Dampness in buildings as a risk factor for health effects, EUROEXPO: a multidisciplinary review of the literature (1998-2000) on dampness and mite exposure in buildings and health effects

Indoor air pollutants and respiratory symptoms among residents of an informal urban settlement in Uganda: A cross-sectional study

BACKGROUND

Indoor air pollutants (IAP) and household conditions such as dampness, crowding and chemical exposures have been associated with acute and chronic respiratory infections. In Uganda, literature on the effects of IAP on respiratory outcomes in informal settlements is limited.

METHODS

We describe the baseline household characteristics of 284 adults and their children in an informal settlement in Uganda from April to May 2022. We monitored same-day indoor concentrations of particulate matter PM2.5, PM10, Carbon monoxide (CO), relative humidity %, and temperature from 9 am to 2 pm and interviewed caregivers/mothers about their respiratory symptoms and those of their children in the previous 30 days. We employed robust Poisson regressions to evaluate the associations between indoor air indicators and respiratory health symptoms.

RESULTS

Approximately 94.7% of households primarily used biomass fuels and 32.7% cooked from inside their dwelling rooms. The median PM2.5, PM10 and CO levels were 49.5 (Interquartile range (IQR) = 31.1,86.2) μg/m3, 73.6 (IQR = 47.3,130.5) μg/m3 and 7.70 (IQR = 4.1,12.5) ppm respectively. Among adults, a 10 unit increase in PM2.5 was associated with cough (Prevalence Ratio (PR) = 3.75, 95%CI 1.15-1.55). Dwelling unit dampness was associated with phlegm (PR = 2.53, 95%CI = 1.39-4.61) and shortness of breath (PR = 1.78, 95% CI 1.23-2.54) while cooking from outside the house was protective against shortness of breath (PR = 0.62, 95% CI = 0.44-0.87). In children, dampness was associated with phlegm (PR = 13.87, 95% CI 3.16-60.91) and cough (PR = 1.62, 95% CI 1.12-2.34) while indoor residual spraying was associated with phlegm (PR = 3.36, 95%CI 1.71-6.61).

CONCLUSION

Poor indoor air conditions were associated with respiratory symptoms in adults and children. Efforts to address indoor air pollution should be made to protect adults and children from adverse health effects.

Effects of indoor summer dehumidification and winter humidification on the physiological and subjective responses of the elderly

The purpose of this study was to clarify the physiological and subjective responses of the elderly to dehumidification in a humid summer and humidification in a dry winter compared with the young. Sixteen elderly and sixteen young subjects participated in the dehumidification experiment (DE) and 13 elderly and 15 young subjects participated in the humidification experiment (HE). The air temperature in the climate chamber was set at 28 °C, and humidity was decreased from 70% relative humidity (RH) to 50% RH for 90 min in the DE. The air temperature was set at 25 °C, and the humidity was increased from 30% RH to 50% RH for 90 min in the HE. Skin temperature, body weight, transepidermal water loss (TEWL), skin hydration state, saccharin clearance time (SCT), and blinking frequency were measured during exposure; whereby we evaluated humidity sensation, thermal sensation, and thermal comfort. Dehumidification caused a significant decrease in skin temperature in both age groups owing to greater insensible perspiration. Humidification significantly shortened the SCT in both age groups. TEWL increased significantly in the DE and decreased in the HE. For the physiological responses (skin temperature, skin physiology, SCT, and blinking frequency) to dehumidification and humidification, no distinct differences between the age groups were observed. However, subjective responses suggested that the elderly were less sensitive to humidity differences than the young in both the DE and HE.

Occurrence of fungal spores in drinking water: A review of pathogenicity, odor, chlorine resistance and control strategies

Fungi in drinking water have been long neglected due to the lack of convenient analysis methods, widely accepted regulations and efficient control strategies. However, in the last few decades, fungi in drinking water have been widely recognized as opportunity pathogens that cause serious damage to the health of immune-compromised individuals. In drinking water treatment plants, fungal spores are more resistant to chlorine disinfection than bacteria and viruses, which can regrow in drinking water distribution systems and subsequently pose health threats to water consumers. In addition, fungi in drinking water may represent an ignored source of taste and odor (T&O). This review identified 74 genera of fungi isolated from drinking water and presented their detailed taxonomy, sources and biomass levels in drinking water systems. The typical pathways of exposure of water-borne fungi and the main effects on human health are clarified. The fungi producing T&O compounds and their products are summarized. Data on free chlorine or monochloramine inactivation of fungal spores and other pathogens are compared. At the first time, we suggested four chlorine-resistant mechanisms including aggregation to tolerate chlorine, strong cell walls, cellular responses to oxidative stress and antioxidation of melanin, which are instructive for the future fungi control attempts. Finally, the inactivation performance of fungal spores by various technologies are comprehensively analyzed. The purpose of this study is to provide an overview of fungi distribution and risks in drinking water, provide insight into the chlorine resistance mechanisms of fungal spores and propose approaches for the control of fungi in drinking water.

An investigation of child health in relation to housing renovations for a disadvantaged immigrant population in Malmö, Sweden

Aims:

The aim of the study was to describe child health in relation to housing renovations in more than 800 rental units, consisting of repairs of dilapidated kitchens and bathrooms, in the disadvantaged neighbourhood of Herrgården in Rosengård, Malmö, Sweden.

Methods:

Data on housing conditions and self-reported health were collected during home visits to families living in Herrgården (building renovations area) and a comparison area (neighbouring Törnrosen, with generally better housing conditions). At baseline, 130 families with 359 children participated, while 51 families with 127 children participated at follow-up. All data were collected between 2010 and 2012. Additionally, regional register data on health-care usage/in- and outpatient contacts within the public health-care system between 2008 and 2013 were also collected for all 8715 children registered as living in the two areas.

Results:

Self-reported health seemed to somewhat improve in both areas, with 74% versus 86% and 78% versus 88% reporting good or very good health in Herrgården and in the comparison area at baseline and follow-up, respectively. In Herrgården, crowdedness increased, while it decreased in the comparison area. The number of health-care contacts remained stable over time in Herrgården, while it decreased in the comparison area.

Conclusions:

Partial housing renovations did not seem to result in clear health improvements as measured with the indicators used in the present study. This could possibly be due to persisting health effects due to increased crowdedness or persisting poor housing conditions, as only kitchens and bathrooms were renovated.

