Health effects of mold in children

Relationships between Exposure to Bioaerosols, Moldy Surface and Symptoms in French Mold-Damaged Homes

Air quality in homes is a major concern in Europe, where people spend most of their time indoors. According to the World Health Organization, numerous houses are subject to dampness that can lead to mold growth, with associated health and economic consequences. Our goal was to characterize the human exposure to bioaerosols in French mold-damaged houses but also to study the effects of these bioaerosols as suffered by the inhabitants of these houses. A global approach including both field study and laboratory experimentation was used to investigate 48 mold-damaged homes. Among a wide fungal diversity, 101 viable species, Aspergillus versicolor, Penicillium chrysogenum and P. crustosum were observed as recurrent species and could be used as microbial indicators of indoor air quality. Statistical analyses highlighted a relationship between the concentrations of these recurrent molds and the levels of surface contamination by molds in homes. Fever, cough, dyspnea, flu-like symptoms were observed with several fungal strains (A. versicolor, P. chrysogenum and P. crustosum) or in relation to moldy odor. Relationships between particles of 2 to 15 µm diameter and headaches and dizziness were also observed. In our study, we identified a cutaneous effect (itching) in relationship to the airborne concentration of A. versicolor.

Microbial exposure to dairy farmers' dwellings and COPD occurrence

Dairy farming is a risk factor for chronic obstructive pulmonary disease (COPD). The aim was to determine predictive markers either in blood samples or in dwelling dust samples by comparing COPD and healthy controls with or without farming activity. Dust was collected and analyzed by real-time quantitative PCR. ELISA and DELFIA® were performed to assay the level of specific IgG and IgE of 10 targeted microorganisms. The dwelling exposure of farmers was higher than in the non-farmers (Especially Eurotium amstelodami and Lichtheimia corymbifera). The IgG response against Wallemia sebi and Saccharopolyspora rectivirgula was more often higher in the farmers than the non-farmers. However, exposure and sensitization to the microorganisms tested cannot explain the occurrence of COPD in the dairy farmers' population. COPD development is probably caused by multiple factors associated with exposure over a period of several years.

Abridged version of the AWMF guideline for the medical clinical diagnostics of indoor mould exposure: S2K Guideline of the German Society of Hygiene, Environmental Medicine and Preventive Medicine (GHUP) in collaboration with the German Association of Allergists (AeDA), the German Society of Dermatology (DDG), the German Society for Allergology and Clinical Immunology (DGAKI), the German Society for Occupational and Environmental Medicine (DGAUM), the German Society for Hospital Hygiene (DGKH), the German Society for Pneumology and Respiratory Medicine (DGP), the German Mycological Society (DMykG), the Society for Pediatric Allergology and Environmental Medicine (GPA), the German Federal Association of Pediatric Pneumology (BAPP), and the Austrian Society for Medical Mycology (ÖGMM)

This article is an abridged version of the AWMF mould guideline "Medical clinical diagnostics of indoor mould exposure" presented in April 2016 by the German Society of Hygiene, Environmental Medicine and Preventive Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin, GHUP), in collaboration with the above-mentioned scientific medical societies, German and Austrian societies, medical associations and experts. Indoor mould growth is a potential health risk, even if a quantitative and/or causal relationship between the occurrence of individual mould species and health problems has yet to be established. Apart from allergic bronchopulmonary aspergillosis (ABPA) and mould-caused mycoses, only sufficient evidence for an association between moisture/mould damage and the following health effects has been established: allergic respiratory disease, asthma (manifestation, progression and exacerbation), allergic rhinitis, hypersensitivity pneumonitis (extrinsic allergic alveolitis), and increased likelihood of respiratory infections/bronchitis. In this context the sensitizing potential of moulds is obviously low compared to other environmental allergens. Recent studies show a comparatively low sensitizing prevalence of 3-10% in the general population across Europe. Limited or suspected evidence for an association exist with respect to mucous membrane irritation and atopic eczema (manifestation, progression and exacerbation). Inadequate or insufficient evidence for an association exist for chronic obstructive pulmonary disease, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis and cancer. The risk of infection posed by moulds regularly occurring indoors is low for healthy persons; most species are in risk group 1 and a few in risk group 2 (Aspergillus fumigatus, A. flavus) of the German Biological Agents Act (Biostoffverordnung). Only moulds that are potentially able to form toxins can be triggers of toxic reactions. Whether or not toxin formation occurs in individual cases is determined by environmental and growth conditions, above all the substrate. In the case of indoor moisture/mould damage, everyone can be affected by odour effects and/or mood disorders. However, this is not a health hazard. Predisposing factors for odour effects can include genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for mood disorders may include environmental concerns, anxiety, condition, and attribution, as well as various diseases. Risk groups to be protected particularly with regard to an infection risk are persons on immunosuppression according to the classification of the German Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, KRINKO) at the Robert Koch- Institute (RKI) and persons with cystic fibrosis (mucoviscidosis); with regard to an allergic risk, persons with cystic fibrosis (mucoviscidosis) and patients with bronchial asthma should be protected. The rational diagnostics include the medical history, physical examination, and conventional allergy diagnostics including provocation tests if necessary; sometimes cellular test systems are indicated. In the case of mould infections the reader is referred to the AWMF guideline "Diagnosis and Therapy of Invasive Aspergillus Infections". With regard to mycotoxins, there are currently no useful and validated test procedures for clinical diagnostics. From a preventive medicine standpoint it is important that indoor mould infestation in relevant dimension cannot be tolerated for precautionary reasons. With regard to evaluating the extent of damage and selecting a remedial procedure, the reader is referred to the revised version of the mould guideline issued by the German Federal Environment Agency (Umweltbundesamt, UBA).

