Risk factors for mold in housing: a national survey

Residential overcrowding in relation to children's health, environment and schooling - a qualitative study

AIM

To explore how overcrowding affects children's health, environment and schooling.

METHODS

A qualitative study was conducted with individual interviews among 20 participants with occupational experience from overcrowded Stockholm areas but diverse in professions, locations and employers. The interviews were recorded, transcribed and analysed with Systematic Text Condensation.

RESULTS

Almost all participants expressed that overcrowding has a negative impact on children's health, environment and schooling - based on perceptions of precarious and different living conditions for children in overcrowded areas, for example, substandard homes, vulnerability, stress, exclusion, limited resources, lack of learning opportunities, gender differences, confinement, shame, insecurity, conflicts, risk of criminality, and bodily impact, both physical and psychological.

CONCLUSIONS

Our qualitative evidence suggest that overcrowding has a negative impact on children's health, environment and schooling.

Structural Home Defects Are the Leading Cause of Mold in Buildings: The Housing and Health Service Experience

The study aimed to evaluate the contribution of building problems to mold proliferation in dwellings. We investigated 503 dwellings of patients suffering from respiratory diseases, whose attending physicians had requested a home inspection if the area of mold was equal to at least one square meter. After careful visual evaluation and basic environmental measurements performed by a trained technician, environmental issues were classified into building defects, accidental water damage, and condensation. Data analysis demonstrated that building defects were the pre-eminent cause of mold proliferation. Among the building defects, water infiltration through leaks in roofs or walls was the leading cause. These results highlight the need for health professionals managing patients with respiratory diseases to be able to request a home inspection, and for city health authorities to commission professionals who can focus on building problems and find ways to address them.

Overcrowding and Hazardous Dwelling Condition Characteristics: A Systematic Search and Scoping Review of Relevance for Health

Crowding in dwellings is an important public health issue. We hypothesize that overcrowding may cause indirect health effects by adversely affecting the dwelling itself, for example, by increasing dampness leading to mold. We therefore performed a systematic search and a scoping review on overcrowding leading to dwelling condition characteristics of relevance for health. A literature search was performed using the PubMed and Scopus databases up to 5 March 2021. The search yielded 100 records with relevant information. We found that overcrowding is defined in numerous ways and often address "socially deprived" populations. Six studies report associations of overcrowding with at least one dwelling condition characteristic, namely lead, cadmium, microorganism distribution, dust mite and cockroach allergens in dust, cockroach infestation, peeling paint, and mold. One of the studies reports associations between several characteristics, e.g., association of mold with cleanliness and rodent infestation, and points out the common use of pesticides. Additional characteristics were extracted from the remaining 94 records, without data on statistical associations with overcrowding. Our review suggests that multiple potentially hazardous dwelling condition characteristics often coincide in overcrowded dwellings. The epidemiological attribution of health effects to any characteristic is therefore difficult. Causal relationships are even more difficult to establish, as overcrowding is also associated with a range of social and other circumstances that may affect health. The complexity should be considered by scientists and practitioners dealing with overcrowding in dwellings.

Season, Vegetation Proximity and Building Age Shape the Indoor Fungal Communities’ Composition at City-Scale

Exposure to particular microbiome compositions in the built environment can affect human health and well-being. Identifying the drivers of these indoor microbial assemblages is key to controlling the microbiota of the built environment. In the present study, we used culture and metabarcoding of the fungal Internal Transcribed Spacer ribosomal RNA region to assess whether small-scale variation in the built environment influences the diversity, composition and structure of indoor air fungal communities between a heating and an unheated season. Passive dust collectors were used to collect airborne fungi from 259 dwellings representative of three major building periods and five building environments in one city—Lausanne (Vaud, Switzerland)—over a heating and an unheated period. A homogenous population (one or two people with an average age of 75 years) inhabited the households. Geographic information systems were used to assess detailed site characteristics (altitude, proximity to forest, fields and parks, proximity to the lake, and density of buildings and roads) for each building. Our analysis indicated that season was the factor that explained most of the variation in colonies forming unit (CFU) concentration and indoor mycobiome composition, followed by the period of building construction. Fungal assemblages were more diverse during the heating season than during the unheated season. Buildings with effective insulation had distinct mycobiome compositions from those built before 1975 — regardless of whether they were constructed with pre-1945 technology and materials or 1945 — 1974 ones. The urban landscape—as a whole—was a significant predictor of cultivable Penicillium load—the closer the building was to the lake, the higher the Penicillium load—but not of fungal community composition. Nevertheless, the relative abundance of eleven fungal taxa detected by metabarcoding decreased significantly with the urbanization gradient. When urban landscape descriptors were analyzed separately, the explanatory power of proximity to vegetation in shaping fungal assemblages become significant, indicating that land cover type had an influence on fungal community structure that was obscured by the effects of building age and sampling season. In conclusion, indoor mycobiomes are strongly modulated by season, and their assemblages are shaped by the effectiveness of building insulation, but are weakly influenced by the urban landscape.