Interaction effect of prenatal and postnatal exposure to ambient air pollution and temperature on childhood asthma

BACKGROUND

Although mounting evidence has associated air pollution and environmental temperature with children's health problems, it is unclear whether there is an interaction between these factors on childhood asthma.

OBJECTIVES

To explore the effects of temperature-pollution interactions during pre- and post-natal periods on asthma among pre-schoolers.

METHODS

A retrospective cohort study of 39,782 pre-schoolers was performed during 2010-2012, in seven cities in China. Exposure to three temperature indicators (TI) and three critical ambient air pollutants, including particulate matter with aerodynamic diameter ≤ 10 μm (PM₁₀), sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) as proxies of industrial and vehicular air pollution, was estimated by an inverse distance weighted (IDW) method. Two-level logistical regression analysis was used to examine the association between both pre- and post-natal exposure and childhood asthma in terms of odds ratio (OR) and 95 % confidence interval (CI).

RESULTS

Asthma prevalence in pre-schoolers at age of 3-6 years (6.9 %) was significantly associated with traffic-related air pollutant (NO₂) exposure, with ORs (95 % CI) of 1.17 (1.06, 1.28), 1.19 (1.05-1.34) and 1.16 (1.03-1.31) for an IQR increase in NO₂ exposure during lifetime, pregnancy, and entire postnatal period respectively. Furthermore, childhood asthma was positively associated with exposure to increased temperature during lifetime, pregnancy, and entire postnatal period with ORs (95 % CI) = 1.89 (1.66, 2.16), 1.47 (1.34, 1.61), and 1.15 (1.11, 1.18) respectively, while was negatively associated with decreased temperatures. Childhood asthma was positively related with exposure to extreme heat days (EHD) during postnatal period particularly in first year of life respectively with ORs (95 % CI) = 1.23 (1.04, 1.46) and 1.26 (1.07, 1.47), but was not related with extreme cold days (ECD) exposure. A combination of high air pollutant levels and high temperatures significantly increased the risk of asthma during both pre- and post-natal periods. Strikingly, we found a significantly positive interaction of temperature and PM₁₀ or SO₂ on asthma risk among boys and younger children.

CONCLUSIONS

Prenatal and postnatal exposure to ambient air pollution and high temperatures are independently and jointly associated with asthma risk in early childhood.

Effect of prenatal and postnatal exposure to home renovation on the risk of common cold in preschool children

Common cold is usually considered to be associated with outdoor climate, but the evidence linking with indoor environmental factors is lacking. The role of indoor renovations during which critical timing window on childhood common cold remains unclear. Therefore, we investigated the effect of exposure to new furniture and/or redecoration during prenatal and postnatal periods on the occurrence and duration of common cold in preschool children. We conducted a retrospective cohort study of 39 782 children aged 3-6 years in seven cities of China. The occurrence and duration of common cold in children, and their lifetime exposures to indoor new furniture and redecoration (including pregnancy, the first year of life, and after one year old) were assessed using a questionnaire administered by the parents. Associations between high frequency (>5 colds) and long duration (≥2 weeks per cold) of common cold during past 12 months and exposure to indoor new furniture/redecoration were examined by logistic regression models in terms of odds ratio (OR) and 95% confidence interval (CI). We found that the prevalence of high frequency and long duration of common cold in preschool children in China were, respectively, 9.2% and 11.9%. Frequent common cold was significantly associated with exposure to indoor new furniture/redecoration during pregnancy, first year, and after 1 year old, respectively, with the ORs (95% CI) = 1.25 (1.12-1.39), 1.11 (1.00-1.25), and 1.09 (1.01-1.18). Furthermore, childhood long duration per cold was associated with exposure to indoor new furniture/redecoration during pregnancy with OR (95% CI) of 1.14 (1.03-1.25) but not with postnatal exposure. We identified that prenatal exposure to home renovation was more critical than postnatal exposure for an increased risk of high frequency and long duration of common cold. Sensitivity analysis showed that the association between prenatal exposure to indoor renovations and the risk of childhood common cold was consistent and robust, and the associations were modified by some personal and indoor environmental factors. Our findings indicated that prenatal and postnatal exposure to home renovation played an important role in the risk of childhood common cold, supporting the hypothesis of "fetal origin of childhood infection."

Evaluation of Children's Thermal Environment in Nursery School: Through the Questionnaire and Measurement of Wearable Sensors Approach

Due to psychological and physical differences, children are more vulnerable to the influence of the surrounding environment than adults. A nursery school in Japan was selected as the research object. The actual thermal environment of children aged 1 to 5 in the classroom was evaluated based on measured data in winter and summer. Through a questionnaire survey of nursery teachers, this paper analyzed and compared the relationship between teachers’ thermal adaptation behavior and children’s thermal sensation. Compared with the traditional fixed-points measurement method, a method of wearable sensors for children was proposed to measure the indoor temperature distribution. The traditional measurement results showed that 73% of classroom indoor temperatures and humidity do not meet the thermal comfort standard stipulated by the government. The method proposed in this paper indicates that: (1) nursery teachers’ thermal adaptation behavior may not be based on children’s thermal sensations; (2) solar radiation and weather context could lead to uneven indoor horizontal temperature distribution, hence, specific attention should be paid to the thermal environment when children move to the window side; and (3) the density of occupants causes the temperature around the human body to be relatively high. We suggest that teachers improve the thermal comfort of gathered children through thermal adaptive behaviors. The results of the study provide valuable information for nursery managers to formulate effective indoor thermal environment strategies from the perspective of children.

Melinacidin-Producing Acrostalagmus luteoalbus, a Major Constituent of Mixed Mycobiota Contaminating Insulation Material in an Outdoor Wall

Occupants may complain about indoor air quality in closed spaces where the officially approved standard methods for indoor air quality risk assessment fail to reveal the cause of the problem. This study describes a rare genus not previously detected in Finnish buildings, Acrostalagmus, and its species A. luteoalbus as the major constituents of the mixed microbiota in the wet cork liner from an outdoor wall. Representatives of the genus were also present in the settled dust in offices where occupants suffered from symptoms related to the indoor air. One strain, POB8, was identified as A. luteoalbus by ITS sequencing. The strain produced the immunosuppressive and cytotoxic melinacidins II, III, and IV, as evidenced by mass spectrometry analysis. In addition, the classical toxigenic species indicating water damage, mycoparasitic Trichoderma, Aspergillus section Versicolores, Aspergillus section Circumdati, Aspergillus section Nigri, and Chaetomium spp., were detected in the wet outdoor wall and settled dust from the problematic rooms. The offices exhibited no visible signs of microbial growth, and the airborne load of microbial conidia was too low to explain the reported symptoms. In conclusion, we suggest the possible migration of microbial bioactive metabolites from the wet outdoor wall into indoor spaces as a plausible explanation for the reported complaints.

