Microbial exposures in moisture-damaged schools and associations with respiratory symptoms in students: A multi-country environmental exposure study.

Moisture-damaged buildings are associated with respiratory symptoms and underlying diseases among building occupants, but the causative agent(s) remain a mystery. We first identified specific fungal and bacterial taxa in classrooms with moisture damage in Finnish and Dutch primary schools. We then investigated associations of the identified moisture damage indicators with respiratory symptoms in more than 2700 students. Finally, we explored whether exposure to specific taxa within the indoor microbiota may explain the association between moisture damage and respiratory health. Schools were assessed for moisture damage through detailed inspections, and the microbial composition of settled dust in electrostatic dustfall collectors was determined using marker-gene analysis. In Finland, there were several positive associations between particular microbial indicators (diversity, richness, individual taxa) and a respiratory symptom score, while in the Netherlands, the associations tended to be mostly inverse and statistically non-significant. In Finland, abundance of the Sphingomonas bacterial genus and endotoxin levels partially explained the associations between moisture damage and symptom score. A few microbial taxa explained part of the associations with health, but overall, the observed associations between damage-associated individual taxa and respiratory health were limited.

DNA Sequence-Based Approach for Classifying the Mold Status of Buildings.

Dampness or water damage in buildings and human exposure to the resultant mold growth is an ever-present public health concern. This study provides quantitative evidence that the airborne fungal ecology of homes with known mold growth ("moldy") differs from the normal airborne fungal ecology of homes with no history of dampness, water damage, or visible mold ("no mold"). Settled dust from indoor air and outdoor air and direct samples from building materials with mold growth were examined in homes from 11 cities across dry, temperate, and continental climate regions within the United States. Community analysis based on the sequence of the internal transcribed spacer region of fungal ribosomal RNA encoding genes demonstrated consistent and quantifiable differences between the fungal ecology of settled dust in homes with inspector-verified water damage and visible mold versus the settled dust of homes with no history of dampness, water damage, or visible mold. These differences include lower community richness (padj = 0.01) in the settled dust of moldy homes versus no mold homes, as well as distinct community taxonomic structures between moldy and no mold homes (ANOSIM, R = 0.15, p = 0.001). We identified 11 Ascomycota taxa that were more highly enriched in moldy homes and 14 taxa from Ascomycota, Basidiomycota, and Zygomycota that were more highly enriched in no mold homes. The indoor air differences between moldy versus no mold homes were significant for all three climate regions considered. These distinct but complex differences between settled dust samples from moldy and no homes were used to train a machine learning-based model to classify the mold status of a home. The model was able to accurately classify 100% of moldy homes and 90% of no mold homes. The integration of DNA-based fungal ecology with advanced computational approaches can be used to accurately classify the presence of mold growth in homes, assist with inspection and remediation decisions, and potentially lead to reduced exposure to hazardous microbes indoors.

Building and indoor environmental quality assessment of Nigerian primary schools: A pilot study.

A total of 15 classrooms went through on-site assessments/inspections, including measurements of temperature (T), and concentrations of carbon monoxide (CO) and carbon dioxide (CO2 ). In addition, the level of surface biocontamination/cleaning effectiveness was assessed by measuring adenosine triphosphate (ATP) levels on students' desks. Based on the data, the quality of facilities in the buildings was low. Classroom occupancy exceeded ASHRAE 50 person/100 m2 standard in all cases indicating overcrowding. However, concentrations of CO2 remained below 1000 ppm in most classrooms. On the other hand, indoor T was above the recommended levels for thermal comfort in all classrooms. Maximum indoor CO was 6 ppm. Median ATP concentrations on the desk tops were moderately high in all schools. The use of open incinerators and power generator sets near classrooms, which was suspected to be the main source of CO, should be discouraged. Improved hygiene could be achieved by providing the students access to functioning bathroom facilities and cafeteria, and by effective cleaning of high contact surfaces such as desks. Although ventilation seems adequate based on CO2 concentrations, thermal comfort was not attained especially in the afternoon during extreme sunlight. Therefore, installing passive and/or mechanical cooling systems should be considered in this regard.

