistently associated with any species-based mold measurement methods. We need new quantitative methods to identify homes with potentially harmful fungal growth that are not dependent upon species. The goal of this study was to identify genes consistently associated with fungal growth and associated function under damp conditions for use as potential indicators of mold in homes regardless of fungal species present. A de novo metatranscriptomic analysis was performed using house dust from across the US, incubated at 50%, 85%, or 100% equilibrium relative humidity (ERH) for one week.
Results:
Gene expression was a function of moisture (adonis2 p<0.001), with fungal metabolic activity increasing with increase in moisture condition (Kruskal-Wallis p=0.003). Genes associated with fungal growth such as sporulation (n=264), hyphal growth (n=62) and secondary metabolism (n=124) were significantly upregulated at elevated ERH conditions when compared to the low 50% ERH (FDR-adjusted p≤0.001, log2FC≥2), indicating that fungal function is influenced by damp conditions. A total of 67 genes were identified as consistently associated with the elevated 85% or 100% ERH conditions and included fungal developmental regulators and secondary metabolite genes such as brlA (log2FC=7.39, upregulated at 100% compared to 85%) and stcC (log2FC=8.78, upregulated at 85% compared to 50%).
Conclusions:
Our results demonstrate that moisture conditions more strongly influence gene expression of indoor fungal communities compared to species presence. Identifying genes indicative of microbial growth under damp conditions will help develop robust monitoring techniques for indoor microbial exposures and improve understanding of how dampness and mold is linked to disease.
People who suffer from asthma can have difficulty breathing after they are exposed to normally harmless substances in the air, such as pollen, dust, smoke, and pet dander. Some people experience a worsening of their asthma symptoms after a thunderstorm, and data tell us that climate change is making asthma more of a problem. But how do weather and climate events make it hard for some people to breathe? Asthma happens when the body’s immune system mistakes airborne particles for dangerous invaders and tries to fight them. It seems that climate change is increasing the amounts of air pollution, pollen, and mold in the air. The more of these triggers people breathe in, the greater the risk of asthma. In this article, we will explain how asthma happens, how climate change is making it worse, and what we can all do to help.
Mold infestations in buildings pose significant challenges to human health, affecting both private residences and hospitals. While molds commonly trigger asthma and allergies in the immunocompetent, they can cause life-threatening diseases in the immunocompromised. Currently, there is an unmet need for new strategies to reduce or prevent mold infestations. Far-UVC technology can inactivate microorganisms while remaining safe for humans. This study investigates the inhibitory efficacy of far-UVC light at 222 nm on the growth of common mold-producing fungi, specifically Penicillium candidum, when delivered in low-dose on-off duty cycles, a configuration consistent with its use in real-world settings. The inhibitory effect of the low-dose duty cycles was assessed on growth induced by i) an adjacent spore-producing P. candidum donor and ii) P. candidum spores seeded directly onto agar plates. In both setups, the far-UVC light significantly inhibited both vertical and horizontal growth of P. candidum, even when the UV doses were below the Threshold Value Limit of 23 mJ/cm2. These results suggest that far-UVC light holds the potential to improve indoor air quality by reducing or preventing mold growth, also when people are present.
Abstract Allergic airway disease (AAD) is a collective term for respiratory disorders that can be exacerbated upon exposure to airborne allergens. The contribution of fungal allergens to AAD has become well established over recent years. We conducted a comprehensive review of the literature using Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines to better understand the mechanisms involved in the allergic response to fungi in airway epithelia, identify knowledge gaps and make recommendations for future research. The search resulted in 61 studies for final analysis. Despite heterogeneity in the models and methods used, we identified major pathways involved in fungal allergy. These included the activation of protease‐activated receptor 2, the EGFR pathway, adenosine triphosphate and purinergic receptor‐dependent release of IL33, and oxidative stress, which drove mucin expression and goblet cell metaplasia, Th2 cytokine production, reduced barrier integrity, eosinophil recruitment, and airway hyperresponsiveness. However, there were several knowledge gaps and therefore we recommend future research should focus on the use of more physiologically relevant methods to directly compare key allergenic fungal species, clarify specific mechanisms of fungal allergy, and assess the fungal allergy in disease models. This will inform disease management and future interventions, ultimately reducing the burden of disease.
The analysis of heat, air, and moisture (H.A.M.) transport for building envelopes are known to be highly dependent on climate loads and air infiltration rates. Moisture content within the assembly is often a key H.A.M. analysis outcome to assess risk and transport behavior. ASHRAE Standard 160-2016 states that building envelope H.A.M. analysis should be done using moisture design reference data or using a minimum of 10 consecutive years of weather. While there has been progress and methods for selecting or designing moisture reference years there has been a lack of study in the impact of multi-year (particularly 10-year) weather scenarios on simulation results in comparison to reference year simulations. This paper presents research using stochastic 1, 2, and 10-year weather data and air infiltration rates to study the range of simulated moisture content outcomes for four wall assemblies in Philadelphia and compares these to the outcomes when using reference years. Results from the study show that air infiltration, starting month, and multi-year duration have significant impacts on simulated moisture content, mold, and corrosion analysis results. Regression analysis using annual averages of climate input parameters did not yield useable models for selecting weather years, however an estimated mold index value using outdoor climate data may be useful in selecting weather years with varying starting months for mold growth assessment.
Asthma and related factors were assessed by mailed questionnaires among 2041 young adult participants in a smoking prevention project in California in 1993. Hispanics had lower prevalence of physician-reported asthma when compared to blacks and whites. Blacks were significantly more likely to be hospitalized or visit emergency rooms because of asthma or wheezing. After adjusting for sex, race, and educational level, family history of asthma was strongly associated with subjects' asthma (odds ratio = 3.1, 95% CI: 2.4-4.3 for physician-reported asthma; OR = 3.3, 95% CI: 2.4-4.5 for current asthma). Exposure to parental smoking (both parents smoked more than half a pack of cigarettes a day) during childhood (reported when participants were in grade 7) was significantly associated with physician-reported asthma (OR = 2.9, 95% CI: 1.6-5.6) and current asthma (OR = 3.3, 95% CI: 1.7-6.4). The study also found that self-reported mold growth at home was significantly associated with asthma (OR = 2.0, 95% CI: 1.2-3.2). After adjusting for cigarette smoking and demographic variables, use of crack cocaine was marginally significantly associated with current asthma (OR = 2.3, 95% CI: 1.0-5.2), but not with physician-reported asthma (OR = 1.5, 95% CI: 0.7-3.3).