Why Does a High Humidity Level Form in Low-Income Households Despite Low Water Vapor Generation?

This study uses long-term field measurements to quantify the indoor humidity generation rates of low-income households vulnerable to condensation and related problems. We found that the mean internal moisture excess of low-income households in Korea was 4.69 g/m3 higher than those of prior studies. Indoor water vapor generation rates of various activities considering the life style of low-income households were also quantified. The moisture generation rates of the shower and bath were 125.3 g/event and 51.1 g/event, respectively, and showed a similar or lower value compared to the existing results. The moisture generation rate of cooking showed the largest difference due to the residential characteristics of low-income households, such as cooking less frequently due to meal delivery services from the welfare center and the lower number of residents per household. Even though the moisture generation rates of low-income households for certain activities showed lower values compared to the results of prior studies, the indoor conditions were very humid due to the lower ventilation rates and studio-type open floor plan.

Associations of household dampness with asthma, allergies, and airway diseases among preschoolers in two cross-sectional studies in Chongqing, China: Repeated surveys in 2010 and 2019

Many studies have investigated the associations between household damp indicators, and allergies and respiratory diseases in childhood. However, the findings are rather inconsistent. In 2010, we conducted a cross-sectional study of preschoolers aged three-six years in three urban districts of Chongqing, China. In 2019, we repeated this cross-sectional study with preschoolers of the same ages and districts. Here, we selected data for 2935 and 2717 preschoolers who did not change residences since birth in the 2010 and 2019 studies, respectively. We investigated associations of household damp indicators with asthma, allergic rhinitis, pneumonia, eczema, wheeze, and rhinitis in childhood in the two studies. The proportions of residences with household damp indicators and the prevalence of the studied diseases (except for allergic rhinitis) were significantly lower in 2019 than in 2010. In the two-level (district-child) logistic regression analyses, household damp exposures that showed by different indicators were significantly associated with the increased odds of lifetime-ever asthma (range of adjusted odds ratio (AOR): 1.69-3.50 in 2019; 1.13-1.90 in 2010), allergic rhinitis (1.14-2.39; 0.67-1.61), pneumonia (1.09-1.64; 1.21-1.59), eczema (0.96-1.83; 0.99-1.56), wheeze (1.64-2.79; 1.18-1.91), rhinitis (1.43-2.71; 1.08-1.58), and current (in the past 12 months before the survey) eczema (0.46-2.08; 0.99-1.48), wheeze (0.97-2.86; 1.26-2.07) and rhinitis (1.34-2.25; 1.09-1.56) in most cases. The increased odds ratios (ORs) of most diseases had exposure-response relationships with the cumulative number (n) of household damp indicators in the current and early residences. Our results indicated household damp exposure could be a risk factor for childhood allergic and respiratory diseases, although the magnitudes of these effects could be different in different studies.

Current challenges for shaping the sustainable and mold-free hygienic indoor environment in humid regions

Indoor mold grows ubiquitously in humid areas and can affect occupants' health. To prevent indoor mold contamination, one of the key measures suggested by the World Health Organisation and United States Environmental Protection Agency is to maintain an indoor relative humidity (RH) level below 75% or at 30-60%, respectively. However, in tropical and subtropical areas, maintaining these suggested RH levels is equivalent to operating a 24-h air-conditioner (AC) or dehumidifier, which is energy-consuming. As a large part of building expense, the operation time of ACs has been regularly proposed to be cut down because of the requirement of building sustainability. This leads to a trade-off between sustainable building performance and indoor mold hygiene. To balance this trade-off, more sustainable alternatives, such as those that target physical environments (e.g. nutrient and temperature level) or apply new surface coating technologies to inhibit mold growth, have been launched. Despite these initiatives, indoor mold contamination remains an unresolved issue, mainly because these alternative measures only exhibit limited effectiveness or require extra effort. This review aims to summarize the currently adopted mold control measures and discuss their limitations as well as the direction for the future development of sustainable mold control strategies. SIGNIFICANCE AND IMPACT OF THE STUDY: People spend most of their time indoors and hence the presence of indoor mold contamination can compromise the occupants' health. With the wake of climate change which is expected to see an increase in RH and temperature, tropical and subtropical areas are even more prone to mold contamination than they used to be. This study may help facilitate the development of sustainable and effective mold control strategies in the indoor environment.

Endotoxin clustering with allergens in house dust and asthma outcomes in a U.S. national study

BACKGROUND

Endotoxin is ubiquitous in the environment, but its clustering with indoor allergens is not well characterized. This study examined the clustering patterns of endotoxin with allergens in house dust and their association with asthma outcomes.

METHODS

We analyzed data from 6963 participants of the 2005-2006 National Health and Nutrition Examination Survey. House dust sampled from bedroom floor and bedding was evaluated for endotoxin and allergens from fungi, cockroach, dog, cat, mites, and rodents. Two-step cluster analysis and logistic regressions were performed to identify the clustering patterns and their associations with current asthma and wheeze in the past 12 months, adjusting for covariates.

RESULTS

Of the homes, 17.8% had low endotoxin and allergen levels in house dust (Cluster 1). High endotoxin level clustered with Alternaria and pet allergens in the homes of participants with a high socioeconomic status who own pets (Cluster 2) (48.9%). High endotoxin clustered with Aspergillus, dust mites, cockroach, and rodent allergens in the homes of participants with low socioeconomic status (Cluster 3) (33.3%). Compared to Cluster 1, Cluster 2 was associated with higher asthma prevalence (OR 1.42, 95% CI: 1.06-1.91) and wheeze (OR 1.32, 95% CI: 1.07-1.63). Cluster 3 was positively associated with wheeze only in participants sensitized to inhalant allergens (OR 1.42, 95% CI: 1.06-1.91) or exposed to tobacco smoke (OR 1.72, 95% CI: 1.15-2.60).