Effects of energy retrofits on Indoor Air Quality in multifamily buildings.

We assessed 45 multifamily buildings (240 apartments) from Finland and 20 (96 apartments) from Lithuania, out of which 37 buildings in Finland and 15 buildings in Lithuania underwent energy retrofits. Building characteristics, retrofit activities, and energy consumption data were collected, and Indoor Air Quality (IAQ) parameters, including carbon monoxide (CO), nitrogen dioxide (NO2 ), formaldehyde (CH2 O), selected volatile organic compounds (benzene, toluene, ethylbenzene, and xylenes (BTEX), radon, and microbial content in settled dust were measured before and after the retrofits. After the retrofits, heating energy consumption decreased by an average of 24% and 49% in Finnish and Lithuanian buildings, respectively. After the retrofits of Finnish buildings, there was a significant increase in BTEX concentrations (estimated mean increase of 2.5 µg/m3 ), whereas significant reductions were seen in fungal (0.6-log reduction in cells/m2 /d) and bacterial (0.6-log reduction in gram-positive and 0.9-log reduction in gram-negative bacterial cells/m2 /d) concentrations. In Lithuanian buildings, radon concentrations were significantly increased (estimated mean increase of 13.8 Bq/m3 ) after the retrofits. Mechanical ventilation was associated with significantly lower CH2 O concentrations in Finnish buildings. The results and recommendations presented in this paper can inform building retrofit studies and other programs and policies aimed to improve indoor environment and health.

Housing Satisfaction in Finland with Regard to Area, Dwelling Type and Tenure Status.

AIM: This study presents a comprehensive examination of housing satisfaction in Finland and how it associates with different types of residential area, dwelling and tenure status taking into account socio-demographic and socioeconomic variables. METHODS: Associations between housing satisfaction and types of residential area, dwelling and tenure status were analysed by multivariate logistic regression using questionnaire data from a random sample of Finnish households (response rate 44%, N=1,308). RESULTS: Respondents from rural areas and those living in houses were statistically significantly (p<0.05) more satisfied with indoor thermal conditions in summer than respondents living in city centres (OR 2.01) and apartments (OR 1.75), respectively. Homeowners were more satisfied with the dwelling (OR 3.19), indoor air quality (OR 1.73) and thermal conditions in winter (OR 2.63), and reported moisture or mould damage (OR 0.37) and neighbour noise disturbance (OR 0.60) less frequently than tenants. CONCLUSION: Based on this study, the most important factors determining differences in housing satisfaction were tenure status and type of the dwelling. In the context of housing policy development, these results warrant a special consideration of housing quality in rental apartments. The results can also be used for making comparative assessments (e.g. detecting areas of relative strengths or needing improvement) of multifamily buildings and residential areas.

Dampness, bacterial and fungal components in dust in primary schools and respiratory health in schoolchildren across Europe.

BACKGROUND: Respiratory health effects of damp housing are well recognised, but less is known about the effect of dampness and water damage in schools. The HITEA study previously reported a higher prevalence of respiratory symptoms in pupils from moisture damaged schools, but the role of specific microbial exposures remained unclear. OBJECTIVES: To study associations between school dampness, levels of fungal and bacterial markers, respiratory symptoms and lung function in children. METHODS: Primary schools in Spain, the Netherlands and Finland were selected on the basis of the observed presence (n=15) or absence (n=10) of moisture, dampness and/or mould. Settled dust was repeatedly sampled in 232 classrooms and levels of 14 different microbial markers and groups of microbes were determined. Parental reports of respiratory symptoms were available from 3843 children aged 6-12 years, of whom 2736 provided acceptable forced spirometry testing. Country-specific associations between exposure and respiratory health were evaluated by multilevel mixed-effects logistic and linear regression models and combined using random-effects meta-analysis. RESULTS: The prevalence of respiratory symptoms was higher in moisture damaged schools, being more pronounced in Finnish pupils. Effects on lung function were not apparent. Levels of microbial markers were generally higher in moisture damaged schools, varied by season and were lower in Finnish schools. Wheeze tended to be inversely associated with microbial levels. All other respiratory symptoms were not consistently associated with microbial marker levels. CONCLUSIONS: Health effects of moisture and microbial exposures may vary between countries, but this requires further study.