This study investigated two schools, one of which had previous mold problems. Pupils aged 6 to 13 yr were investigated using a questionnaire on symptoms and a skin prick test. The amount of airborne (1--> 3)-beta-D-glucan was measured in the classrooms. The levels were significantly higher in the problem school than in the control school (15.3 versus 2.9 ng/m3). The extent of respiratory as well as general symptoms was higher among the pupils in the problem school. Among the atopics, the extent of symptoms of dry cough, cough with phlegm, and hoarseness was similar to the nonatopics in the control school, but significantly higher in the problem school. The results suggest that (1--> 3)-beta-D-glucan, either by itself or as an indicator of molds, is a risk indicator of airways inflammation.
To evaluate dose-response relationships between airway inflammation/systemic symptoms and dampness exposure, we conducted a self-reported questionnaire study on risk factors among 1237 employees in 19 air-conditioned office buildings in the Taipei area. The odds ratio for eye irritation was 1.34 when either stuffy odor or mold was present in the buildings. The odds ratio increased to 1.72 when both stuffy odor and mold were present, to 3.14 when water damage was also present, and to 5.03 when four dampness exposure factors were present. Dampness in the building had a dose-response effect on eye irritation, cough, and lethargy/fatigue.
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-α (TNF-α) 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-α 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.
The association between home dampness and lower respiratory symptoms in children has been well documented. Whether fungal exposures contribute to this association is uncertain. In a prospective birth cohort of 499 children of parents with asthma/allergies, we examined in-home fungal concentrations as predictors of lower respiratory illnesses (LRI) (croup, pneumonia, bronchitis, and bronchiolitis) in the first year. In multivariate analyses, we found a significant increased relative risk (RR) between LRI and high levels (more than the 90th percentile) of airborne Penicillium (RR = 1.73, 95% confidence interval [CI], 1.23, 2.43), dust-borne Cladosporium (RR = 1.52; CI, 1.02, 2.25), Zygomycetes (RR = 1.96; CI, 1.35, 2.83), and Alternaria (RR = 1.51; CI, 1.00, 2.28), after controlling for sex, presence of water damage or visible mold/mildew, born in winter, breastfeeding, and being exposed to other children through siblings. In a multivariate analysis, the RR of LRI was elevated in households with any fungal level at more than the 90th percentile (RR = 1.86; CI, 1.21, 2.88). Exposure to high fungal levels increased the risk of LRI in infancy, even for infants with nonwheezing LRI. Actual mechanisms remain unknown, but fungi and their components (glucans, mycotoxins, and proteins) may increase the risk of LRI by acting as irritants or through increasing susceptibility to infection.
We conducted a 1-year epidemiologic study in Boston, Massachusetts, beginning May 1997, to examine the associations between environmental factors and office workers' health. We recruited 98 subjects (81 females and 17 males) in 21 offices in four office buildings. We conducted environmental sampling every 6 weeks and concurrently administered detailed questionnaires to collect information on work-related symptoms, psychosocial factors, and perceptions of the office environments. In multivariate analyses, eye irritation was positively correlated with floor dust [odds ratio (OR) = 1.46; 95% confidence intervals (CI), 1.14-1.86] and reported lack of office cleanliness (OR = 1.52; 95% CI, 1.11-2.08). Nonspecific symptoms were positively associated with unidentified chair fungi (OR = 1.87; 95% CI, 1.11-3.15) and several self-reported conditions, including a history of asthma (OR = 3.15; 95% CI, 1.26-7.87), more people in offices (OR = 1.71; 95% CI, 1.16-2.51), lack of office cleanliness (OR = 2.85; 95% CI, 1.72-4.73), and low job satisfaction (OR = 1.72; 95% CI, 1.06-2.81). Upper respiratory symptoms were positively associated with total fungal concentrations recovered from chair dust (OR = 1.35; 95% CI, 1.07-1.70) and the following self-reported conditions: more people in offices (OR = 1.45; 95% CI, 1.01-2.08), lack of office cleanliness (OR = 1.62; 95% CI, 1.15-2.30), and jobs frequently requiring hard work (OR = 1.43; 95% CI, 1.05-1.95). This study emphasizes the importance of maintaining a clean, uncrowded workspace and the importance of chair fungi as a correlate for health effects.
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Using a semi-quantitative mold exposure index, the National Institute for Occupational Safety and Health (NIOSH) investigated 13 college buildings to examine whether building-related respiratory symptoms among employees are associated with environmental exposure to mold and dampness in buildings. We collected data on upper and lower respiratory symptoms and their building-relatedness, and time spent in specific rooms with a self-administered questionnaires. Trained NIOSH industrial hygienists classified rooms for water stains, visible mold, mold odor, and moisture using semi-quantitative scales and then estimated individual exposure indices weighted by the time spent in specific rooms. The semi-quantitative exposure indices significantly predicted building-related respiratory symptoms, including wheeze [odds ratio (OR) = 2.3; 95% confidence interval (CI) = 1.1-4.5], chest tightness (OR = 2.2; 95% CI = 1.1-4.6), shortness of breath (OR = 2.7; 95% CI = 1.2-6.1), nasal (OR = 2.5; 95% CI = 1.3-4.7) and sinus (OR = 2.2; 95% CI = 1.2-4.1) symptoms, with exposure-response relationships. We found that conditions suggestive of indoor mold exposure at work were associated with building-related respiratory symptoms. Our findings suggest that observational semi-quantitative indices of exposure to dampness and mold can support action to prevent building-related respiratory diseases.
Practical implications:
Current air sampling methods have major limitations in assessing exposure to mold and other biological agents that may prevent the demonstration of associations of bioaerosol exposure with health. Our study demonstrates that semi-quantitative dampness/mold exposure indices, based solely on visual and olfactory observation and weighted by time spent in specific rooms, can predict existence of excessive building-related respiratory symptoms and diseases. Relative extent of water stains, visible mold, mold odor, or moisture can be used to prioritize remediation to reduce potential risk of building-related respiratory diseases. From a public health perspective, these observational findings justify action to correct water leaks and repair water damage in order to prevent building-related respiratory diseases. This approach can also be a basis for developing practical building-diagnostic tools for water-incursion.