CONCLUSIONS

The clustering of endotoxin with allergens in dust from homes with pets or of people with low socioeconomic status is associated with asthma and wheeze.

Comorbidity of Airway Inflammatory Diseases in Chemical and Building-Related Intolerance

OBJECTIVES

This study investigated comorbidity in chemical intolerance (CI) and building- related intolerance (BRI) with (i) chronic sinusitis, chronic obstructive pulmonary disease, allergic and nonallergic asthma and allergic rhinitis, and (ii) airway inflammatory symptoms.

METHODS

Data from two population-based questionnaire surveys, the Västerbotten and Österbotten Environmental Health Studies, were used. The participants were categorized as CI or BRI and referents, and binary logistic regression analysis was applied.

RESULTS

Prevalence rates for the case groups were 7.2% to 40.0% for diseases and 24.3% to 68.9% for symptoms, whereas adjusted odds ratios (ORs) were 3.4 to 26.1 for diseases and 3.3 to 17.0 for symptoms, all being significantly higher than unity. Prevalence rates and ORs were in general higher in BRI than in CI.

CONCLUSION

Inflammatory airway diseases and symptoms are associated with CI and BRI, which encourages further research regarding underlying mechanisms and treatments.

Analysis of the Occurrence of Thermal Bridges in Several Variants of Connections of the Wall and the Ground Floor in Construction Technology with the Use of a Hemp-lime Composite

This article analyses the connection of the two types of floors on the ground (floors on joists and self-supporting floors), with the external wall made of a hemp–lime composite for the occurrence of thermal bridges. Several factors that may affect the heat transfer in the junction were taken into account: the level of the floor on the ground, the wall thickness, the thermal conductivity of the composite, and the location of the timber frame construction. The technology of using hemp and lime is relatively new, and there is a lack of such analyses in the literature. The two-dimensional (2D) heat-transfer in the described construction joints was analyzed based on the finite-element method with the use of the THERM 7.4 software. The results were presented as averaged and linear thermal transmittance coefficients dependent on the above mentioned factors. The possibility of surface condensation was also checked. The differences in the values of the thermal transmittance of the junction between the two variants of ground floors reached around 0.13%–1.67% and the values of linear thermal transmittance factor reached approximately 2.43%–10.13%. The junctions with the highest floor level showed a decrease in the thermal transmittance value by about 3.00%–5.77% and in the linear thermal transmittance, by about 21.98%–53.83%, compared to the junctions with the lowest floor level. Calculations showed that almost all analyzed junctions are free from surface condensation causing mould growth, because the minimum temperature factors f_0.25 were higher than 0.78 (except for junctions with the lowered floor levels). The junction with a floor on the timber joists showed better thermal parameters than the junction with a self-supporting floor in each of the analyzed variants. By increasing the level of floor insulation, it is possible to limit the thermal bridges and improve the thermal properties of the junction.

Household dampness-related exposures in relation to childhood asthma and rhinitis in China: A multicentre observational study

During 2010-2012, we conducted an observational study on household environment and health outcomes among 40,010 preschool children from seven cities of China. Here we examined associations of six dampness-related indicators (visible mold spots, visible damp stains, damp clothing and/or bedding, water damage, condensation on windowpane, moldy odor) in the current residence and three dampness-related indicators (visible mold spots, condensation on windowpane, moldy odor) in the early residence with childhood asthma and rhinitis. In the multi-level logistic regression analyses, visible mold spots and visible damp stains in the current residence were significantly associated with the increased odds of doctor-diagnosed asthma and allergic rhinitis during lifetime-ever (adjusted odd ratios (AORs) range: 1.18-1.35). All dampness-related indicators were significantly associated with increased odds of wheeze and rhinitis during lifetime-ever and in the past 12 months (AORs range: 1.16-2.64). The cumulative numbers of damp indicators had positively dose-response relationships with the increased odds of the studied diseases. These associations for wheeze and rhinitis were similar between northern children and southern children. Similar results were found in the sensitive analyses among children without a family history of allergies and among children without asthma and allergic rhinitis. For 3-6 years-old children in mainland of China in 2011, we speculated that about 90,000 (2.02%) children with asthma and about 59,000 (1.09%) children with allergic rhinitis could be attributable to exposing to visible mold spots in the current residence. Our results suggested that early and lifetime exposures to household dampness indicators are risk factors for childhood asthma and rhinitis.

A Healthy, Energy-Efficient and Comfortable Indoor Environment, a Review

Design strategies for sustainable buildings, that improve building performance and avoid extensive resource utilization, should also promote healthy indoor environments. The following paper contains a review of the couplings between (1) building design, (2) indoor environmental quality and (3) occupant behavior. The paper focuses on defining the limits of adaptation on the three aforementioned levels to ensure the energy efficiency of the whole system and healthy environments. The adaptation limits are described for measurable physical parameters and the relevant responsible human sensory systems, evaluating thermal comfort, visual comfort, indoor air quality and acoustical quality. The goal is to describe the interactions between the three levels where none is a passive participant, but rather an active agent of a wider human-built environment system. The conclusions are drawn in regard to the comfort of the occupant. The study reviews more than 300 sources, ranging from journals, books, conference proceedings, and reports complemented by a review of standards and directives.

Modern life makes children allergic. A cross-sectional study: associations of home environment and lifestyles with asthma and allergy among children in Tianjin region, China

PURPOSE

In the past 60 years, the prevalences of asthma and allergy among children have increased around the world. Neither genetic nor outdoor environmental factors can explain this increase.

METHODS

We performed a cross-sectional study of 7366 children in Tianjin, China, on associations of home environment and lifestyles with asthma and allergy.

RESULTS

The prevalences of diagnosed asthma, rhinitis and eczema among 0- to 8-year-old children in the Tianjin area were 4%, 9% and 39%. Home environment and lifestyle, together with infections, were strong risk factors. For asthma and allergy, the population attributable fraction (PAF) due to modern floors and wall coverings (i.e., laminated wooden floors and painted walls compared to tile floors and lime-coated walls) was 22%. Window condensation in winter and air conditioner use in summer, both of which are proxies for less ventilation, accounted for 7-17% of rhinitis and eczema. Cesarean delivery accounted for 10% of eczema symptoms. We developed a modern life index from appropriate home characteristics and lifestyle and food consumption habits and found it to have a clear dose-response relationship with asthma and allergy in Tianjin children.