Thermal Performance of School Buildings: Impacts beyond Thermal Comfort

Based on field study data regarding the winter indoor thermal environment of three classrooms with different building envelopes, this study compared and evaluated these environments, not only related to students' thermal comfort but also to their health. The inadequacy of the conventional New Zealand school building for maintaining a comfortable and healthy winter indoor thermal environment has been identified. A classroom with thermal mass had 31%, 34% and 9% more time than a classroom without thermal mass when indoor temperatures met 16 °C 18 °C and 20 °C respectively and has 21.4% more time than the classroom without thermal mass when indoor relative humidity was in the optimal range of 40% to 60%, in a temperate climate with a mild and humid winter. Adding thermal mass to school building envelopes should be considered as a strategy to improve the winter indoor thermal environment in future school design and development. Adding thermal mass to a school building with sufficient insulation can not only increase winter indoor mean air temperature but can also reduce the fluctuation of indoor air temperatures. This can significantly reduce the incidence of very low indoor temperature and very high indoor relative humidity, and significantly improve the indoor thermal environment.

House characteristics and condition as determinants of visible mold and musty odor: Results from three New Zealand House Condition Surveys in 2005, 2010, and 2015

This study assessed associations between house characteristics and mold and musty odor, using data from three consecutive (2005, 2010, and 2015) New Zealand House Condition Surveys, involving a total of 1616 timber-framed houses. Mold, musty odor, and house characteristics were assessed by independent building inspectors. We used multivariate logistic regression analyses mutually adjusted for other house characteristics for each survey separately. Positive and independent associations were found with tenure, ventilation, insulation, and envelope condition for both mold in living and bedrooms and musty odor. In particular, we found significant dose-response associations with envelope condition, ventilation, and insulation. Odds of mold increased 2.4-15.9 times (across surveys) in houses with the worst building envelope condition (BEC; p < 0.05-0.001 for trend); optimal ventilation reduced the risk of mold by 60% and the risk of musty odor by 70%-90% (p < 0.01 for trend). Other factors associated with mold and musty odor included: tenure, with an approximate doubling of odds of mold across surveys; and insulation with consistent dose-response patterns in all outcomes and surveys tested (p < 0.05 for trend in two surveys with mold and one survey for odor). In conclusion, this study showed the importance of BEC, ventilation, and insulation to avoiding harmful damp-related exposures.

Situating household management of children's asthma in the context of social, economic, and environmental injustice

BACKGROUND

Structural determinants of health are social, economic, and environmental forces that generate unequal opportunities for resources and unequally distribute exposure to risk. For example, economic constraint, racial discrimination and segregation, and environmental injustice shape population-level asthma prevalence and severity. Structural determinants are especially relevant to consider in clinical settings because they affect everyday household asthma management.

OBJECTIVE

To examine how structural determinants shape everyday household management of pediatric asthma and offer a framework for providers to understand asthma management in social context.

DESIGN

Qualitative interviews of caregivers for children with asthma.

PARTICIPANTS

Participants included 41 caregivers in two U.S. cities: St. Louis, Missouri (n = 25) and Gainesville, Florida (n = 16). Most caregivers were women (83%), Black (73%) and/or had low socioeconomic status (SES; 78%). Caregivers cared for children with asthma aged 0-4 (32%), 5-11 (68%) and 12-17 (54%).

APPROACH

We carried out narrative interviews with caregivers using an adapted McGill Illness Narrative Interview and using qualitative analysis techniques (e.g. inductive and deductive coding, constant comparison).

KEY RESULTS

Caregivers highlighted three ways that structural determinants complicated asthma management at home: 1) housing situations, 2) competing household illnesses and issues, and 3) multi-household care.

CONCLUSIONS

By connecting social, economic, and environmental injustices to the everyday circumstances of asthma management, our study can help providers understand how social contexts challenge asthma management and can open conversations about barriers to adherence and strategies for supporting asthma management at home. We offer recommendations for medical system reform, clinical interactions, and policy advocacy.