We conducted a study on building-related respiratory disease and associated social impact in an office building with water incursions in the northeastern United States. An initial questionnaire had 67% participation (888/1,327). Compared with the U.S. adult population, prevalence ratios were 2.2-2.5 for wheezing, lifetime asthma, and current asthma, 3.3 for adult-onset asthma, and 3.4 for symptoms improving away from work (p < 0.05). Two-thirds (66/103) of the adult-onset asthma arose after occupancy, with an incidence rate of 1.9/1,000 person-years before building occupancy and 14.5/1,000 person-years after building occupancy. We conducted a second survey on 140 respiratory cases, 63 subjects with fewer symptoms, and 44 comparison subjects. Health-related quality of life decreased with increasing severity of respiratory symptoms and in those with work-related symptoms. Symptom status was not associated with job satisfaction or how often jobs required hard work. Respiratory health problems accounted for one-third of sick leave, and respiratory cases with work-related symptoms had more respiratory sick days than those without work-related symptoms (9.4 vs. 2.4 days/year; p < 0.01). Abnormal lung function and/or breathing medication use was found in 67% of respiratory cases, in 38% of participants with fewer symptoms, and in 11% of the comparison group (p < 0.01), with similar results in never-smokers. Postoccupancy-onset asthma was associated with less atopy than preoccupancy-onset asthma. Occupancy of the water-damaged building was associated with onset and exacerbation of respiratory conditions, confirmed by objective medical tests. The morbidity and lost work time burdened both employees and employers.
The Passaic Asthma Reduction Effort (PARE) used an asthma symptom and household exposure factor questionnaire to screen 4634 elementary school children over a 4-year period in Passaic, New Jersey. During the first year, an additional 240 preschool children were also screened. Overall, 16% of the school children were reported by their parents to have been diagnosed with asthma. In all, 30% of responding families claimed to have at least one family member diagnosed with asthma and this was five times more likely if the target child had asthma. Exposures consistently associated with childhood asthma diagnosis included environmental tobacco smoke (ETS), presence of dampness/mold, roaches, and furry pets in the home. Diagnosis of asthma was primarily associated with all six symptoms used in the PARE questionnaire, and secondarily with environmental factors. Puerto Rican and black children had the highest asthma prevalence (26% and 33%), while Mexican children had the lowest (7%). Use of medications and school absenteeism among asthmatic children were associated with wheeze and night cough, but not with any specific environmental exposure. Increased school absenteeism by children undiagnosed with asthma was associated with ETS and dampness/mold in the home. Differences in asthma diagnosis and absenteeism in response to environmental factors were found across ethnic subgroups. Getting asthmatic children on medical management protocols and providing families with education about environmental risk reduction should aid in reducing morbidity in this ethnically complex population. Such coordinated efforts offer the promise of reducing school absenteeism.
The objectives of this study were to develop an initial semi-quantitative estimate of costs of indoor air quality problem prevention, mitigation, and remediation activities in US buildings and to provide useful information for a more comprehensive and accurate survey. This is intended to be more of a map of the territory rather than a precise cost estimate.
Building dampness in the floor construction is known to cause chemical degradation of polyvinyl chloride floor coatings, but few epidemiological studies on this topic have been published. Another topic of interest is the different symptoms in different buildings constructed with different building materials and with different architectural designs. The term Sick Building Syndrome (SBS) is sometimes used to describe irritation to the eyes, skin, and upper airways, headache and fatigue in relation to the indoor environment. The aim of our investigation was to study symptoms in relation to building dampness and type of building in geriatric hospitals. Four hospitals for geriatrics were selected to represent buildings with different ages and design, irrespectively of symptom prevalence. All staff (n = 95) were requested to answer a medical questionnaire, 88 (93%) participated. Measurements of room temperature, relative air humidity, air flow rate, illumination, moulds, bacteria, formaldehyde and other volatile compounds, respirable dust, carbon monoxide, carbon dioxide, nitrogen dioxide and ozone were carried out in all buildings. Statistical analyses were performed by bivariate analysis, and multiple logistic regression, adjusting for possible influence of building age, age of the subjects, gender, tobacco smoke, atopy and the perceived psychosocial work environment. Dampness in the upper concrete floor surface (75–84%), ammonia under the floor [3 parts per million (3 ppm)], and 2-ethyl-1-hexanol in the air were detected in two buildings built in 1985 and 1993. Increased occurrence of ocular, nasal and throat symptoms, and dry facial skin were found in the damp buildings. Those in the specially designed building had fewer of these symptoms. In conclusion, the study provides new evidence on possible health effects of dampness-related alkaline degradation of di(2-ethyl-hexyl) phthalate (DEPH) in PVC-building material. Emissions related to degradation of DEPH due to dampness in the floor construction, detected by an increase of 2-ethyl-1-hexanol in the air, seems to increase the occurrence of ocular, nasal, throat and facial skin symptoms. The indoor environment of one specially designed building with a high ceiling and avoidance of fluorescent lighting and interior plastic materials, seemed to have a positive influence on well-being. Our results support the view that building dampness should be avoided, and shows that it is possible to construct a new building where the inhabitants have few symptoms. Copyright © 1999 John Wiley & Sons, Ltd.
A health and housing questionnaire was administered to children, ages 9-11, living in 24 communities in the United States and Canada. Logistic regression analysis examined the relationship between respiratory health symptoms (bronchitic, asthmatic and lower respiratory) and housing factors. The health risks (expressed as relative odds) were controlled for gender, parental asthma, parental chronic obstructive pulmonary disease and parental education, as well as between-city differences. Lower respiratory symptoms had significantly higher odds ratios reported in older homes (1.12), homes with smokers (1.24), air conditioners (1.14), air cleaners (1.37), and humidifiers (1.47). Home dampness (1.48) and the individual mold and water variables were all significantly associated with increased symptoms. Similar results were reported for bronchitic and asthmatic symptoms. While air conditioners and air cleaners were confounded with symptoms, humidifiers remained significant after controlling for childhood atopy.
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Five hundred and twenty-two teachers from 15 public schools, eight 'water-damaged' schools, and seven 'non-damaged' schools with no visible water damage were included in a cross-sectional design. Mold growth was assessed by recording the amount of dust on the floor and in the air in classrooms and the content of a number of mold species in the dust (CFU/g dust). The evaluation of health symptoms included symptoms recorded by questionnaire and spirometry, bronchial challenge, and CO-diffusion capacity. Nasal lavage fluid was analyzed for IL-8 and ECP. Personal and psychosocial factors were included as confounders. In this study population mucus membrane irritation symptoms (MMI) and general symptoms were reported more frequently by women than by men with odds ratios ranging from 1.4 to 2.1. Women's reports of symptoms from mucous membranes and skin and general symptoms were positively associated with mold exposure. Odds ratio for 'difficult to concentrate' after adjustment for confounders was 11.2 (1.4-90.1, 95% CI) at high levels of mold exposure. None of the lung function tests performed in this study were associated with mold exposure, to the 'water damaged' vs. 'non-damaged' classification, or to the symptoms reported. IL-8 and ECP were not associated either.
Practical implications:
Psychosocial and personal reasons dominate in MMI and general symptoms. Headache and difficulties to concentrate associated with indoor mold exposure, mainly for women. No lung function impairment associated with indoor mold exposure.