Medical diagnostics for indoor mold exposure

In April 2016, the German Society of Hygiene, Environmental Medicine and Preventative Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin (GHUP)) together with other scientific medical societies, German and Austrian medical societies, physician unions and experts has provided an AWMF (Association of the Scientific Medical Societies) guideline 'Medical diagnostics for indoor mold exposure'. This guideline shall help physicians to advise and treat patients exposed indoors to mold. Indoor mold growth is a potential health risk, even without a quantitative and/or causal association between the occurrence of individual mold species and health effects. Apart from the allergic bronchopulmonary aspergillosis (ABPA) and the mycoses caused by mold, there is only sufficient evidence for the following associations between moisture/mold damages and different health effects: Allergic respiratory diseases, asthma (manifestation, progression, exacerbation), allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. In comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low. Recent studies show a prevalence of sensitization of 3-10% in the total population of Europe. The evidence for associations to mucous membrane irritation and atopic eczema (manifestation, progression, exacerbation) is classified as limited or suspected. Inadequate or insufficient evidence for an association is given for COPD, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis, and cancer. The risk of infections from indoor molds is low for healthy individuals. Only molds that are capable to form toxins can cause intoxications. The environmental and growth conditions and especially the substrate determine whether toxin formation occurs, but indoor air concentrations are always very low. In the case of indoor moisture/mold damages, everyone can be affected by odor effects and/or impairment of well-being. Predisposing factors for odor effects can be given by genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for impairment of well-being are environmental concerns, anxieties, conditioning and attributions as well as a variety of diseases. Risk groups that must be protected are patients with immunosuppression and with mucoviscidosis (cystic fibrosis) with regard to infections and individuals with mucoviscidosis and asthma with regard to allergies. If an association between mold exposure and health effects is suspected, the medical diagnosis includes medical history, physical examination, conventional allergy diagnosis, and if indicated, provocation tests. For the treatment of mold infections, it is referred to the AWMF guidelines for diagnosis and treatment of invasive Aspergillus infections. Regarding mycotoxins, there are currently no validated test methods that could be used in clinical diagnostics. From the perspective of preventive medicine, it is important that mold damages cannot be tolerated in indoor environments.

Indoor fungi: companions and contaminants

This review discusses the role of fungi and fungal products in indoor environments, especially as agents of human exposure. Fungi are present everywhere, and knowledge for indoor environments is extensive on their occurrence and ecology, concentrations, and determinants. Problems of dampness and mold have dominated the discussion on indoor fungi. However, the role of fungi in human health is still not well understood. In this review, we take a look back to integrate what cultivation-based research has taught us alongside more recent work with cultivation-independent techniques. We attempt to summarize what is known today and to point out where more data is needed for risk assessment associated with indoor fungal exposures. New data have demonstrated qualitative and quantitative richness of fungal material inside and outside buildings. Research on mycotoxins shows that just as microbes are everywhere in our indoor environments, so too are their metabolic products. Assessment of fungal exposures is notoriously challenging due to the numerous factors that contribute to the variation of fungal concentrations in indoor environments. We also may have to acknowledge and incorporate into our understanding the complexity of interactions between multiple biological agents in assessing their effects on human health and well-being.

Identification and levels of airborne fungi in Portuguese primary schools

Several studies found associations between exposure to airborne fungi and allergy, infection, or irritation. This study aimed to characterize airborne fungi populations present in public primary schools in Porto, Portugal, during winter through quantification and identification procedures. Fungal concentration levels and identification were obtained in a total of 73 classrooms. The AirIdeal portable air sampler was used in combination with chloramphenicol malt extract agar. Results showed a wide range of indoor fungi levels, with indoor concentrations higher than outdoors. The most prevalent fungi found indoors were Penicillium sp. (>70%) and Cladosporium sp. As evidence indicates that indoor fungal exposures plays a role in asthma clinical status, these results may contribute to (1) promoting and implementing public health prevention programs and (2) formulating recommendations aimed at providing healthier school environments.