Microclimate Conditions in Rooms: Their Impact on Mold Development in Buildings

The publication concerns the problem of adopting proper environmental conditions in the assessment of mold development in the so-called thermal bridges in the form of corners. The paper discusses the factors determining the development of mold and the models that predict its growth. The conditions of the internal microclimate, which is used in hygrothermal diagnostics of walls, were also recalled. Thermal bridges are areas where mold development takes place, therefore the climatic conditions in the room taken for their assessment—As it is currently applied—Are considered inappropriate. This thesis is confirmed by the results of in situ studies of changes in temperature and relative humidity in the area of corners. Some of these findings are presented in the work. On their basis, the author introduces the concept of the so-called geometric climate that would take into account the change of these parameters within thermal bridges of the corner type.

Fungal Contaminants in Energy Efficient Dwellings: Impact of Ventilation Type and Level of Urbanization

The presence of growing fungi in the indoor environment has been associated with the development of respiratory problems such as asthma or allergic rhinitis, as well as the worsening of respiratory pathologies. Their proliferation indoors could be a result of water leakage or inadequate ventilation. Although the factors promoting mould growth have been widely investigated in traditional dwellings, little work has been done in energy efficient dwellings. Here, the effectiveness of ventilation type, i.e., natural or mechanical, in influencing mould development was estimated in 44 recent and 105 retrofitted energy efficient dwellings. Fungi growing on surfaces were investigated in the dwellings situated in rural, peri-urban, and urban regions of Switzerland. The presence of these fungi was also investigated in bedroom settled dust. Information on building characteristics and owners' lifestyle were collected. Significant associations were found with the level of urbanisation, the location of mouldy area in dwellings, and the diversity of fungal taxa. Dwellings in peri-urban zones showed the most frequent fungal contamination in the owners' bedroom and the highest diversity of fungal genera among dwellings. While the urbanisation level or the ventilation type favoured no specific genus, we found marked disparities in the diversity of fungi growing on surfaces in naturally ventilated versus mechanically ventilated dwellings. Aspergillus, in particular, was a frequent surface contaminant in bedrooms with natural ventilation, but not in those mechanically ventilated. We observed a strong association between fungal growth on surfaces and the number of fungal particles counted in the settled dust of owners' bedrooms. These results demonstrate the importance of ventilation systems in energy efficient dwellings in controlling fungal proliferation in living areas.

Interactions of superabsorbent polymers based on acrylamide substances with microorganisms occurring in human dwellings

Superabsorbent polymers (SAPs) are most often used in hygienic goods or in the agricultural sector but the range of their application is much broader, including the utilization in advanced building materials. Although SAPs were studied widely during the last decades, the data related to the interactions between the natural environment and various organisms occurring on their surface are still lacking. In addition, SAPs can create a variable gel-forming matter in the presence of water but standard ecotoxicological bioassays are mostly not suitable for testing such type of materials. In this study, the SAPs potential for reducing/supporting unwanted indoor microorganism settlement was analyzed by biological methods under controlled laboratory conditions. Three commonly used SAPs (Cabloc CT, Creasorb SIS, Hydropam) were exposed to selected organisms representing green algae (Hematococcus pluvialis), cyanobacteria (Nostoc sp.), yeasts (Saccharomyces cerevisiae), wood-destroying fungi (Gleophyllium trabeum), and aerial molds. The obtained results indicated that Hydropam provided favorable conditions for Hematococcus pluvialis, Nostoc sp., and Saccharomyces cerevisiae. All three tested SAPs inhibited, both with and without nutrient addition, the growth of Gleophyllium trabeum and aerial molds.

Exposure to Indoor Mouldy Odour Increases the Risk of Asthma in Older Adults Living in Social Housing

Background: Indoor dampness is thought to affect around 16% of European homes. It is generally accepted that increased exposure to indoor dampness and mould contamination (e.g., spores and hyphae) increases the risk of developing and/or exacerbating asthma. Around 30% of people in the Western world have an allergic disease (e.g., allergy, wheeze and asthma). The role of indoor mould contamination in the risk of allergic diseases in older adults is yet to be fully explored. This is of interest because older people spend more time indoors, as well as facing health issues due to the ageing process, and may be at greater risk of developing and/or exacerbating asthma as a result of indoor dampness. Methods: Face-to-face questionnaires were carried out with 302 participants residing in social housing properties located in South West England. Self-reported demographic, mould contamination (i.e., presence of mould growth and mouldy odour) and health information was linked with the asset management records (e.g., building type, age and levels of maintenance). Multivariate logistic regression was used to calculate the odd ratios and confidence intervals of developing and/or exacerbating asthma, wheeze and allergy with exposure to reported indoor mould contamination. We adjusted for a range of factors that may affect asthma outcomes, which include age, sex, current smoking, presence of pets, education, and building type and age. To assess the role of mould contamination in older adults, we compared younger adults to those aged over 50 years. Results: Doctor-diagnosed adult asthma was reported by 26% of respondents, 34% had current wheeze while 18% had allergies. Asthma was common among subjects exposed to reported visible mould (32%) and reported mouldy odour (42%). Exposure to visible mould growth and mouldy odour were risk factors for asthma, but not for wheeze or allergy. Exposure to mouldy odour increased the risk of asthma in adults over the age of 50 years (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.10–5.34) and the risk was higher for females than for males (OR 3.5, 95% CI 1.37–9.08). These associations were modified by a range of built environment characteristics. Conclusions: We found that older adults living in social (public) housing properties, specifically women, may be at higher risk of asthma when exposed to mouldy odour, which has a number of implications for policy makers and practitioners working in the health and housing sector. Additional measures should be put in place to protect older people living in social housing against indoor damp and mould contamination.