This study examined the relationship between measures of home dampness and respiratory illness and symptoms in a cohort of 4,625 eight- to 12-yr-old children living in six U.S. cities. Home dampness was characterized from questionnaire reports of mold or mildew inside the home, water damage to the home, and the occurrence of water on the basement floor. Symptoms of respiratory and other illness were collected by questionnaire. Pulmonary function was measured by spirometry. Signs of home dampness were reported in a large proportion of the homes. In five of the six cities, one or more of the dampness indicators were reported in more than 50% of the homes. The association between measures of home dampness and both respiratory symptoms and other non-chest illness was both strong and consistent. Odds ratios for molds varied from 1.27 to 2.12, and for dampness from 1.23 to 2.16 after adjustment for maternal smoking, age, gender, city of residence, and parental education. The relationship between home dampness and pulmonary function was weak, with an estimated mean reduction of 1.0% in FEF25-75 associated with dampness and 1.6% with molds. We conclude that dampness in the home is common in many areas of the United States and that home dampness is a strong predictor of symptoms of respiratory and other illness symptoms among 8- to 12-yr-old children.
To assess the occurrence of respiratory and other symptoms among workers in relation to dampness in day-care centers, a random sample of 30 day-care centers in the city of Espoo, Finland, was selected for the study. The study population consisted of 268 female day-care workers, who filled in a questionnaire. Dampness was found to be common: water damage had taken place in 70% of the centers, and workers perceived mold odor in 17% of them. Adjusted risk of work-related eye and respiratory symptoms was in general higher among the day-care workers exposed to both water damage and mold odor than among the unexposed. The prevalence of eye symptoms was statistically significantly higher. The results provide new evidence of the importance of dampness and mold problems in the work environment as determinants of respiratory and irritative symptoms.
Indoor risk factors for physician-diagnosed asthma and wheezing in the past 12 months without previous asthma diagnosis were assessed in a survey of parents of 5-9-year-old Seattle primary school students. Among the 925 respondents, 106 (11%) reported a physician diagnosis of asthma, 66 (7%) had wheezing without diagnosis, and 753 (82%) were asymptomatic. After adjusting for age, sex, gender, ethnicity, medical history, socioeconomic status (SES) and parental asthma status, an increased risk of physician diagnosis of asthma was associated with household water damage, the presence of one or more household tobacco smokers, and at least occasional environmental tobacco smoke (ETS) exposure. Similarly, an increased risk of wheezing in the past 12 months among children without diagnosed asthma was associated with household water damage, presence of one or more household tobacco smokers, and occasional or more frequent ETS exposure. No increased risk of either condition was associated with gas, wood, or kerosene stove use, household mold, basement water, or wall/window dampness. Similarities in the indoor risk factors patterns between diagnosed asthma and wheezing without diagnosis suggested a similar etiology of these two conditions. The slightly higher association between ETS and asthma may indicate that parents of diagnosed asthmatics were more conscious of ETS, and were more likely to prohibit household smoking by resident smokers. Future research is needed to quantify which aspects of household water damage are related to respiratory illness.
This cost of illness analysis examines national cost and resource utilization by persons with asthma using a single, comprehensive data source, the 1987 National Medical Expenditure Survey. Direct medical expenditures included payments for ambulatory care visits, hospital outpatient services, hospital inpatient stays, emergency department visits, physician and facility payments, and prescribed medicines. Indirect medical costs included costs resulting from missed work or school and days with restricted activity at work. Point estimates and 95% confidence intervals (CI) were calculated and inflated to 1994 dollars. The total estimated cost was 3.6 to 5.1 billion (95% CI, 7.0 billion), and indirect expenditures were valued at 271 to 2,584, in contrast with $140 for the rest of the sample. Findings from this study indicate that future asthma research and intervention efforts directed at hospitalizations and high-cost patients could help to decrease health care resource use and provide cost savings.
We performed a clinical study in 99 children attending schools with moisture problems and compared the findings with those of 34 children from a reference school. The aim of the study was to evaluate the possible association between respiratory or allergic diseases in the pupils and moisture or mould problems in the school buildings.
Asthma was diagnosed in nine (6.7%) children: eight of them came from the moisture-problem schools and all were over 10 y old. In addition, 17 non-asthmatic children had suffered from wheezing and 21 from long-term cough, both symptoms being suggestive of occult asthma. If moisture problems were observed both at home and in the school, the frequency of asthma was 21% and the combined frequency of asthma and wheezing was 43%. The presence of allergic rhinoconjuntivitis or atopic dermatitis had no association with moisture or mould problems. We performed skin-prick tests to 13 moulds in all the 133 children. A positive reaction (> 3 mm) was observed in only six (5%) of them. All six positive children reacted to at least one moisture-indicative mould, Fusarium roseum, Aspergillus fumigatus, Phoma herbarum or Rhodotorula rubra. None of these cases came from the reference school. There was a significant association between positive reactions to moisture-indicative moulds and asthma; four (44%) of the nine children with asthma had such reactions. In addition, all the 6 reactive children had either asthma or wheezing.
We report preliminary evidence for an association between moisture or mould problems in the school building and the presence of manifest and occult asthma in the pupils. Our results show that skin-test positivity to moulds is rare in children. However, reactivity to moisture-indicative moulds seems to be associated with the occurrence of asthma or wheezing.
Poor indoor air quality has been suggested to be related to the increase in the prevalence of asthma that has occurred in the western world, especially among children and young persons. Apart from the home, school is the most important indoor environment for children.
The aims were to study the prevalence of current asthma among secondary pupils and its relationship to the school environment, but also to personal factors and domestic exposures.
Data on asthmatic symptoms, other health aspects, and domestic exposures were gathered using a questionnaire which was sent to 762 pupils in the seventh form (13-14 years old) in 11 randomly chosen schools in the county of Uppsala in Sweden. Pupils answering 'yes' to having had asthma diagnosed by a physician, and having had recent asthma attacks, or who used asthma medication were defined as having current asthma. Data on exposures at school were gathered by measurements in 28 classrooms. The relationship between asthma and exposures was analysed by multiple logistic regression.
The questionnaire was completed by 627 (82%). Current asthma was found among 40 pupils (6.4%). Current asthma was more common in those who had an atopic disposition, or food allergy, or who had attended a day care centre for several years. Controlling for these factors, current asthma was related to several factors in the school environment. There were more pupils with current asthma in schools that were larger, had more open shelves, lower room temperature, higher relative air humidity, higher concentrations of formaldehyde or other volatile organic compounds, viable moulds or bacteria or more cat allergen in the settled dust.
Although the pupils attended school for a minor part of their time, our study indicates that the quality of the school environment is of importance and may affect asthmatic symptoms.