Dampness and mould in schools and respiratory symptoms in children: the HITEA study.

BACKGROUND: The adverse respiratory health effects of dampness and mould in the home have been extensively reported, but few studies have evaluated the health effects of such exposures in schools. OBJECTIVES: To assess the associations between dampness and mould in school buildings and respiratory symptoms among 6-12-year-old pupils in three European countries with different climates. METHODS: Based on information from self-reports and observations, we selected 29 primary schools with and 27 without moisture damage in Spain, the Netherlands and Finland. Information on respiratory symptoms and potential determinants was obtained using a parent-administered questionnaire among 6-12-year-old pupils. Country-specific associations between moisture damage and respiratory symptoms were evaluated using multivariable multilevel mixed effects logistic regression analysis. RESULTS: Data from 9271 children were obtained. Nocturnal dry cough was consistently associated with moisture damage at school in each of the three countries: OR 1.15; 95% CI 1.00 to 1.30 with p for heterogeneity 0.54. Finnish children attending a moisture damaged school more often had wheeze (OR 1.36; CI 1.04 to 1.78), nasal symptoms (OR 1.34; CI 1.05 to 1.71) and respiratory-related school absence (OR 1.50; CI 1.10 to 2.03). No associations with these symptoms were found in the Netherlands or Spain (p for heterogeneity <0.05). CONCLUSIONS: Moisture damage in schools may have adverse respiratory health effects in pupils. Finnish school children seem to be at higher risk, possibly due to quantitative and/or qualitative differences in exposure.

ATP as a marker for surface contamination of biological origin in schools and as a potential approach to the measurement of cleaning effectiveness.

To address the need for a quantitative approach to the measurement of cleaning effectiveness, related to biologically derived surface contamination, three commercially available adenosine triphosphate (ATP) test systems were used to collect multiple samples measured in relative light units (RLUs) from 27 elementary schools in the southwestern United States before and after a standardized cleaning protocol. The database consisted of 6480 ATP measurements from four critical surfaces (student desktops, cafeteria tabletops, and restroom sinks and stall doors). Data was assessed according to ranges of ATP values before and after cleaning. Results showed the potential for such data to provide the basis for a standardized approach to the measurement of cleaning effectiveness, based on detection and quantification of pollutant loads of biological origin, across critical surfaces in school building environments. It is anticipated that verification of this data in school buildings across different geographic and climatic regions will lead to the establishment of "acceptable" ranges of ATP values that can be used as a practice-based approach to improving cleaning practices and contributing to healthier school environments.

Indoor air quality guidelines from across the world: An appraisal considering energy saving, health, productivity, and comfort.

Buildings are constructed and operated to satisfy human needs and improve quality of life. Good indoor air quality (IAQ) and thermal comfort are prerequisites for human health and well-being. For their provision, buildings often rely on heating, ventilation, and air conditioning (HVAC) systems, which may lead to higher energy consumption. This directly impacts energy efficiency goals and the linked climate change considerations. The balance between energy use, optimum IAQ and thermal comfort calls for scientifically solid and well-established limit values for exposures experienced by building occupants in indoor spaces, including homes, schools, and offices. The present paper aims to appraise limit values for selected indoor pollutants reported in the scientific literature, and to present how they are handled in international and national guidelines and standards. The pollutants include carbon dioxide (CO2), formaldehyde (CH2O), particulate matter (PM), nitrogen dioxide (NO2), carbon monoxide (CO), and radon (Rn). Furthermore, acknowledging the particularly strong impact on energy use from HVAC, ventilation, indoor temperature (T), and relative humidity (RH) are also included, as they relate to both thermal comfort and the possibilities to avoid moisture related problems, such as mould growth and proliferation of house dust mites. Examples of national regulations for these parameters are presented, both in relation to human requirements in buildings and considering aspects related to energy saving. The work is based on the Indoor Environmental Quality (IEQ) guidelines database, which spans across countries and institutions, and aids in taking steps in the direction towards a more uniform guidance for values of indoor parameters. The database is coordinated by the Scientific and Technical Committee (STC) 34, as part of ISIAQ, the International Society of Indoor Air Quality and Climate.