Indoor visible mold and mold odor are associated with new-onset childhood wheeze in a dose-dependent manner

Evidence is accumulating that indoor dampness and mold are associated with the development of asthma. The underlying mechanisms remain unknown. New Zealand has high rates of both asthma and indoor mold and is ideally placed to investigate this. We conducted an incident case-control study involving 150 children with new-onset wheeze, aged between 1 and 7 years, each matched to two control children with no history of wheezing. Each participant's home was assessed for moisture damage, condensation, and mold growth by researchers, an independent building assessor and parents. Repeated measures of temperature and humidity were made, and electrostatic dust cloths were used to collect airborne microbes. Cloths were analyzed using qPCR. Children were skin prick tested for aeroallergens to establish atopy. Strong positive associations were found between observations of visible mold and new-onset wheezing in children (adjusted odds ratios ranged between 1.30 and 3.56; P ≤ .05). Visible mold and mold odor were consistently associated with new-onset wheezing in a dose-dependent manner. Measurements of qPCR microbial levels, temperature, and humidity were not associated with new-onset wheezing. The association between mold and new-onset wheeze was not modified by atopic status, suggesting a non-allergic association.

Indoors and health: results of a systematic literature review assessing the potential health effects of living in basements

A new law approved in March 2017 in the Lombardy Region makes it possible to live in basements. Basements are defined as buildings partly below curb level but with at least one-half of its height above the curb. Basements' features and structural characteristics might pose risks to human health. In this paper we adopt a multidisciplinary approach to assess the potential health effects of living in basements. In particular, we define a conceptual framework to describe basements' structural characteristics which are risk factors, as well as the mechanisms through which they impact on human health. We also conduct a systematic review on the scientific databases PubMed,Embase, DOAJ, Proquest and EBSCO to retrieve, pool and critically analyze all available research that quantified the risk of living in basements for different health outcomes. Available evidence suggests living in basements increases the risk of respiratory diseases (asthma and allergic disorders); more heterogeneous data are available for cancers and cardiovascular diseases. As more quantitative data need to be prospectively retrieved to assess and monitor the risk of living in basements for human health, clear minimum requirements for light, air, sanitation and egress are to be defined by technical experts and enforced by policy makers.

Observation-based metrics for residential dampness and mold with dose-response relationships to health: A review

An important proportion of respiratory illness is considered attributable to residential dampness or mold (D/M). Developing health-protective D/M guidelines has been challenging, in part because unhealthy levels of indoor D/M cannot be defined using available microbiological measurements. This review paper explores reported multilevel, observation-based (eg visual or olfactory) D/M metrics for potential in defining unhealthy levels of residential D/M. For many of the 33 multilevel residential D/M metrics identified, health risks generally increased as observed D/M increased. Although some metrics seemed too complex for practical use, simple metrics had among the strongest associations with health outcomes. Available findings suggest the feasibility of setting observation-based D/M thresholds to trigger remedial action, using further improved D/M metrics without microbiological measurements (at least until the actual dampness-related agents that cause illness are better quantified). Additional data would allow setting health-protective D/M thresholds more precisely. Also, metrics could better reflect hidden D/M by more strongly emphasizing mold odor, which has demonstrated strong associations with health effects.

RESILIENCY OF PREFABRICATED DAYCARES AND SCHOOLS: FINNISH PERSPECTIVE TO RELOCATABLE EDUCATION FACILITIES

The industrialised production of prefabricated daycare and school properties offer flexible alternatives for communities for provision of communal services. The paper investigates architectural qualities and financial solutions for rentable and relocatable education facilities in finland. in particular, the focus is on the communal interests in solving the property management with a portfolio of rentable facilities for different time spans ranging from very short term to periods up to over twenty years. The short term rental terms offer solutions for disaster mitigation such as flooding but also spaces during refurbishment of existing buildings, e.g. due to moisture and mould damage. A core issue is a potential sustainable and flexible co-existence of both permanent and flexible modules that can adapt, for example to demographic changes, improving the efficiency of communal property manage­ment. Thus the prefabricated solutions have a potential, if the architectural quality is high enough, to provide alternatives for the real estate strategies of cities also in longer term provision of daycare and school facilities.

