Indoor environmental quality in school buildings, and the health and wellbeing of students.

Poor indoor environmental quality (IEQ) in classrooms may be a risk for health symptoms and cause absence from school. We conducted a comprehensive study in order to assess the connection between IEQ in Finnish elementary school buildings and the health and academic performance of sixth grade students. The specific aim of the present paper was to study the school- or grade-level prevalence of symptoms in relation to IEQ.

Microbial secondary metabolites in school buildings inspected for moisture damage in Finland, The Netherlands and Spain.

Secondary metabolites produced by fungi and bacteria are among the potential agents that contribute to adverse health effects observed in occupants of buildings affected by moisture damage, dampness and associated microbial growth. However, few attempts have been made to assess the occurrence of these compounds in relation to moisture damage and dampness in buildings. This study conducted in the context of the HITEA project (Health Effects of Indoor Pollutants: Integrating microbial, toxicological and epidemiological approaches) aimed at providing systematic information on the prevalence of microbial secondary metabolites in a large number of school buildings in three European countries, considering both buildings with and without moisture damage and/or dampness observations.

High indoor microbial levels are associated with reduced Th1 cytokine secretion capacity in infancy.

Background: Exposure to microbes and their components may affect the maturation of the immune system. We examined the association of house dust microbial content with cytokine-producing capacity at birth and at the age of 1 year.

Methods: Production of TNF-α, IFN-γ, IL-5, IL-8 and IL-10 at birth (n = 228) and at the age of 1 year (n = 200) following 24- and 48-hour whole-blood stimulation with staphylococcal enterotoxin B (SEB), lipopolysaccharide and the combination of phorbol ester and ionomycin was measured.

Concentrations and diversity of microbes from four local bioaerosol emission sources in Finland.

Microbial particles can readily be released into the air from different types of man-made sources such as waste operations. Microbiological emissions from different biological sources and their dispersion may be an issue of concern for area planning and for nearby residents. This study was designed to determine the concentrations and diversity of microbiological emissions from four different man-made source environments: waste center with composting windrows, sewage treatment plant, farming environment, and cattle manure spreading.

Molecular profiling of fungal communities in moisture damaged buildings before and after remediation--a comparison of culture-dependent and culture-independent methods.

Background: Indoor microbial contamination due to excess moisture is an important contributor to human illness in both residential and occupational settings. However, the census of microorganisms in the indoor environment is limited by the use of selective, culture-based detection techniques. By using clone library sequencing of full-length internal transcribed spacer region combined with quantitative polymerase chain reaction (qPCR) for 69 fungal species or assay groups and cultivation, we have been able to generate a more comprehensive description of the total indoor mycoflora.

Determinants of stimulated peripheral blood cytokine production among farming women.

Farming environment and environmental exposure to microbial agents have been suggested to promote favorable development of immune system in children and protect against allergic diseases. However, effects of farm exposure on adult immune responses are less clear. Aim of the present study was to examine associations of farm related factors and measured microbial exposure with stimulated production of interferon-gamma (IFN-γ) and interleukin-4 (IL-4) in peripheral blood samples among farming women.

Odour annoyance and physical symptoms among residents living near waste treatment centres.

Waste treatment processes produce odours and biological emissions to the environment, but their health effects are controversial. The aim of our study was to assess odour-associated self-reported physical symptoms among residents living near waste treatment centres. The study was conducted in the surroundings of five large-scale Finnish waste treatment centres with composting plants.

Evaluating housing quality, health and safety using an Internet-based data collection and response system: a cross-sectional study.

Background: Typically housing and health surveys are not integrated together and therefore are not representative of population health or national housing stocks. In addition, the existing channels for distributing information about housing and health issues to the general public are limited. The aim of this study was to develop a data collection and response system that would allow us to assess the Finnish housing stock from the points of view of quality, health and safety, and also to provide a tool to distribute information about important housing health and safety issues.

Determination of bacterial load in house dust using qPCR, chemical markers and culture.

In this study, we developed two novel qPCR-assays for the detection of bacteria in house dust; one that determines the total bacterial amount and another that detects Gram-positive and Gram-negative bacteria separately. The methods were tested in silico and in vitro with microbial strains and vacuum cleaner dust samples, and validated in relation to culture and chemical marker analysis. We also compared the results of these three types of methods (qPCR, culture and chemical marker analysis) in 211 house dust samples from farming and non-farming environments.

Odor annoyance near waste treatment centers: a population-based study in Finland.

Decomposition of biodegradable waste in municipal waste centers may produce odor emissions and subsequently cause discomfort to nearby residents. The public health importance of the resulting nuisance has not been sufficiently characterized. The aim of this study was to study the perception and annoyance of waste odor among residents in relation to distance from the large-scale source.

Immunotoxicological properties of airborne particles at landfill, urban and rural sites and their relation to microbial concentrations.

We investigated the immunotoxicological activity of airborne particles in three different environments during 11 months. Specifically, we analyzed the relation of the immunotoxicological activity to microbial concentrations. During the study period, samples from a landfill, an urban and a rural site were collected on filters once a month.