We sought to determine the association between office workers' respiratory tract symptoms and immediate skin test reactions with exposure to fungal and house dust mite aeroallergens at their work sites.
An initial prevalence survey was conducted among 1102 full-time workers in six mechanically ventilated, air-conditioned, nonindustrial buildings in downtown Montreal. Detailed environmental measures of 214 subjects' work sites were determined. Half of the workers reported frequent work-related respiratory tract symptoms on the initial survey. Participants simultaneously underwent allergy skin prick testing and completed a second self-administered questionnaire.
Contaminant levels were low and not associated with symptoms in the great majority of workers. For approximately 17% of workers, symptoms were associated with exposure to total concentrations of house dust mite allergen greater than 1 microg/gm floor dust (odds ratio [OR], 5.0; 95% confidence interval [CI], 1.3, 19.5]) or to detectable airborne Alternaria allergens in their offices (OR, 3.3; 95% CI, 1.2, 9.4 and in the ventilation system supplying their offices (OR, 3.9; 95% CI, 1.6, 9.6). Workers with positive skin test reactions to Alternaria extract were exposed at their work site to airborne Alternaria allergen (OR, 4.4; 95% CI, 1.4, 14.5) and cited significantly more respiratory symptoms on both questionnaires. Detection of airborne Alternaria allergen at work sites was significantly associated with detection in the ventilation system (OR, 4.0; 95% CI, 1.4,10.9); this was in turn associated with lower efficiency filters.
Potentially avoidable exposure to aeroallergens accounted for symptoms in a small subgroup of office workers with frequent work-related respiratory tract symptoms.
Prevalence of and risk factors for asthma were examined in 1085 Head Start families at 18 Head Start sites in four high-risk community areas in 1994. A total of 13.9% of the families reported diagnosed asthma in their Head Start child and 18.8% reported that their child wheezed in the last 12 months. A total of 26.9% of respondents reported asthma in the immediate family of the child. Low birth weight (1500-2499 g), very low birth weight (<1500 g), and self-reported exposure to dampness or mold in the last 12 months were significantly associated with self-reported diagnosed asthma (OR = 1.93; 95% CI 1.17-8.73), (OR = 4.5; 95% CI 1.25-16.3), and (OR = 1.94; 95% CI 1.23-3.04), respectively. The young age of the children in Head Start, as well as the high prevalence of asthma in their families, suggest that the Head Start programs offer an unusual opportunity for asthma prevention programs.
Indoor bioaerosols (i.e., bacteria, fungi, endotoxin, and beta-1,3-glucan) were determined in daycare centers, office buildings, and domestic environments in the Taipei area. In addition, we used a questionnaire survey to determine associations between indoor dampness, bioaerosols, and airway inflammation and systemic symptoms. We demonstrated that the median levels of indoor bacteria and fungi were the highest in daycare centers, followed by those in homes and office buildings. Similar patterns were observed for endotoxin and beta-1,3-glucan. The prevalences of airway inflammation and systemic symptoms were higher for females in office buildings than for employees in daycare centers; all symptoms were more prevalent in females than males. With respect to the relationship between bioaerosol exposure and airway inflammation and systemic symptoms, we found a strong association between beta-1,3-glucan and lethargy/fatigue.
To study the relationships between dampness in concrete floors and building design on the one hand, and symptoms and medical signs of the eyes and nose in hospital workers, on the other.
Four hospitals for geriatrics were selected to represent buildings with different ages and design, irrespective of symptom prevalence. The first building was built in 1925. The second, built in 1985, was known to have dampness in the floor. Conventional building techniques were used in the third building, built in 1993, and the last building was built in 1994, and was specially designed to include high ceilings, and minimal use of fluorescent lighting and interior plastic materials. The interior surfaces were painted with water-based beeswax glazing. All staff (n=95) working day shifts were invited to take part in a medical examination of the eyes and nose including acoustic rhinometry and nasal lavage, and a medical questionnaire, and 93% participated. Measurements of temperature, relative air humidity, air flow, illumination, volatile organic compounds (VOCs), molds, and bacteria were carried out in all buildings, together with measurements of formaldehyde, respirable dust, carbon monoxide (CO), carbon dioxide (CO(2)), nitrogen dioxide (NO(2)) and ozone. Statistical analyses were performed by bivariate analysis, and linear, ordinal, and logistic multiple regressions, adjusting for age, gender, tobacco smoking, atopy, and the perceived psychosocial work environment.
Dampness in the upper concrete floor surface (75-84%), ammonia under the floor [3 parts per million (ppm)], and 2-ethyl-1-hexanol in the air were detected in the two buildings built in 1985 and 1993. Increased occurrences of ocular and nasal symptoms, an increased concentration of lysozyme in nasal lavage, and decreased tear film stability were found in the subjects working in the damp buildings. Those in the specially designed building had fewer ocular and nasal symptoms, and increased tear film stability. All buildings had low levels of formaldehyde, molds, bacteria, ozone, and NO(2). The lowest total concentration of VOCs, and the highest concentration of specific VOCs of microbial origin, were found in the building with special design.
The study provides new evidence of the role of dampness-related alkaline degradation of di-(2-ethylhexyl) phthalate (DEHP) in polyvinyl chloride (PVC) building material. Emissions related to degradation of DEHP due to dampness in the floor, indicated by increased 2-ethyl-1-hexanol in the air, seem to increase both the secretion of lysozyme from the nasal mucosa and the occurrence of ocular and nasal symptoms. The indoor environment of the specially designed building with high ceilings and no fluorescent lighting or interior plastics seemed to have a positive influence on the nasal and ocular mucous membranes.
Initially, we performed a questionnaire study on 622 school children aged 7 to 13 y. The study was supplemented with a clinical study including skin prick tests to 13 molds in 212 (34%) children with doctor-diagnosed asthma or parental-reported wheezing or prolonged cough. These children were attending one of two elementary schools, one with moisture problems (index) school, the other being the control school. The objective of the study was to evaluate whether exposure to moisture and sensitization to molds are associated with respiratory manifestations in school children.
The prevalence of asthma was 4.8%, which was similar in the children from both schools. The children from the index school more often had wheezing (16% vs 6%; p <0.001) and cough (21% vs 9%: p < 0.001) symptoms than control children. Positive skin reactions to molds were rare (2.4%), being present in 7% of asthmatic and in 1-2% of non-asthmatic children (NS). Lower respiratory tract infections were more common in the spring than in the fall in children from the index school, but not in control children, and the difference between the schools was significant in emergency visits (OR =2.0, p <0.01) and antibiotic courses (OR = 2.1, p < 0.01).
We found evidence of an association between moisture or mold problems in the school building and the occurrence of respiratory infections, repeated wheezing and prolonged cough in school children.