Intra-ethnic disparities in respiratory health problems among Hispanic residents impacted by a flood

OBJECTIVES

The primary objective of this article is to assess the respiratory health impacts of a flood disaster on Hispanic people residing in the United States, with a focus on intra-ethnic disparities related to age, sex, socioeconomic status, mold exposure, family conflict, English-language proficiency, and a lack of US citizenship.

METHODS

Data were collected in 2010 after a flood disaster (2006) in El Paso County (Texas), which has a Hispanic majority population. A mail-out population-based survey was used retrospectively to assess respiratory health impacts for 363 people residing in 176 self-identified Hispanic households impacted by the flood; logistic regression was utilized to assess intra-ethnic health disparities in flood impacts.

RESULTS

About 41% of individuals experienced one or more post-flood respiratory health problem. Lower income (OR = 0.532,p = .002), mold exposure (OR = 2.267, p < .001), increased family conflict (OR = 1.452, p = .025), English-language proficiency (OR = 4.023, p < .001) and a lack of US citizenship (OR = 13.111, p = .013) were significantly associated with higher odds of respiratory health problems in the regression model.

CONCLUSION

Statistical findings provide evidence of intra-ethnic disparities in post-flood respiratory health status. Specifically within this Hispanic sample, individuals with lower household incomes, whose homes were covered by larger surface areas of mold, and whose families were characterized by increased tension experienced higher odds of post-flood respiratory health problems. Interestingly, greater English-language proficiency and lacking US citizenship were also risk factors. Given that this is one of the first studies of intra-Hispanic disparities in health following a US-based disaster, the findings underscore the importance of considering diversity within the US Hispanic population when studying environmental and post-disaster respiratory health.

Exposure assessment of residential mould, fungi and microbial components in relation to children's health: achievements and challenges

Each day we are exposed to a complex mixture of microbial agents and components in indoor environments. A major part of this mixture derives from fungal and bacterial origin. The impact between those microbial agents in the home environment in relation to respiratory health in children is still a major issue in research. There is little known about the causal agents that provoke or arrest the development of allergic respiratory disorders in children. Identification is complicated by the biodiversity and variability of microbial components in indoor air as well as the lack of validated and standardized exposure assessment methods. In this review, we aim to consider all important aspects in terms of research which may encounter an epidemiological study. Apart from the need for standardized exposure assessment methods which consider cost, handling and effort, especially for the participants, we suggest that a combination of different analysis methods such as chemical and molecular methods may have the potential to best describe the microbial milieu in indoor environments at present. Further, the impact of mould and moisture remediation activities on health is still heavily under investigated, especially in larger prospective cohorts of children and should be a topic of future research. Moreover, the exposure to mould and microbial agents might be embedded in a broader spectrum of children's health such as behavior and cognitive development.

Impact of environmental controls on childhood asthma

Exposure to allergens early in life can lead to sensitization and the development of childhood asthma. It is thought that increased exposure with the advent of modern housing is likely contributing to the rise in prevalence of childhood asthma during the past few decades. The progression from allergen exposure to sensitization and asthma development has been noted with respect to dust mites, pets, cockroach, mouse, mold, tobacco smoke, endotoxin, and air pollution, although some have found a protective effect with pet and endotoxin exposure. Recent studies have shown that allergen remediation may be beneficial in reducing asthma morbidity and development, although there is also some evidence to the contrary. Examples of allergen remediation that have been studied include the use of dust mite-impermeable covers, high-efficiency particulate air filtration, integrated pest management, home repairs, ventilation improvement, and pet removal. Several multifaceted, randomized controlled trials have shown that reducing multiple early allergen exposures with environmental controls is associated with a decreased risk of asthma.

Characterization of new Alternaria alternata--specific rat monoclonal antibodies

In this study, three different rat hybridoma cell lines secreting monoclonal antibodies (mAbs) recognizing the spores from Alternaria alternata, a plant pathogenic fungus, contaminant of food products and important cause of both allergic rhinitis and asthma, have been characterized. These three mAbs are all of IgM isotype. Two antibodies, A1 and F10, were cross-reactive antibodies recognizing spores from Alternaria, Cladosporium, Penicillium, Aspergillus and Stachybotrys genera, but not the yeasts Saccharomyces cerevisiae or Candida albicans. Competitive and sandwich assays demonstrated that these two mAbs were directed against the same or very close repetitive(s) epitope(s). A1-based sandwich ELISA efficiently detected this epitope in various mould (but not yeast)-soluble extracts prepared from strains grown in the laboratory. Moreover, this A1-based sandwich ELISA detected its cognate epitope in air and dust samples obtained from dwellings. The third antibody, E5, recognized only the spores of Alternaria and the phylogenetically very close Ulocladium botrytis. This E5 antibody is directed against a repetitive epitope found in Alternaria and Ulocladium laboratory extracts and can be used in a sandwich assay for the quantification of these moulds. Therefore, E5 antibody is a promising tool for the development of Alternaria-Ulocladium-specific immunoassays, while A1 and F10 could be interesting tools for the quantification of the total mould biomass.