The effect of ozonization on furniture dust: microbial content and immunotoxicity in vitro.

Moisture and mold problems in buildings contaminate also the furniture and other movable property. If cleaning of the contaminated furniture is neglected, it may continue to cause problems to the occupants even after the moisture-damage repairs. The aim of this study was to determine the effectiveness of high-efficiency ozone treatment in cleaning of the furniture from moisture-damaged buildings.

The occupant as a source of house dust bacteria.

Background: Markers for microbial groups are commonly measured in house dust samples to assess indoor exposure to microbes in studies on asthma and allergy. However, little is known about the sources of different microbes. A better understanding of the nature and origin of microbes present in the immediate environment of human beings is crucial if one wants to elucidate protective as well as adverse effects on human health.

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

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

Methods: Building inspection was performed by building engineers in the homes of 396 children, and the children were followed up with questionnaires from birth to the age of 18 months.

Microbial content of house dust samples determined with qPCR.

This study was designed to produce information about microbial concentrations using qPCR and their variation in different seasons and home environments with analyses of two types of house dust samples. Also the correlations between the two types of samples and the reproducibility of the parallel subsamples were studied. Two types of vacuumed house dust samples, rug dust and vacuum cleaner bag dust, were collected in 5 normal urban homes in four different seasons (N=20+20).

Predominance of Gram-positive bacteria in house dust in the low-allergy risk Russian Karelia.

Simple living conditions and farming environment have been associated with reduced risk for allergic diseases such as atopy and asthma but the factors responsible for this effect remain unresolved. We examined the bacterial composition of house dusts obtained from Finnish and Russian Karelia, two adjacent areas with high and low occurrence of atopic diseases respectively. Two dust mixes, both composed of 10 randomly selected dust samples from 349 Finnish and 417 Russian Karelian households were studied for bacterial biomarkers (DNA, Limulus-active endotoxin, 3-OH fatty acids, muramic acid) and for 16S rRNA gene sequences.

Indoor air particles and bioaerosols before and after renovation of moisture-damaged buildings: the effect on biological activity and microbial flora.

Many building-related health problems coincide with moisture damage and mold growth within a building. Their elimination is assumed to improve indoor air quality. The aim of this study was to follow the success of remediation in two individual buildings by analyzing the microbial flora and immunotoxicological activity of filter samples.

Monitoring success of remediation: seven case studies of moisture and mold damaged buildings.

Based on seven case studies of buildings that underwent different degrees of moisture and mold damage remediation, we aimed to develop methodology for assessment of the success of the remediation process. Methods used in gauging the success included technical monitoring of performance of building structures and heating, ventilation and air conditioning (HVAC) systems, microbial monitoring of indoor air quality (IAQ), and health effects studies of building occupants. The assessment was based on measurable change in the situations before and after remediation.

Quantitative PCR analysis of fungi and bacteria in building materials and comparison to culture-based analysis.

Prolonged moisture on building materials can lead to microbial growth on them. Microbes can emit spores, metabolites and structural parts into the indoor air and thus, cause adverse health effects of people living and working in these buildings. So far, culture methods have been used for assessment of microbial contamination of building materials.

Diversity and seasonal dynamics of bacterial community in indoor environment.

Background: We spend most of our lives in indoor environments and are exposed to microbes present in these environments. Hence, knowledge about this exposure is important for understanding how it impacts on human health. However, the bacterial flora in indoor environments has been only fragmentarily explored and mostly using culture methods.

Characterizing microbial exposure with ergosterol, 3-hydroxy fatty acids, and viable microbes in house dust: determinants and association with childhood asthma.

The authors assessed determinants of ergosterol, 3-OH fatty acids (FAs), and viable microbes in vacuum cleaner dust, and investigated the association between these microbial markers and childhood asthma. The authors studied the homes of 36 children who were new cases of childhood asthma and the homes of 36 controls. Home characteristics explained 34% to 44% of the variation in levels of different microbial groups.

Effects of co-culture of amoebae with indoor microbes on their cytotoxic and proinflammatory potential.

Free-living amoebae are ubiquitous environmental protozoa found in both natural and man-made environments, including moisture-damaged buildings. Furthermore, the interaction between amoebae and bacteria has been shown to enhance the virulence and pathogenicity of some bacteria. While the inhabitants of moisture damaged buildings are known to be at risk of suffering adverse health effects, the exact causative agents and mechanisms are still obscure.

Elements that contribute to healthy building design.

Background: The elements that contribute to a healthy building are multifactorial and can be discussed from different perspectives.

Objectives: WE PRESENT THREE VIEWPOINTS OF DESIGNING A HEALTHY BUILDING: the importance of sustainable development, the role of occupants for ensuring indoor air quality, and ongoing developments related to indoor finishes with low chemical emissions and good fungal resistance.

Discussion: Sustainable design rediscovers the social, environmental, and technical values of pedestrian and mixed-use communities, using existing infrastructures including "main streets" and small-town planning principles and recapturing indoor-outdoor relationships.