CONCLUSIONS

The results indicate that a "modern" home environment together with a modern lifestyle is associated with increased prevalences of asthma and allergies among children. Appropriate indoor environmental interventions and education of children's caregivers are important in the management of childhood asthma and allergy.

Online Questionnaire as a Tool to Assess Symptoms and Perceived Indoor Air Quality in a School Environment

School environments are a complex entirety where various different exposure factors are related that contribute to the indoor air quality (IAQ) and may affect occupants’ health and well-being. Indoor air questionnaires are useful for collecting information about the occupants’ experiences and perceptions of the indoor air and for evaluating the results of the measures taken. A common way to implement health questionnaires is to ask the respondents to describe symptoms at certain time points, such as weeks or months. The aim of our study was to develop a short and easy online questionnaire to assess symptoms and perceived IAQ. We also aimed to test the usability of the questionnaire in school buildings and assess the differences between the online measurement data (CO2, T, and RH) and the IAQ complaints and symptoms reported by the pupils. A total of 105 teachers and 1268 pupils in 36 classrooms at six schools answered the questionnaires over a two-week period. The participants completed the questionnaire always after the lesson in the studied classroom. We received 719 answers from the teachers and 6322 answers from the pupils. The results demonstrated that the teachers reported more IAQ problems and symptoms than the pupils did. Differences between classrooms were observed in both the IAQ problem and reference schools. The most common significant differences (p-value > 0.05) between the classrooms were among humidity, too cold air, and stuffy air, and among symptoms, dry/sore throat, tiredness, headache, and skin symptoms. Maximum values of CO2 measurements and the highest prevalence of stuffy air were relatively consistent. The testing process demonstrated that such a questionnaire was suitable for adults and children aged at least 12 years. The results of our study suggest that a quick and easy online questionnaire that is completed within a short period may be useful for gathering valuable knowledge about perceived IAQ. It could be used in combination with other indoor environment investigations to produce detailed results and restorative measures.

Microbial growth in building material samples and occupants' health in severely moisture-damaged homes

There is no commonly approved approach to detect and quantify the health-relevant microbial exposure in moisture-damaged buildings. In 39 single-family homes with severe moisture damage, we studied whether concentrations of viable microbes in building material samples are associated with health among 71 adults and 68 children, and assessed with symptoms questionnaires, exhaled NO, and peak expiratory flow (PEF) variability. Symptoms were grouped into three scores: upper respiratory symptoms, lower respiratory symptoms, and general symptoms. The homes were divided into three groups based on viable counts of fungi, actinomycetes, and total bacteria cultivated from building material samples. Highest group of actinomycete counts was associated with more general symptoms, worse perceived health, and higher daily PEF variability (aOR 12.51; 1.10-141.90 as compared to the lowest group) among adults, and with an increase in lower respiratory symptoms in children, but the confidence intervals were wide. We observed significant associations of fungal counts and total microbial score with worse perceived health in adults. No associations with exhaled NO were observed.

Mold and Human Health: a Reality Check

There are possibly millions of mold species on earth. The vast majority of these mold spores live in harmony with humans, rarely causing disease. The rare species that does cause disease does so by triggering allergies or asthma, or may be involved in hypersensitivity diseases such as allergic bronchopulmonary aspergillosis or allergic fungal sinusitis. Other hypersensitivity diseases include those related to occupational or domiciliary exposures to certain mold species, as in the case of Pigeon Breeder's disease, Farmer's lung, or humidifier fever. The final proven category of fungal diseases is through infection, as in the case of onchomycosis or coccidiomycosis. These diseases can be treated using anti-fungal agents. Molds and fungi can also be particularly important in infections that occur in immunocompromised patients. Systemic candidiasis does not occur unless the individual is immunodeficient. Previous reports of "toxic mold syndrome" or "toxic black mold" have been shown to be no more than media hype and mass hysteria, partly stemming from the misinterpreted concept of the "sick building syndrome." There is no scientific evidence that exposure to visible black mold in apartments and buildings can lead to the vague and subjective symptoms of memory loss, inability to focus, fatigue, and headaches that were reported by people who erroneously believed that they were suffering from "mycotoxicosis." Similarly, a causal relationship between cases of infant pulmonary hemorrhage and exposure to "black mold" has never been proven. Finally, there is no evidence of a link between autoimmune disease and mold exposure.

Housing conditions and birth outcomes: The National Child Development Study

BACKGROUND

Despite their importance to respiratory and other health outcomes, housing conditions have been little-studied with respect to perinatal outcomes.

METHODS

1927 participants in the British National Child Development Study reported on housing conditions and pregnancy outcomes, including presence/severity of mold/dampness; type of heating; and whether remodeling of various sorts had been conducted. Crowding, based on the number of people in the residence and the number of rooms, was also considered. Outcomes assessed were low birthweight (< 2500g), preterm birth (< 37 weeks), and small-for-gestational-age (< 10th percentile for gestational age). Multiple logistic regression with adjustment for maternal, sociodemographic, and housing factors was conducted.

RESULTS

Women who reported serious problems with mold were more likely to give birth to a low birthweight (adjusted OR 1.98, 95% CI 1.13-3.47) or small-for-gestational-age (2.06, 1.25-3.38) baby; no consistent associations were seen with preterm birth. Crowding was associated only with small-for-gestational-age (1.73, 1.11-2.76).

CONCLUSIONS

Exposure to mold or dampness, and housing conditions generally, is a potentially important but under-investigated aspect of women's lives during pregnancy. Future studies should more thoroughly investigate housing characteristics and their relationship with birth outcomes.