Identifying risk factors for exposure to culturable allergenic moulds in energy efficient homes by using highly specific monoclonal antibodies

The aim of this study was to determine the accuracy of monoclonal antibodies (mAbs) in identifying culturable allergenic fungi present in visible mould growth in energy efficient homes, and to identify risk factors for exposure to these known allergenic fungi. Swabs were taken from fungal contaminated surfaces and culturable yeasts and moulds isolated by using mycological culture. Soluble antigens from cultures were tested by ELISA using mAbs specific to the culturable allergenic fungi Aspergillus and Penicillium spp., Ulocladium, Alternaria, and Epicoccum spp., Cladosporium spp., Fusarium spp., and Trichoderma spp. Diagnostic accuracies of the ELISA tests were determined by sequencing of the internally transcribed spacer 1 (ITS1)-5.8S-ITS2-encoding regions of recovered fungi following ELISA. There was 100% concordance between the two methods, with ELISAs providing genus-level identity and ITS sequencing providing species-level identities (210 out of 210 tested). Species of Aspergillus/Penicillium, Cladosporium, Ulocladium/Alternaria/Epicoccum, Fusarium and Trichoderma were detected in 82% of the samples. The presence of condensation was associated with an increased risk of surfaces being contaminated by Aspergillus/Penicillium spp. and Cladosporium spp., whereas moisture within the building fabric (water ingress/rising damp) was only associated with increased risk of Aspergillus/Penicillium spp. Property type and energy efficiency levels were found to moderate the risk of indoor surfaces becoming contaminated with Aspergillus/Penicillium and Cladosporium which in turn was modified by the presence of condensation, water ingress and rising damp, consistent with previous literature.

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.

Modifiable factors governing indoor fungal diversity and risk of asthma

Exposure to dampness and fungi in the home is a known risk factor for individuals with allergic asthma. Inadequate heating and ventilation may lead to dampness and concomitant increased exposure to spores of allergenic fungi such as Aspergillus and Penicillium. These fungi have been cultured from sputum of asthmatic and non-asthmatic individuals, and implicated in the initiation or exacerbation of asthma. Indoor environmental factors influence the presence and concentrations of fungal propagules and, in turn, risk of asthma outcomes. This review aims to identify modifiable risk factors in the built environment that have been shown to influence fungal composition indoors, and to examine this association with the risk of asthma development and/or exacerbation. A complex interaction between residential characteristics, the built environment and the behaviour of people regulate the diversity and concentrations of indoor fungi. Modifiable factors include build age, architectural design, level of maintenance, variations in construction materials, presence of pets, heating and ventilation patterns. Risk of fungal contamination and asthma outcomes are also influenced by low occupant awareness concerning potential health effects and socio-economic factors. Addressing these factors provides an opportunity to improve future housing interventions, though it is not clear how the built environment and occupant behaviours interact to modify the diversity of indoor fungi and resultant risk of asthma. A combination of housing improvements combined with awareness programmes and the alleviation of fuel poverty can be used to lower the allergen burden associated with damp homes. Further research is needed to identify factors that regulate the concentration and diversity of indoor fungi and how this may act as a modifier for asthma outcomes.

Assessing framing assumptions in quantitative health impact assessments: a housing intervention example

Health impact assessment (HIA) is often used to determine ex ante the health impact of an environmental policy or an environmental intervention. Underpinning any HIA is the framing assumption, which defines the causal pathways mapping environmental exposures to health outcomes. The sensitivity of the HIA to the framing assumptions is often ignored. A novel method based on fuzzy cognitive map (FCM) is developed to quantify the framing assumptions in the assessment stage of a HIA, and is then applied to a housing intervention (tightening insulation) as a case-study. Framing assumptions of the case-study were identified through a literature search of Ovid Medline (1948-2011). The FCM approach was used to identify the key variables that have the most influence in a HIA. Changes in air-tightness, ventilation, indoor air quality and mould/humidity have been identified as having the most influence on health. The FCM approach is widely applicable and can be used to inform the formulation of the framing assumptions in any quantitative HIA of environmental interventions. We argue that it is necessary to explore and quantify framing assumptions prior to conducting a detailed quantitative HIA during the assessment stage.