Asthma symptoms in adults in relation to the indoor environment.
To study the relationships between current asthma symptoms (wheeze or attacks of breathlessness) and the indoor environment and dampness in hospitals.
A study among personnel (n = 87) in four geriatric hospitals in winter. Indoor air pollutants, dampness in the concrete floor, and allergens in settled dust were measured. Multiple logistic regression analysis was applied, adjusting for age, sex, atopy, and dampness in the participants' own dwellings.
Current asthma symptoms were reported by 17%, and 8% had doctor's diagnosed asthma. Asthma symptoms were more common (adjusted odds ratio = 8.6; 95% confidence interval 1.3-56.7) in two buildings with signs of dampness-related degradation of di(ethylhexyl)-phthalate (DEHP) in polyvinyl chloride (PVC) floor material, detected as presence of 2-ethyl-1-hexanol (2-32 microg/m3) in indoor air (CAS nr 104-76-7). Asthma symptoms were related to higher relative humidity in the upper concrete floor construction, and ammonia in the floor. The newest hospital, built by an anthroposophic society, had low levels of dampness and few asthma symptoms (4%). Cat (Fel d1) and dog allergens (Can f1) were found in dust from all buildings (geometric mean 340 ng/g and 2490 ng/g, respectively). House dust mite allergens (Derp1, Derf1, or Derm1) were found in 75% of all samples (geometric mean 130 ng/g). There was no relationship between allergen levels and asthma symptoms.
Asthma symptoms may be related to increased humidity in concrete floor constructions and emission of 2-ethyl-1-hexanol, an indicator of dampness-related alkaline degradation of plasticiser DEHP. Moreover, geriatric hospitals can be contaminated by significant amounts of cat, dog and mite allergens.
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.
As new health care strategies compete with existing ones for limited resources, the health care system and its providers are beginning to turn to health economic analyses to help inform choices in the delivery of care. This 2-part review examines the current health economic literature for asthma and rhinitis. This first installment of the review focuses on studies that characterize the economic burden of asthma and rhinitis and examines how resources are allocated to the care of persons with asthma and rhinitis. In 1998, asthma in the United States accounted for an estimated 12.7 billion dollars annually. Similarly, in 1994, allergic rhinitis was estimated to cost 1.2 billion dollars. Most of the costs for these conditions are attributed to direct medical expenditures, with medications emerging as the single largest cost component. Indirect costs also represent an important social effect. While cost-of-illness studies help to characterize the economic burden, comparative health economic studies evaluate the value of new and existing strategies for clinical care. The second part of this review will explore how comparative studies have contributed to understanding how to best diagnose and treat asthma and allergic rhinitis.
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.
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.
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.
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.
Upper airway symptoms have frequently been reported in people working or residing in damp buildings. However, little information has been available on objective pathophysiologic findings in relation to these environments. Twenty-eight teachers, who had worked for at least five years in a recently renovated school that had had severe moisture problems for years, were randomly selected for this study. Eighteen teachers, who had worked in another school that had no moisture problems, were randomly selected to serve as the control group. Although remedial measures had been taken, an increase in the prevalence of mucous membrane irritations was still reported by the teachers in the target school. We used a nasal challenge test with three concentrations of histamine (1, 2 and 4 mg/mL). Recordings of swelling of the nasal mucosa were made with rhinostereometry, a very accurate optical non-invasive method. The growth curves of mucosal swelling induced by the three concentrations of histamine differed significantly between the two groups (p < 0.01). The frequencies of atopy, evaluated with the skin-prick test, were almost identical in both groups. The study indicates that long-term exposure to indoor environments with moisture problems may contribute to mucosal hyperreactivity, of the upper airways. Such hyperreactivity also seems to persist for at least one year after remedial measures have been taken.
To study the relationship between basophil histamine release (HRT) to indoor moulds, indicating specific IgE, and building-related symptoms (BRS), asthma, and hay fever in individuals working in damp and mouldy buildings.
A cross-sectional study was performed among 86 school staff members, who on average had worked 143 months (range: 3-396) in moist buildings with mould growth in the constructions. A questionnaire concerning mucous membrane symptoms, facial skin symptoms, central nervous system symptoms, hay fever, and asthma was fulfilled by the participants, and blood samples were taken. Eight mould species growing on building constructions were identified and cultivated to obtain allergenic materials for testing. The presence in serum of IgE specific to moulds was verified by histamine release test (HRT) based on passive sensitization of basophil leukocytes. The validity of the method was confirmed by parallel testing of patients allergic to grass- and birch pollen and by the shift from positive to negative response after removal of serum IgE and by using sham sensitization.
The prevalence of most BRS was between 32% and 62%. Positive HRT, showing serum IgE specific to one or more of the moulds, was observed in 37% of the individuals. The highest frequency of positive HRT was found to Penicillium chrysogenum and then to Aspergillus species, Cladosporium sphaerospermum and Stachybotrys chartarum. A significant association was found between most BRS and positive HRT, whereas no association was observed between positive HRT to moulds and self reported hay fever or asthma.
Positive HRT to indoor moulds, showing the presence in serum of IgE specific to the fungi, was found to be related to BRS in individuals working in damp and mouldy buildings. Whether the association is of causal character is a question for further studies. The test may be useful in the evaluation and study of possible mould induced BRS.
Several epidemiological investigations concerning indoor environments have indicated that "dampness" in buildings is associated to health effects such as respiratory symptoms, asthma and allergy. The aim of the present interdisciplinary review is to evaluate this association as shown in the epidemiological literature. A literature search identified 590 peer-reviewed articles of which 61 have been the foundation for this review. The review shows that "dampness" in buildings appears to increase the risk for health effects in the airways, such as cough, wheeze and asthma. Relative risks are in the range of OR 1.4-2.2. There also seems to be an association between "dampness" and other symptoms such as tiredness, headache and airways infections. It is concluded that the evidence for a causal association between "dampness" and health effects is strong. However, the mechanisms are unknown. Several definitions of dampness have been used in the studies, but all seems to be associated with health problems. Sensitisation to mites may be one but obviously not the only mechanism. Even if the mechanisms are unknown, there is sufficient evidence to take preventive measures against dampness in buildings.
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.
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.
Asthma, a chronic disease occurring among both children and adults, has been the focus of clinical and public health interventions during recent years. In addition, CDC has outlined a strategy to improve the timeliness and geographic specificity of asthma surveillance as part of a comprehensive public health approach to asthma surveillance.
This report presents national data regarding self-reported asthma prevalence, school and work days lost because of asthma, and asthma-associated activity limitations (1980-1996); asthma-associated outpatient visits, asthma-associated hospitalizations, and asthma-associated deaths (1980-1999); asthma-associated emergency department visits (1992-1999); and self-reported asthma episodes or attacks (1997-1999).