Building-integrated agriculture: A first assessment of aerobiological air quality in rooftop greenhouses (i-RTGs)

Building-integrated rooftop greenhouse (i-RTG) agriculture has intensified in recent years, due to the growing interest in the development of new agricultural spaces and in the promotion of food self-sufficiency in urban areas. This paper provides a first assessment of the indoor dynamics of bioaerosols in an i-RTG, with the aim of evaluating biological air quality in a tomato greenhouse near Barcelona. It evaluates the greenhouse workers' exposure to airborne pollen and fungal spores in order to prevent allergy problems associated with occupational tasks. Moreover, it evaluates whether the quality of the hot air accumulated in the i-RTG is adequate for recirculation to heat the building. Daily airborne pollen and fungal spore concentrations were measured simultaneously in the indoor and outdoor environments during the warm season. A total of 4,924pollengrains/m³ were observed in the i-RTG, with a peak of 334pollengrains/m³day, and a total of 295,038 fungal spores were observed, reaching a maximum concentration of 26,185spores/m³day. In general, the results showed that the most important source of pollen grains and fungal spores observed indoors was the outdoor environment. However, Solanaceae pollen and several fungal spore taxa, such as the allergenic Aspergillus/Penicillium, largely originated inside the greenhouses or were able to colonize the indoor environment under favourable growing conditions. Specific meteorological conditions and agricultural management tasks are related to the highest observed indoor concentrations of pollen grains and fungal spores. Therefore, preventive measures have been suggested in order to reduce or control the levels of bioaerosols indoors (to install a system to interrupt the recirculation of air to the building during critical periods or to implement appropriate air filters in ventilation air ducts). This first evaluation could help in making decisions to prevent the development of fungal diseases, specifically those due to Oidium and Torula.

Indoor air pollutants, ventilation rate determinants and potential control strategies in Chinese dwellings: A literature review

After nearly twenty years of rapid modernization and urbanization in China, huge achievements have transformed the daily lives of the Chinese people. However, unprecedented environmental consequences in both indoor and outdoor environments have accompanied this progress and have triggered public awareness and demands for improved living standards, especially in residential environments. Indoor pollution data measured for >7000 dwellings (approximately 1/3 were newly decorated and were tested for volatile organic compound (VOC) measurements, while the rest were tested for particles, phthalates and other semi-volatile organic compounds (SVOCs), moisture/mold, inorganic gases and radon) in China within the last ten years were reviewed, summarized and compared with indoor concentration recommendations based on sensory or health end-points. Ubiquitous pollutants that exceed the concentration recommendations, including particulate matter, formaldehyde, benzene and other VOCs, moisture/mold, inorganic gases and radon, were found, indicating a common indoor air quality (IAQ) issue in Chinese dwellings. With very little prevention, oral, inhalation and dermal exposure to those pollutants at unhealthy concentration levels is almost inevitable. CO₂, VOCs, humidity and radon can serve as ventilation determinants, each with different ventilation demands and strategies, at typical occupant densities in China; and particle reduction should be a prerequisite for determining ventilation requirements. Two directional ventilation modes would have profound impacts on improving IAQ for Chinese residences are: 1) natural (or window) ventilation with an air cleaner and 2) mechanical ventilation with an air filtration unit, these two modes were reviewed and compared for their applicability and advantages and disadvantages for reducing human exposure to indoor air pollutants. In general, mode 2 can more reliably ensure good IAQ for occupants; while mode 1 is more applicable due to its low cost and low energy consumption. However, besides a roadmap, substantial efforts are still needed to develop affordable, applicable and general ventilation solutions to improve the IAQ of residential buildings in China.

Linking childhood allergic asthma phenotypes with endotype through integrated systems biology: current evidence and research needs

Asthma and other complex diseases results from a complex web of interactions involving inflammation, immunity, cell cycle, apoptosis, and metabolic perturbations across multiple organ systems. The extent to which various degrees of the age at onset, symptom severity, and the natural progression of the disease reflect multiple disease subtypes, influenced by unique process of development remains unknown. One of the most critical challenges to our understanding stems from incomplete understanding of the mechanisms. Within this review, we focus on the phenotypes of childhood allergic asthma as the basis to better understand the endotype for quantitative define subtypes of asthma. We highlight some of the known mechanistic pathways associated with the key hallmark events before the asthma onset. In particular, we examine how the recent advent of multiaxial -omics technologies and systems biology could help to clarify our current understanding of the pathway. We review how a large volume of molecular, genomic data generated by multiaxial technologies could be digested to identify cogent pathophysiologic molecular networks. We highlight some recent successes in application of these technologies within the context of other disease conditions for therapeutic interventions. We conclude by summarizing the research needs for the predictive value of preclinical biomarkers.

School attendance and daily respiratory symptoms in children: influence of moisture damage

We investigated the effect of weekends and school holidays on the daily frequency and severity of respiratory and other symptoms among children attending schools with (index) or without (reference) moisture damage in Spain, the Netherlands, and Finland. Throughout 1 year, parents of 419 children with a respiratory condition attending index (n=15) or reference (n=10) primary schools completed three symptom diaries. We assessed associations between lower respiratory tract, upper respiratory tract or allergy, and other symptom scores and school day, weekend, or summer holiday using mixed regression models stratified by country and moisture damage. We evaluated interactions between moisture damage and type of day. We combined country-specific estimates (incidence rate ratios [IRRs] and 95% confidence interval [CI]) in meta-analyses. Symptom scores were lower during weekends and holiday. Lower respiratory tract symptoms were statistically significantly less common during holiday with strongest effect in index schools (IRR=0.7; CI=0.6-0.8). Reporting of other symptoms was more reduced during holiday in index (IRR=0.6; CI=0.4-0.9) than in reference (IRR=0.95; CI=0.8-1.2) schools (interaction P<.01). In conclusion, symptoms were less frequent and/or severe during summer holiday and weekends. This pattern was stronger among children attending moisture-damaged schools, suggesting potential improvement in moisture damage-related symptoms during school breaks.