A measure for quantifying the impact of housing quality on respiratory health: a cross-sectional study

BACKGROUND

Damp and mould in homes have been established as risk factors for respiratory health. There is a need for a relatively straightforward assessment of the home that quantifies this risk.

METHODS

Using data from 891 New Zealand houses, the utility of a Respiratory Hazard Index quantifying key attributes related to damp and mould was tested by studying its associations with self-reported respiratory symptoms.

RESULTS

A dose-response relationship was found whereby each unit increase in the Respiratory Hazard Index was associated with an 11% increase in the odds of at least one episode of wheezing/whistling in the chest over the last 12 months (relative odds of 1.11 with a 95% CI 1.04%-1.20%). An 11% increase in the odds of an asthma attack over the last 12 months was estimated (relative odds of 1.11 with a 95% CI 1.01%-1.22%). These estimates were adjusted for household crowding levels, age, sex and smoking status. There was suggestive evidence of more steeply increasing odds of respiratory symptoms with increasing levels of the Respiratory Hazard Index for children aged under 7. In the worst performing houses according to the Index, a 33% reduction in the number of people experiencing respiratory symptoms (relative risk 0.67 with 95% CI 0.53 to 0.85) could be expected if people were housed in the best performing houses.

CONCLUSIONS

This study showed that increased evidence of housing conditions supporting dampness and mould was associated with increased odds of respiratory symptoms. A valid housing assessment tool can provide a rational basis for investment in improved housing quality to improve respiratory health.

Airborne fungal volatile organic compounds in rural and urban dwellings: detection of mould contamination in 94 homes determined by visual inspection and airborne fungal volatile organic compounds method

Moulds can both degrade the materials and structures they colonise and contribute to the appearance of symptoms and diseases in the inhabitants of contaminated dwellings. Only few data have compared the levels of contamination in urban and rural environments and the results are not consistent. The aim of this study was to use a fungal contamination index, based on the detection of specific Microbial Volatile Organic Compounds (MVOC), to determine the exposure to moulds of individuals living in urban and rural dwellings. For this purpose, 94 dwellings (47 in an urban setting in Clermont-Ferrand and 47 in rural areas of the Auvergne region, France) were studied. By demonstrating marked disparities between the proportion of visible contamination (19%) and that of active, visible and/or hidden contamination (59%) and the fact that almost all visible contamination was identified by MVOC, we were able to show that use of the index seemed relevant to confirm the actual presence of fungal contamination in a dwelling. Furthermore, it was possible to demonstrate a relationship between moulds and the presence of water on surfaces (condensation, infiltrations, water damage, etc.). A higher proportion of positive fungal contamination index in rural homes was observed compared to the proportion in urban ones (68% versus 49%; p<0.05).

Respiratory infections in Tamariki (children) and Taitamariki (young people) Māori, New Zealand

The Māori population is young, with 53% aged less than 25 years and with a higher prevalence of both acute (bronchiolitis, pneumonia, pertussis, tuberculosis) and chronic (bronchiectasis) respiratory tract infections than non-Māori. Environmental, economic and poorer access to health promotion programmes and health care rather than specific or genetic underlying disorders appear to contribute to this burden. While new initiatives are needed, we can do better with current public health programmes and building on regional initiatives that have already proven successful.

[Moulds in dwellings: health risks and involved species]

INTRODUCTION

In industrialized countries the population spends 90% of its time in enclosed spaces. Since 1973, energy consumption for heating decreased on average by 36% per dwelling. Low-quality insulation, a fall in temperature and inadequate ventilation translated into high humidity in dwellings, which led to proliferation of moulds.

BACKGROUND

The allergenic, toxic and infectious effects of moulds on human health are documented. However, the potential dose/effect relationship between measured concentrations of indoor moulds and respiratory disorders often remains difficult to assess accurately. In several cases, fungi were demonstrated only as a promoter of health disorders. In a few cases (hypersensitivity pneumonitis, invasive fungal infections), the pathogenesis is without doubt due to environmental fungal exposure in a limited number of patients. On the other hand, the role of fungi was suspected but not proven for some well-defined pathologies, and some ill-defined health disorders, affecting large numbers of patients, such as the Sick Building Syndrome, rhinitis, sinusitis and conjunctivitis, as well as asthma and exacerbations of bronchitis. Eighteen fungal species, suspected of playing a role in public health, have been listed by the French Superior Council of Public Health. For each species, the proliferation conditions, type of substrates contaminated and heath effects reported in the literature are described.