CDC's National Center for Health Statistics (NCHS) conducts the National Health Interview Survey annually, which includes questions regarding asthma and asthma-related activity limitations. NCHS collects physician office-visit data in the National Ambulatory Medical Care Survey, emergency department and hospital outpatient data in the National Hospital Ambulatory Medical Care Survey, hospitalization data in the National Hospital Discharge Survey, and death data in the Mortality Component of the National Vital Statistics System.
During 1980-1996, asthma prevalence increased. Annual rates of persons reporting asthma episodes or attacks, measured during 1997-1999, were lower than the previously reported asthma prevalence rates, whereas the rates of lifetime asthma, also measured during 1997-1999, were higher than the previously reported rates. Since 1980, the proportion of children and adults with asthma who report activity limitation has remained stable. Since 1995, the rate of outpatient visits and emergency department visits for asthma increased, whereas the rates of hospitalization and death decreased. Blacks continue to have higher rates of asthma emergency department visits, hospitalizations, and deaths than do whites.
Since the previous report in 1998 (CDC. Surveillance for Asthma--United States, 1960-1995. MMWR 1998;47[No. SS-1]:1-28), changes in asthma-associated morbidity and death have been limited. Asthma remains a critical clinical and public health problem. Although data in this report indicate certain early indications of success in current asthma intervention programs (e.g., limited decreases in asthma hospitalization and death rates), the continued presence of substantial racial disparities in these asthma endpoints highlights the need for continued surveillance and targeted interventions.
We evaluated relationships between lower respiratory symptoms and risk factors for microbiological contamination in office buildings.
The National Institute for Occupational Safety and Health collected data from 80 office buildings during standardized indoor environmental health hazard evaluations. Present analyses included lower respiratory symptom-based outcome definitions and risk factors for potential microbiologic contamination. Multivariate logistic regression models for selected outcomes identified key risk factors.
Adjusted odds ratios (95% confidence intervals) for "at least three of four work-related lower respiratory symptoms" were, for debris in ventilation air intake, 2.0 (1.0-3.9), and for poor drainage in air-conditioning drip pans, 2.6 (1.3-5.2). Adjusted associations with risk factors were consistently stronger for outcomes requiring both multiple symptoms and improvement away from work, and somewhat stronger among diagnosed asthmatics.
Moisture and debris in ventilation systems, possibly by supporting microbiologic growth, may increase adverse respiratory effects, particularly among asthmatics. Data from more representative buildings are needed to confirm these findings.
1 Considering the amount of time spent indoors, housing conditions are of particular interest. More specifically, several studies in the U.S. and elsewhere have found that the prevalence of asthma and other respiratory symptoms among both children and adults are higher in homes with reported dampness or mold. 2-5 Mildew (mold in early stage) and molds are fungi that grow on organic materials almost anywhere indoors and outdoors. 6 They thrive in moist environments - mold growths or colonies can develop on damp surfaces within 24 to 48 hours - and reproduce by making small, lightweight spores that travel through the air. 6 The work presented here examines the relationship between home dampness/mildew odor and asthma in Rhode Island (RI).At the national level, Healthy People 2010 includes the following objective relevant to environmental risk factors: increase the number of "persons with asthma who receive assistance with assessing and reducing exposure to environmental risk factors in their home, school, and work environments." 7
Workers in modern office buildings frequently have unexplained work-related symptoms or combinations of symptoms. We assessed whether ultraviolet germicidal irradiation (UVGI) of drip pans and cooling coils within ventilation systems of office buildings would reduce microbial contamination, and thus occupants' work-related symptoms.
We undertook a double blind, multiple crossover trial of 771 participants. In office buildings in Montreal, Canada, UVGI was alternately off for 12 weeks, then turned on for 4 weeks. We did this three times with UVGI on and three times with it off, for 48 consecutive weeks. Primary outcomes of self-reported work-related symptoms, and secondary outcomes of endotoxin and viable microbial concentrations in air and on surfaces, and other environmental covariates were measured six times.
Operation of UVGI resulted in 99% (95% CI 67-100) reduction of microbial and endotoxin concentrations on irradiated surfaces within the ventilation systems. 771 participants appeared to remain masked, and reported no adverse effects. On the basis of within-person estimates, use of UVGI was associated with significantly fewer work-related symptoms overall (adjusted odds ratio 0.8 [95% CI 0.7-0.99]), as well as respiratory (0.6 [0.4-0.9]) and mucosal (0.7 [0.6-0.9]) symptoms than was non-use. Reduction of work-related mucosal symptoms was greatest among atopic workers (0.6 [0.5-0.8]), and never-smokers (0.7 [0.5-0.9]). With UVGI on, never-smokers also had large reduction of work-related respiratory (0.4 [0.2-0.9]), and musculoskeletal symptoms (0.5 [0.3-0.9]).
Installation of UGVI in most North American offices could resolve work-related symptoms in about 4 million employees, caused by microbial contamination of heating, ventilation, and air-conditioning systems. The cost of UVGI installation could in the long run prove cost-effective compared with the yearly losses from absence because of building-related illness.
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.
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The scientific literature on health effects from dampness in buildings, including mite exposure over the period 1998-2000 has been reviewed by an European group (EUROEXPO) of eight scientists in experience from medicine, epidemiology, toxicology and engineering. Forty studies deemed relevant have been the foundation for the conclusions. Dampness in buildings is a risk factor for health effects among atopics and non-atopics both in domestic and in public environments. However, the literature is not conclusive in respect of causative agents, e.g. mites, microbiological agents and organic chemicals from degraded building materials. There is a strong need for more multidisciplinary studies including expertise from all relevant areas. A general conclusion from the work was that there is a strong need for multidisciplinary reviews in scientific journals of articles dealing with associations between indoor environmental factors and health effects.
Practical implications:
There is good evidence for a true association between dampness in buildings and health. As the causative factors behind this association are not known, the main focus in practical investigations should be on finding out and remediate the reasons for the humidity problem.
To review a series of 55 teachers from schools in Connecticut who presented consecutively to our clinic, and to summarize our clinical experience with work-related disease in this population, which could lead to a more formal study.
Retrospective chart review; data were abstracted concerning clinical and environmental factors and entered into a statistical spreadsheet program (JMP for Windows).