Effects of classroom cleaning on student health: a longitudinal study.

BACKGROUND: School districts across the world have been grappling with how to keep their schools open, students healthy, and prevent the spread of viruses in their communities. OBJECTIVE: The aims of this study included assessing both (1) the effectiveness of enhanced classroom cleaning and disinfecting protocol on surface biocontamination and (2) the associations between surface biocontamination and student absence due to illnesses. METHODS: Cleaning effectiveness was assessed using quantitative adenosine triphosphate (ATP) measurements during a 10-week study period in a sample of 34 public schools (15,814 students), of a district located in the Western US. The schools were randomly assigned to 17 intervention schools implementing enhanced cleaning and disinfecting protocol and 17 control schools cleaning as usual. General estimating equations (GEEs) were used for modeling associations between ATP levels and weekly aggregates of student absences due to respiratory and gastrointestinal illnesses, which were recorded by the schools according to district wide protocol. RESULTS: The weekly average ATP levels on logarithmic scale were 5.02 (SD 0.53) and 5.26 (SD 0.48) in the intervention and control schools, respectively, where the difference is statistically significant (p < 0.001). The probability of weekly absence due to gastrointestinal illness was significantly associated with ATP levels (parameter estimate 1.16, 95% CI 1.01-1.34, per unit (log) increase of weekly average ATP), where the model accounts for student level, gender, ethnic group, and socioeconomic status as well as for school level attendance, total absence ratio, and ventilation adequacy in classrooms. Associations were not found between ATP levels and weekly probability of any absence, or absence due to respiratory illness. SIGNIFICANCE: Enhanced cleaning resulted in a significantly lower level of biocontamination on desktops in the intervention group. In addition, a statistically significant association was established between ATP levels on classroom desks and probability of absence due to gastrointestinal illness. IMPACT: We found that enhanced cleaning protocol, including bi-weekly cleaning of classroom desks, as well as training of custodians and teachers, monitoring of effectiveness, and feedback, yielded a moderate but statistically significantly lower level of biocontamination on desktops, indicated by quantitative ATP monitoring. Within the range of weekly average desktop ATP levels observed, the probability of reported absence due to gastrointestinal illness is estimated to increase from 0.021 to 0.026. Based on the results, enhanced surface cleaning and monitoring its effectiveness is a possible district, state, or even national level policy to support healthy school environments.

Practitioner-driven research for improving the outcomes of mold inspection and remediation.

This commentary is intended to provide a research roadmap for utilizing recent chemical and molecular-biological technological advances for addressing dampness and mold in buildings. The perspective is unique in that both the mold industry practitioners and academic researchers drive the questions. Research needs were derived from a 2018 international workshop attended by practitioners, researchers and governmental representatives, where challenges and opportunities in the mold remediation and restoration field were discussed focusing on the need to develop new tools that improve building diagnosis and clearance certification for mold inspectors and remediators. Suggestions are made on how new technologies surrounding DNA-based sequence analysis for fungal and bacterial identification and real-time chemical sensor technology can be leveraged by practitioners to improve inspection and remediation. The workshop put into effect a logical progression to distill and extract practice-based implications and encourage the process of transfer of the science to practice. Goals for the workshop, and this subsequent paper, are also centered on encouraging US government-funding agencies to better position and define research on the built environment geared for end-user scientists and practitioners to better explore practical solutions to dampness and mold in indoor environments. By facilitating the workshop forum and targeting industry, field practitioners, and government agencies, a sharing of needed commonalities may be infused into future research agendas and outreach efforts.

Occurrence of respiratory viruses on school desks.