VIEWPOINT

The lack of standardization of measurements of concentrations of fungal species, the interactions with chemical compounds (formaldehydes), organic compounds (mycotoxins, endotoxins) and between species, makes the analysis of indoor fungal contamination complicated. The time has come to establish clearly a relationship between exposure to fungi and health disorders, rather than continuing to investigate factors related to the level of indoor fungal contamination.

Building characteristics associated with moisture related problems in 8,918 Swedish dwellings

Moisture problems in buildings have in a number of studies been shown to increase the risk for respiratory symptoms. The study Dampness in Buildings and Health (DBH) was initiated with the aim to identify health relevant exposures related to dampness in buildings. A questionnaire study about home environment with a focus on dampness problems and health was conducted in one county of Sweden (8,918 homes, response rate 79%). Building characteristics that were associated with one or more of the dampness indicators were for single-family houses, older houses, flat-roofed houses built in the 1960s and 1970s, houses with a concrete slab on the ground that were built before 1983. Moreover, tenancy and earlier renovation due to mould or moisture problems was strongly associated with dampness. A perception of dry air was associated with window-pane condensation, e.g. humid indoor air.

Involving students in real-world research: a pilot study for teaching public health and research skills

BACKGROUND

There is some evidence that medical students consider population health issues less important than other domains in the health sciences and attitudes to this field may become more negative as training progresses. A need to improve research skills among medical students has also been suggested. Therefore we piloted an integrative teaching exercise that combined teaching of research skills and public health, with real-world research.

METHODS

Third year medical students at the University of Otago (Dunedin, New Zealand) filled in a questionnaire on their housing conditions and health. The students were given the results of the survey to discuss in a subsequent class. Student response to this teaching exercise was assessed using a Course Evaluation Questionnaire.

RESULTS

Of the 210 students in the class, 136 completed the Course Evaluation Questionnaire (65%). A majority of those who responded (77%) greatly supported or supported the use of the survey and seminar discussion for future third year classes. Most (70%) thought that the session had made them more aware and concerned about societal problems, and 72% felt that they now had an improved understanding of the environmental determinants of health. Students liked the relevance and interaction of the session, but thought it could be improved by the inclusion of small group discussion. The findings of the students' housing and health were considered by the tutors to be of sufficient value to submit to a scientific journal and are now contributing to community action to improve student housing in the city.

CONCLUSION

In this pilot study it was feasible to integrate medical student teaching with real-world research. A large majority of the students responded favourably to the teaching exercise and this was generally successful in raising the profile of public health and research. This approach to integrated teaching/research should be considered further in health sciences training and continue to be evaluated and refined.

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

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

PRACTICAL IMPLICATIONS

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

Sources of nitrogen dioxide (NO2) in New Zealand homes: findings from a community randomized controlled trial of heater substitutions

Houses in New Zealand have inadequate space heating and a third of households use unflued gas heaters. As part of a large community intervention trial to improve space heating, we replaced ineffective heaters with more effective, non-polluting heaters. This paper assesses the contribution of heating and household factors to indoor NO2 in almost 350 homes and reports on the reduction in NO2 levels due to heater replacement. Homes using unflued gas heaters had more than three times the level of NO2 in living rooms [geometric mean ratio (GMR) = 3.35, 95% CI: 2.83-3.96, P < 0.001] than homes without unflued gas heaters, whereas homes using gas stove-tops had significantly elevated living room NO2 levels (GMR = 1.42, 95% CI: 1.05-1.93, P = 0.02). Homes with heat pumps, flued gas heating, or enclosed wood burners had significantly lower levels of NO2 in living areas and bedrooms. In homes that used unflued gas heaters as their main form of heating at baseline, the intervention was associated with a two-third (67%) reduction in NO2 levels in living rooms, when compared with homes that continued to use unflued gas heaters. Reducing the use of unflued gas heating would substantially lower NO2 exposure in New Zealand homes.

PRACTICAL IMPLICATIONS

Understanding the factors influencing indoor NO2 levels is critical for the assessment and control of indoor air pollution. This study found that homes that used unflued gas combustion appliances for heating and cooking had higher NO2 levels compared with homes where other fuels were used. These findings require institutional incentives to increase the use of more effective, less polluting fuels, particularly in the home environment.

Relation of dampness to sick building syndrome in Japanese public apartment houses

OBJECTIVES

The effect of dampness on sick building syndrome (SBS) symptoms has not been fully investigated in Japan. The purpose of this study is to elucidate the possible effects of dampness on SBS symptoms among residents in Japanese public apartment houses.