An Evolutionary-Based Framework for Analyzing Mold and Dampness-Associated Symptoms in DMHS

Among potential environmental harmful factors, fungi deserve special consideration. Their intrinsic ability to actively germinate or infect host tissues might determine a prominent trigger in host defense mechanisms. With the appearance of fungi in evolutionary history, other organisms had to evolve strategies to recognize and cope with them. Existing controversies around dampness and mold hypersensitivity syndrome (DMHS) can be due to the great variability of clinical symptoms but also of possible eliciting factors associated with mold and dampness. An hypothesis is presented, where an evolutionary analysis of the different response patterns seen in DMHS is able to explain the existing variability of disease patterns. Classical interpretation of immune responses and symptoms are addressed within the field of pathophysiology. The presented evolutionary analysis seeks for the ultimate causes of the vast array of symptoms in DMHS. Symptoms can be interpreted as induced by direct (toxic) actions of spores, mycotoxins, or other fungal metabolites, or on the other side by the host-initiated response, which aims to counterbalance and fight off potentially deleterious effects or fungal infection. Further, individual susceptibility of immune reactions can confer an exaggerated response, and magnified symptoms are then explained in terms of immunopathology. IgE-mediated allergy fits well in this scenario, where individuals with an atopic predisposition suffer from an exaggerated response to mold exposure, but studies addressing why such responses have evolved and if they could be advantageous are scarce. Human history is plenty of plagues and diseases connected with mold exposure, which could explain vulnerability to mold allergy. Likewise, multiorgan symptoms in DMHS are analyzed for its possible adaptive role not only in the defense of an active infection, but also as evolved mechanisms for avoidance of potentially harmful environments in an evolutionary past or present setting.

Volatile organic compounds of possible microbial origin and their risks on childhood asthma and allergies within damp homes

BACKGROUND

Risk of indoor exposure to volatile organic compounds of purported microbial origin on childhood symptoms of wheezing, rhinitis, and/or eczema, and doctor-diagnosed asthma, rhinitis, and eczema, respectively, remain unclear.

OBJECTIVE

To test hypotheses that total sum of 28 microbial volatile organic compounds (Σ26 MVOCs): 1) poses independent risk on doctor-diagnosed asthma, rhinitis, and eczema, respectively, as well as multiple symptom presentation with a minimum of the two of the above conditions (i.e. case); 2) is associated with significant interaction with absolute humidity (AH) on additive scale.

METHODS

In a case-control investigation, 198 cases and 202 controls were examined during November 2001 - March 2002 period through home indoor air sampling, air quality inspection, and health outcome ascertainment.

RESULTS

Not only the Σ28 MVOCs but also the global MVOC index were significantly higher within the homes of the cases with a high AH, compared to the controls with a low AH (all Ps<0.001). Only the cases, but not the controls, were associated with a dose-dependent increase in the exposure variables of interest (Σ28 MVOCs) per quartile increase in AH (P<0.0001 for the cases; P=0.780 for the controls). Only among the children who live in a high AH homes, a natural log (ln)-unit of Σ 28 MVOCs was associated with 2.5-times greater odds of the case status (95% CI, 1.0-6.2; P=0.046), compared to 0.7-times the odds (95% CI, 0.4-1.0; P=0.074) of the same outcome among the low AH homes. Specifically, joint exposure to a high MVOCs and high AH was associated with 2.6-times greater odds of the doctor-diagnosed asthma status (95% CI, 0.7-8.91; P=0.137).

CONCLUSION

Joint occurrence of high Σ28 MVOCs and AH was associated with a significant increase in the case status and asthma risks in an additive scale.

Respiratory Diseases in University Students Associated with Exposure to Residential Dampness or Mold

University students are frequently exposed to residential dampness or mold (i.e., visible mold, mold odor, dampness, or water leaks), a well-known contributor to asthma, allergic rhinitis, and respiratory infections. This study aims to: (a) describe the prevalence of these respiratory diseases among university students; and (b) examine the independent contribution of residential dampness or mold to these diseases. An online survey was conducted in March 2014 among the 26,676 students registered at the Université de Sherbrooke (Quebec, Canada). Validated questions and scores were used to assess self-reported respiratory diseases (i.e., asthma-like symptoms, allergic rhinitis, and respiratory infections), residential dampness or mold, and covariates (e.g., student characteristics). Using logistic regressions, the crude and adjusted odd ratios between residential dampness or mold and self-reported respiratory diseases were examined. Results from the participating students (n = 2097; response rate: 8.1%) showed high prevalence of allergic rhinitis (32.6%; 95% CI: 30.6–34.7), asthma-like symptoms (24.0%; 95% CI: 22.1–25.8) and respiratory infections (19.4%; 95% CI: 17.7–21.2). After adjustment, exposure to residential dampness or mold was associated with allergic rhinitis (OR: 1.25; 95% CI: 1.01–1.55) and asthma-like symptoms (OR: 1.70; 95% CI: 1.37–2.11), but not with respiratory infections (OR: 1.07; 95% CI: 0.85–1.36). Among symptomatic students, this exposure was also associated with uncontrolled and burdensome respiratory symptoms (p < 0.01). University students report a high prevalence of allergic rhinitis, asthma-like symptoms and respiratory infections. A common indoor hazard, residential dampness or mold, may play a role in increasing atopic respiratory diseases and their suboptimal control in young adults. These results emphasize the importance for public health organizations to tackle poor housing conditions, especially amongst university students who should be considered “at-risk”.

Fungal compositions and diversities on indoor surfaces with visible mold growths in residential buildings in the Seoul Capital Area of South Korea

Indoor visible mold growths are known to be associated with allergies and respiratory illnesses. However, a question remains of their compositions and diversities. Using swab sampling and high-throughput DNA sequencing, this study analyzed taxonomic compositions and diversities of fungi on indoor surfaces laden with visible mold growths in residential apartments in South Korea. The sequencing results showed low species diversities with Shannon indices ranging from 0.14 to 2.29 (mean = 1.11). Several allergy-related genera were detected on the same surface, where the most abundant Cladosporium with a mean relative abundance of 41% co-occurred with less abundant Aspergillus (0.094%), Rhodotorula (6.3%), Cryptococcus (3.7%), Alternaria (4.1%), and Crivellia (17%). β diversity analyses showed significant differences in the fungal communities between enclosed balconies and other indoor areas (P < 0.05, ANOSIM), emphasizing a need to sample at multiple indoor locations when assessments are made for indoor visible mold growths. High-throughput sequencing is powerful in characterizing compositions and diversities of fungal communities. Future studies should examine the relationships between taxonomic compositions and diversities of indoor visible molds and health outcomes of allergies and respiratory illnesses in residential buildings.