BACKGROUND: Schools represent high occupancy environments and well-documented high-risk locations for the transmission of respiratory viruses. The goal of this study was to report on the area density, occurrence, and type of respiratory viruses on desks in primary school classrooms. METHODS: Quantitative reverse transcription polymerase chain reaction (qPCR) techniques were employed to measure nucleic acid area densities from a broad range of human adenoviruses and rhinoviruses, as well as coronavirus OC43, influenza A, and norovirus GI. Every two weeks, virus monitoring was conducted on the desks of four primary school classrooms in Colorado, USA, during the 2019 respiratory virus season. RESULTS: DNA and RNA from respiratory viruses and norovirus were recovered from more than 20% of the desks sampled; occurrence patterns that indicate a greater than 60% probability of encountering any virus, if more than five desks were occupied in a day. Rhinoviruses and adenoviruses were the most commonly detected viruses as judged by the composite of occurrence and number of gene copies recovered. Desktop adenosine triphosphate monitoring did not predict the recovery of viral genomic materials on desks. School desks can be commonly contaminated with respiratory viruses. CONCLUSIONS: Genomic surveys of the identity, distribution and abundance of human viruses on "high-touch" surfaces, can help inform risk assessments, design cleaning interventions, and may be useful for infection surveillance.

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. METHODS: The data collection and response system was tested with a sample of 3000 adults (one per household), who were randomly selected from the Finnish Population Register Centre. Spatial information about the exact location of the residences (i.e. coordinates) was included in the database inquiry. People could participate either by completing and returning a paper questionnaire or by completing the same questionnaire via the Internet. The respondents did not receive any compensation for their time in completing the questionnaire. RESULTS: This article describes the data collection and response system and presents the main results of the population-based testing of the system. A total of 1312 people (response rate 44%) answered the questionnaire, though only 80 answered via the Internet. A third of the respondents had indicated they wanted feedback. Albeit a majority (>90%) of the respondents reported being satisfied or quite satisfied with their residence, there were a number of prevalent housing issues identified that can be related to health and safety. CONCLUSIONS: The collected database can be used to evaluate the quality of the housing stock in terms of occupant health and safety, and to model its association with occupant health and well-being. However, it must be noted that all the health outcomes gathered in this study are self-reported. A follow-up study is needed to evaluate whether the occupants acted on the feedback they received. Relying solely on an Internet-based questionnaire for collecting data would not appear to provide an adequate response rate for random population-based surveys at this point in time.

Development of an education integrated design framework for the physical space of nursing homes in relation to life expectancy of the older people.

The purpose of this research is to find design variables effective on education integration with physical spaces of nursing homes in association with life expectancy of older people. Delphi technique was used to obtain the design variables by which the education integration with physical spaces of nursing homes can be achieved. Subsequently, in order to investigate the modifying effect of education integrated physical space on life expectancy of the elderly, questionnaires were sent to 50 local researchers and experts in the field of ageing. Results showed a significant and positive correlation between education integrated physical space and life expectancy indicators (p < .05). The results suggest that as per expert opinions, designing a physical space integrated with education could increase the life expectancy of older people.

Healthy people in healthy premises: the Finnish Indoor Air and Health Programme 2018-2028.

Clean and fresh indoor air supports health and well-being. However, indoor air can contain pollutants that can cause a variety of symptoms and reduce well-being. Individual exposure agents can also increase the risk of certain diseases. Finns have taken major steps to improve the quality of indoor air for several decades. The primary focus of these activities has been the prevention and reduction of exposure to poor indoor air quality through guidance and regulation directing remediation of damaged buildings. Nevertheless, reported symptoms related to poor indoor air quality are common in Finland. In addition to exposure to indoor air pollutants, this may be partly due to the lively public discussion on the health risks caused by poor indoor air quality, conflicting views between experts, and mistrust towards public authorities, building owners and builders. Because of the scale of the indoor air problems in Finland, people's needs for reliable information and support, and the major costs involved, there is a call for new evidence-based methods, perspectives and solutions. Therefore, the Finnish Institute for Health and Welfare initiated the Finnish Indoor Air and Health Programme 2018-2028 together with a number of collaborators and stakeholders. The primary, long-term objective of the programme is to reduce hazards to health and well-being linked to indoor environments in Finland. To fulfill this objective, the programme will focus on the promotion of human health and well-being, the prevention of hazards, improved communication and engage the whole health-care sector to manage better patients´ symptoms and complaints. The 10-year Finnish Indoor Air and Health Programme consists of four areas that aim (1) to increase understanding of the effects of indoor environments on health and well-being; (2) to develop the management of problems linked to indoor environments; (3) to improve the treatment and working and functional capacity of people with symptoms and illnesses; and (4) to strengthen the competence in matters related to indoor environments. The progress of the programme and reaching the predefined, quantitative goals will be monitored throughout the programme.