Of the 55 educators, 22 were diagnosed with upper respiratory syndromes (rhinitis or sinusitis), three with bronchitis, and 23 with asthma. Of the 23 with asthma, 20 presented with active or symptomatic asthma, and seven of these were incident cases of occupational asthma. In addition, four cases (7%) of granulomatous lung disease (two hypersensitivity pneumonitis and two sarcoidosis) were diagnosed. Finally, three patients (5%) received only nonrespiratory diagnoses (panic disorder, sicca syndrome, and vertigo). In 33 work-places, the exposures of concern were predominantly related to ongoing "dampness" or visible mold growth. The remaining 22 work-places were "dry." Symptoms varied according to the work-place environment, with more patients from water damaged (vs dry) work-places having upper respiratory symptoms (76% vs 45%) and asthma (45% vs 23%). All seven patients with incident asthma and all four patients with interstitial lung disease worked in schools with documented water incursion.
Work-place exposures in water damaged school buildings are risk factors for development of work-related lower respiratory disease in schoolteachers and staff. Identification of such high-risk environments can be done by a simple but thorough qualitative evaluation during a walk-through inspection, and it should not require air sampling or surface sampling protocols for microbial contaminants.
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In this stratified cross-sectional study in eight 'wet' and seven 'dry' schools, 1024 adolescent school children reported potentially building-related symptoms (BRS) in self-administrated questionnaires. From their classrooms dust samples were collected from floors, ventilation ducts, and air; settled dust was collected in cardboard boxes over a period of 5 months. Measurements of temperature, relative humidity and CO2 were performed. BRS were strongly associated with personal factors like recent airway infections, hay fever, asthma and psycho-social work load, but also to molds in floor dust and presence of mechanical ventilation. The association between molds in floor dust and BRS has in stratified analyses shown a strong association among adolescent school boys, and no association among adolescent school girls using multivariable analyses controlling for relevant confounders. In contrast to the menstruating school girls, the symptoms among the small group of not yet menstruating girls were associated with the levels of molds in floor dust. Their symptom prevalences were very similar to those of the boys. This finding makes us suggest a new hypothesis: The higher endogenous estrogen levels of sexually matured adolescent females seems to protect them from the effects of molds in dust, despite their overall higher symptom prevalence.
Practical implications:
In this cross-sectional epidemiological study of adolescent school children we found independent significant positive associations between building-related symptoms and viable molds in floor dust in boys and non-menstruating girls. In contrast, no such associations were seen among menstruating girls. The identification of these two susceptible groups adds further support the relevance of minimizing sources of dust and mold exposure.
Unlabelled:
We investigated the associations of fungal and endotoxin levels in office dust with respiratory health in 888 (67% participation) occupants of a water-damaged building. We analyzed floor and chair dusts from 338 workstations for culturable fungi and endotoxin. Based on averages, we ranked each floor of the building as low, medium, or high for occupants' exposure to each of these agents. Multivariate logistic regression models for building-related symptoms included this ranking of fungi and endotoxin, age, gender, race, smoking status, and duration of occupancy. Using floor dust measures, we found significantly increased odds for lower respiratory symptoms [wheeze, chest tightness, attacks of shortness of breath, and attacks of cough: odds ratios (OR) = 1.7 (95% confidence interval (CI): 1.02-2.77) to 2.4 (95% CI: 1.29-4.59)], throat irritation [OR = 1.7, (95% CI: 1.06-2.82)], and rash/itchy skin [OR = 3.0, (95% CI: 1.47-6.19)] in the highest fungal exposure group compared to the lowest, with generally linear exposure-response relationships. Nonlinear relationships were observed for many of these symptoms and endotoxin in floor dust. Interaction models showed that endotoxin modified effects of fungi on respiratory symptoms. Our findings of exposure interactions and exposure-response relationships of fungal and endotoxin with increased risk of building-related symptoms contribute to an understanding of the role of microbial agents in building-related asthma and respiratory and systemic symptoms.
Practical implications:
Our demonstration of exposure-response relationships between measurements of fungi and/or endotoxin in floor dusts and building-related symptoms implies that microbial agents in floor dust may be a good surrogate measure for dampness-related bioaerosol exposure, considering that measurements of microbial agents in air often fail to demonstrate the associations between exposure and health. In addition, our finding that endotoxin exposure may change the effect of fungal exposure (and vice versa) on respiratory heath suggests that exposure to both fungi and endotoxin should be assessed in epidemiological investigations examining the effect of fungal or endotoxin exposure on respiratory health in indoor environments.
Unlabelled:
The Institute of Medicine (IOM) of the National Academy of Sciences recently completed a critical review of the scientific literature pertaining to the association of indoor dampness and mold contamination with adverse health effects. In this paper, we report the results of quantitative meta-analyses of the studies reviewed in the IOM report plus other related studies. We developed point estimates and confidence intervals (CIs) of odds ratios (ORs) that summarize the association of several respiratory and asthma-related health outcomes with the presence of dampness and mold in homes. The ORs and CIs from the original studies were transformed to the log scale and random effect models were applied to the log ORs and their variance. Models accounted for the correlation between multiple results within the studies analyzed. Central estimates of ORs for the health outcomes ranged from 1.34 to 1.75. CIs (95%) excluded unity in nine of 10 instances, and in most cases the lower bound of the CI exceeded 1.2. Based on the results of the meta-analyses, building dampness and mold are associated with approximately 30-50% increases in a variety of respiratory and asthma-related health outcomes.
Practical implications:
The results of these meta-analyses reinforce the IOM's recommendation that actions be taken to prevent and reduce building dampness problems, and also allow estimation of the magnitude of adverse public health impacts associated with failure to do so.
National Expenditures for IAQ Problem Prevention or Mitigation
- H Levin
Levin, H. (2005) National Expenditures for IAQ Problem Prevention or Mitigation. LBNL 58694, Berkeley, CA: Lawrence Berkeley National Laboratory Report.
Health related costs of moisture and mold in dwellings
- Ttl Nguyen
- T Pentikainen
- P Rissanen
- M Vahteristo
- T Husman
- A Nevalainen
Nguyen TTL, Pentikainen T, Rissanen P, Vahteristo M, Husman T, Nevalainen A (1998) Health related
costs of moisture and mold in dwellings. National Public Health Institute, Kuopio, Finland.
National Center for Health Statistics. Health E Stats. Asthma prevalence, health care use and mortality
CDC, (2006a) National Center for Health Statistics. Health E Stats. Asthma prevalence, health care use
and mortality, 2002. Centers for Disease Control.
http://www.cdc.gov/nchs/products/pubs/pubd/hestats/asthma/asthma.htm.
Mold: The $1 billion challenge. Skyrocketing claims drive the search for solutions. American Association of Insurance Services perspective. Roughnotes Magazine
- Rj Prahl
Prahl, RJ, (2002) Mold: The $1 billion challenge. Skyrocketing claims drive the search for solutions.
American Association of Insurance Services perspective. Roughnotes Magazine, November, 2002.