Mold and human health: separating the wheat from the chaff

The term "mold" is utilized to define the ubiquitous fungal species commonly found in household dust and observed as visible multicellular filaments. Several well-defined human diseases are known to be caused or exacerbated by mold or by exposure to their byproducts. Among these, a solid connection has been established with infections, allergic bronchopulmonary aspergillosis, allergic fungal rhinosinusitis, hypersensitivity pneumonitis, and asthma. In the past decades, other less-defined and generally false conditions have also been ascribed to mold. We will herein review and critically discuss the available evidence on the influence of mold on human health.

The role of indoor allergens in the development of asthma

PURPOSE OF REVIEW

Asthma prevalence has markedly increased over the past 30 years. Although atopy and exposure to environmental allergens are known to exacerbate asthma, recent literature supports a causal role of indoor allergens in disease development.

RECENT FINDINGS

High-risk birth cohorts continue to point to atopy as the main risk factor for developing asthma. Exposure to perennial allergens has also been linked to the development of asthma, though with less consistency. Intervention at the level of allergen exposure and allergic immune response is promising.

SUMMARY

The current model of atopic asthma, the predominant phenotype, incorporates genetic and environmental factors in the development of disease. Although genetic factors are less malleable, the environmental component lends itself to analysis and modification.For many, the development of asthma starts with allergen exposure leading to atopic sensitization and subsequent disease. Several studies support the progression from exposure to sensitization with the potential of extremely high levels of exposure leading to tolerance. Likewise, the progression from atopy to asthma is well documented,especially in genetically predisposed children. Recent intervention trials confirm these findings and begin to show promise for the prevention of asthma by interrupting the allergen exposure==>allergen sensitization==>atopic asthma pathway.

A systematic review of US state environmental legislation and regulation with regards to the prevention of neurodevelopmental disabilities and asthma

BACKGROUND

While much attention is focused on national policies intended to protect human health from environmental hazards, states can also prevent environmentally mediated disease through legislation and regulation. However, relatively few analyses have examined the extent to which states protect children from chemical factors in the environment.

METHODS

Using Lexis Nexis and other secondary sources, we systematically reviewed environmental regulation and legislation in the fifty states and the District of Columbia as of July 2007 intended to protect children against neurodevelopmental disabilities and asthma.

RESULTS

States rarely address children specifically in environmental regulation and legislation, though many state regulations go far to limit children's exposures to environmental hazards. Northeast and Midwest states have implemented model regulation of mercury emissions, and regulations in five states set exposure limits to volatile organic compound emissions that are more stringent than US Environmental Protection Agency standards.

DISCUSSION

Differences in state environmental regulation and legislation are likely to lead to differences in exposure, and thus to impacts on children's health. The need for further study should not inhibit other states and the federal government from pursuing the model regulation and legislation we identified to prevent diseases of environmental origin in children.

Housing and health: intersection of poverty and environmental exposures

The importance of adequate housing for the maintenance of health and well-being has long been a topic of scientific and public health policy discussion, but the links remain elusive. Here we explore the role of the residential environment in the etiology of illness (specifically asthma) and the persistence of socioeconomic health disparities. Housing conditions, shaped by social forces, affect exposure to physical and chemical "toxicants," thereby translating social adversities into individual illness and population health disparities. We discuss the mediating role of housing in determining health outcomes at multiple levels (social-structural, neighborhood, and individual family). To date, little attention has been paid by most environmental health scientists to the social-structural conditions underlying gross inequities in the distribution of toxic exposures, with even less attention to the processes whereby these social conditions may directly affect susceptibility to the toxic exposures themselves. This chapter goes beyond traditional medical and environmental science models to incorporate a range of social and physical determinants of environmental pollutions, illustrating how these conditions result in health and illness. We focus here on childhood asthma as an example of a serious public health problem that has been associated with low income, minority status, and characteristics of the home environment. We end the chapter with a discussion of the environmental justice movement and the role of housing as a potential agent of change and focus of interventions aimed to reduce the harmful effects of environmental pollutants.