METHODS

A questionnaire was used to investigate the degree of dampness in public apartment houses in Asahikawa, Japan, and its effect on SBS symptoms, involving 480 residents in 64 buildings. Dampness indicators were as follows: condensation on the windowpanes, condensation on the walls and/or closets, visible mold in the bathrooms, visible mold on the walls, window frames, and/or closet, moldy odor, slow drying of the wet towels in bathrooms, water leakage, and bad drainage in bathrooms.

RESULTS

All dampness indicators except for visible mold in bathrooms had significantly higher odds ratios (ORs) for all or any SBS symptoms after adjustment. The dampness index, the number of positive dampness indicators, was significantly related to all SBS symptoms after adjustment.

CONCLUSIONS

There are serious problems relating to dampness in Japanese public housing, which affects the health of residents. There is a need to educate the residents about the relationship between dampness and SBS, and building problems should be rectified.

Risques liés à l'habitat: les interventions possibles et leur efficacité

Numerous health risks have been identified in dwellings and are a public health priority. Homes most often accumulate several different risks. Intervention programs must take this reality into account. Identification of a source of chemical pollution in the home makes it possible to correct indoor air quality quickly and inexpensively and provides immediate health benefits. Extermination of mites requires implementation of a group of complementary techniques in all contaminated areas, with help, when possible, from an indoor environment counselor. A team of multidisciplinary indoor habitat and health advisors must assess the health risks of the home. This inexpensive strategy reduces risks, although its effectiveness still requires confirmation. When the building has structural defects or abnormalities, more complex methods of renovation, or even moving, are necessary. There again, a complete assessment of their benefits to occupants' health is necessary.

The design of housing and shelter programs: the social and environmental determinants of inequalities

Both developed and less developed countries are becoming increasingly urbanized. The earlier industrialized countries have developed more infrastructure to support the building of healthy housing, in neighborhoods that are strongly linked to municipal and global health initiatives, but to some degree housing and neighborhood issues vary only in degree between the developing and developed worlds. Overall, a billion people, a third of people living in urban areas, live in slums, where environmental determinants lead to disease. Although communicable diseases predominate in the developing world and have reemerged in the developed world, noncommunicable diseases are also growing disproportionately in the developing world. At a global level, the Millennium Development Goals explicitly focus on an integrated approach to slum upgrading. The per capita cost of slum upgrading is almost twice the cost of providing new affordable housing at the outset. It is argued that to improve health and well-being in the slums we need to have interventions that reduce urban poverty in the broadest sense and improve the deficiencies associated with slums. There is an urgent need to scale up the best-practice interventions. Examples are given of successful local community initiatives that have been set up under national strategies in Tanzania and by Indian women's collectives that are globally linked and have helped develop housing and sanitation improvements. The unit costs for such interventions are within the reach of all the key stakeholders. Global commitment is the only missing link.

The New Zealand Asthma and Allergy Cohort Study (NZA2CS): assembly, demographics and investigations

Background

Asthma and allergy are highly prevalent in industrialised countries. Longitudinal and cross-sectional studies have identified a number of potential risk factors for these conditions, including genetic and environmental factors, with significant gene-environment relationships. Birth cohort studies have been proposed as an important tool to explore these risk factors, particularly exposures in early life that are associated with later disease or protection from disease. This paper describes the establishment of a birth cohort in New Zealand.

Methods

A birth cohort was established in 1996 in Christchurch and Wellington and infants recruited between 1997–2001. Expectant mothers were recruited by midwives. Children and mothers have undergone assessment by serial questionnaires, environmental assessment including mould and allergen exposure, skin-prick testing, and at age six years are undergoing full assessment for the presence of asthma, atopy and allergic disease, including genetic assessment.

Results

A total of 1105 children have been recruited, and the retention rate at fifteen months was 91.4%. 15.2% of the children at recruitment have been identified as Maori. A positive family history of asthma, eczema or hay fever has been reported in 84% of children. All children have now been assessed at fifteen months and 685 children from the cohort have reached age six years and have completed the six year assessment.

Conclusion

The cohort is fully assembled, and assessment of children is well advanced, with good retention rates. The study is well placed to address many current hypotheses about the risk factors for allergic disease and asthma.

Fungi and indoor conditions in asthma patients

This study was carried out with 127 asthmatic patients and 127 controls, which aimed to compare and evaluate the environmental conditions in the homes of asthmatic patients and the control group. Air samples were obtained by using an air sampler and the mean mould colony counts were established. Aspergillus and Penicillium were the most common isolated species. No significant difference was observed with regard to various house conditions and the mean mould colony counts between the houses of patients and controls. The mould colony counts were found to be lower in houses with wooden parquet flooring. The odds ratio for stone floors vs. wood floors was 2.3 (95% CI 1.08-4.98) for mould growth.