Comparing bacterial, fungal, and human cell concentrations with rapid adenosine triphosphate measurements for indicating microbial surface contamination.

BACKGROUND: The goal of this study was to test for associations between adenosine triphosphate (ATP) content and microbial concentrations on desk surfaces in school classrooms. METHODS: ATP bioluminescence and quantitative polymerase chain reaction (qPCR) techniques were employed to measure total bacterial, fungal, and human cell concentrations on 66 high-traffic desks spread across 9 schools: 3 in Connecticut (CT) and 6 in Oklahoma (OK). In CT, 6 samples were taken from each desk, 1 precleaning and 5 postcleaning (after 30 minutes, 1 day, 3 days, 7 days, and 21 days). In OK, samples were taken immediately before and after cleaning each desk. RESULTS: Based on simple linear regression analyses, ATP values were good predictors of microbial concentrations (r = 0.8, P = .003) in both CT school postcleaning samples and OK pre- and postcleaning samples (r = 0.7, P = .00002). However, biomass reductions measured after cleaning were 1.5-2 times greater when measured by ATP than by qPCR (P = .007). CONCLUSIONS: Overall, ATP bioluminescence measurements correlate with qPCR-based surface measurements on school desks but may overestimate the physical removal of bacteria and fungi due to cleaning.

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. Based on technical monitoring, remediation was successful in three cases, with partial improvement noted in three cases, whereas no remediation was conducted in one case. Based on microbial monitoring, improvement was detected in one, partial improvement in two and no improvement in two cases, whereas no follow-up was conducted in two cases. Health effect studies (mainly self-reported health status) showed improvement in one case, partial improvement in two cases, and no improvement in two cases, whereas no follow-up was conducted in one case, and in one case, follow-up failed due to low response rate. The results illustrate that it is possible to monitor the effects of remediation using various metrics. However, in some cases, no improvement could be observed in IAQ or occupant health, even if the remediation was considered technically successful, i.e. the remediation was fully completed as recommended. This could be due to many reasons, including: 1) all damage may not have been addressed adequately; 2) IAQ or health may not have been perceived improved regardless of remediation; and/or 3) the methods used may not have been sensitive/specific enough to detect such improvement within the 6-12 months follow-up periods after completion of the remediation. There is a need to further develop tools for monitoring and assessment of the success of moisture damage remediation in buildings.

Indoor thermal environment, air exchange rates, and carbon dioxide concentrations before and after energy retro fits in Finnish and Lithuanian multi-family buildings.

Impacts of energy retrofits on indoor thermal environment, i.e. temperature (T) and relative humidity (RH), as well as ventilation rates and carbon dioxide (CO2) concentrations, were assessed in 46 Finnish and 20 Lithuanian multi-family buildings, including 39 retrofitted case buildings in Finland and 15 in Lithuania (the remaining buildings were control buildings with no retrofits). In the Finnish buildings, high indoor T along with low RH levels was commonly observed both before and after the retrofits. Ventilation rates (l/s per person) were higher after the retrofits in buildings with mechanical exhaust ventilation than the corresponding values before the retrofits. Measured CO2 levels were low in vast majority of buildings. In Lithuania, average indoor T levels were low before the retrofits and there was a significant increase in the average T after the retrofits. In addition, average ventilation rate was lower and CO2 levels were higher after the retrofits in the case buildings (N=15), both in apartments with natural and mixed ventilation. Based on the results, assessment of thermal conditions and ventilation rates after energy retrofits is crucial for optimal indoor environmental quality and energy use.