Valuing the Economic Costs of Allergic Rhinitis, Acute Bronchitis, and Asthma from Exposure to Indoor Dampness and Mold in the US

Two foundational methods for estimating the total economic burden of disease are cost of illness (COI) and willingness to pay (WTP). WTP measures the full cost to society, but WTP estimates are difficult to compute and rarely available. COI methods are more often used but less likely to reflect full costs. This paper attempts to estimate the full economic cost (2014$) of illnesses resulting from exposure to dampness and mold using COI methods and WTP where the data is available. A limited sensitivity analysis of alternative methods and assumptions demonstrates a wide potential range of estimates. In the final estimates, the total annual cost to society attributable to dampness and mold is estimated to be $3.7 (2.3-4.7) billion for allergic rhinitis, $1.9 (1.1-2.3) billion for acute bronchitis, $15.1 (9.4-20.6) billion for asthma morbidity, and $1.7 (0.4-4.5) billion for asthma mortality. The corresponding costs from all causes, not limited to dampness and mold, using the same approach would be $24.8 billion for allergic rhinitis, $13.5 billion for acute bronchitis, $94.5 billion for asthma morbidity, and $10.8 billion for asthma mortality.

Effect of indoor air quality of day care centers in children with different predisposition for asthma

BACKGROUND

Scarce information is available about the relationships between indoor air quality (IAQ) at day care centers (DCC), the estimated predisposition for asthma, and the actual wheezing susceptibility.

METHODS

In the Phase II of ENVIRH study, 19 DCC were recruited after cluster analysis. Children were evaluated firstly using the ISAAC questionnaire and later by a follow-up questionnaire about recent wheezing. A positive asthma predictive index (API) was considered as predisposition for asthma. Every DCC was audited for IAQ and monitored for chemical and biologic contaminants.

RESULTS

We included 1191 children, with a median age of 43 (P25 -P75 : 25-58) months. Considering the overall sample, in the first questionnaire, associations were found between CO2 concentration (increments of 200 ppm) and diagnosis of asthma (OR: 1.10; 95% CI: 1.00-1.20). Each increment of 100 μg/m(3) of total volatile organic compounds (TVOC) and 1 μg of Der p1/g of dust were associated with wheezing in the previous 12 months (OR: 1.06; 95% CI: 1.01-1.11 and OR: 1.06; 95% CI: 0.99-1.12, respectively). In the follow-up questionnaire, TVOC were again associated with wheezing (OR: 1.05; 95% CI: 1.00-1.11). Children exposed to fungal concentration above the 75th percentile had also higher odds of wheezing at follow-up. TVOC were associated with wheezing in children with either negative or positive API.

CONCLUSIONS

IAQ in DCC seems to be associated with wheezing, in children with and without predisposition for asthma.

Observational scores of dampness and mold associated with measurements of microbial agents and moisture in three public schools

We examined associations between observational dampness scores and measurements of microbial agents and moisture in three public schools. A dampness score was created for each room from 4-point-scale scores (0-3) of water damage, water stains, visible mold, moldy odor, and wetness for each of 8 room components (ceiling, walls, windows, floor, ventilation, furniture, floor trench, and pipes), when present. We created mixed microbial exposure indices (MMEIs) for each of 121 rooms by summing decile ranks of 8 analytes (total culturable fungi; total, Gram-negative, and Gram-positive culturable bacteria; ergosterol; (1→3)-β-D-glucan; muramic acid; and endotoxin) in floor dust. We found significant (P ≤ 0.01) linear associations between the dampness score and culturable bacteria (total, Gram-positive, and Gram-negative) and the MMEIs. Rooms with dampness scores greater than 0.25 (median) had significantly (P < 0.05) higher levels of most microbial agents, MMEIs, and relative moisture content than those with lower scores (≤0.25). Rooms with reported recent water leaks had significantly (P < 0.05) higher dampness scores than those with historical or no reported water leaks. This study suggests that observational assessment of dampness and mold using a standardized form may be valuable for identifying and documenting water damage and associated microbial contamination.

Poor housing conditions in association with child health in a disadvantaged immigrant population: a cross-sectional study in Rosengård, Malmö, Sweden

OBJECTIVES

To describe the home environment in terms of housing conditions and their association with child health in a disadvantaged immigrant population.

DESIGN

A cross-sectional observational study.

SETTING

Enrolment took place during 2010-2011 in Rosengård, Malmö, Sweden.

PARTICIPANTS

Children aged 0-13 years in 2 study neighbourhoods were recruited from local health records and from schools. 359 children participated, with a participation rate of 40%. Data on health, lifestyle and apartment characteristics from questionnaire-led interviews with the mothers of the children were obtained together with data from home inspections carried out by trained health communicators.

OUTCOME MEASURES

Logistic regression analysis was used to estimate ORs for various health outcomes, adjusted for demographic information and lifestyle factors.

RESULTS

The housing conditions were very poor, especially in one of the study neighbourhoods where 67% of the apartments had been sanitised of cockroaches, 27% were infested with cockroaches and 40% had a visible mould. The association between housing conditions and health was mostly inconclusive, but there were statistically significant associations between current asthma and dampness (OR=4.1, 95% CI 1.7 to 9.9), between asthma medication and dampness (OR=2.8, 95% CI 1.2 to 6.4), and between mould and headache (OR=4.2, 95% CI 1.2 to 14.8). The presence of cockroaches was associated with emergency care visits, with colds, with headache and with difficulty falling asleep, and worse general health was associated with mould and presence of cockroaches.

CONCLUSIONS

The associations between dampness and asthma, and the association between mould and headache, are in line with current knowledge. The presence of cockroaches seemed to be associated with various outcomes, including those related to mental well-being, which is less described in the literature. The results of the present study are hypothesis generating and provide strong incentives for future studies in this study population.

Lifetime prevalence of childhood eczema and the effect of indoor environmental factors: Analysis in Hispanic and non-Hispanic white children

BACKGROUND

The prevalence of eczema varies markedly across the globe. It is unclear whether the geographic variation is due to race and/or ethnic differences, environmental exposures, or genetic factors.

OBJECTIVE

We investigated the effects of ethnicity and environmental exposures on eczema in Hispanic white and non-Hispanic white children who participated in the Southern California Children's Health Study.

METHODS

We performed a cross-sectional study with sociodemographic predictors and environmental exposures among Hispanic white and non-Hispanic white children ages 4-8 years enrolled in the Children's Health Study, 2002-2003.

RESULTS

Eczema prevalence differed by ethnicity: Hispanic whites showed lower prevalence (13.8%) compared with non-Hispanic whites (20.2%), and adjustment for sociodemographic factors did not account for the ethnic difference (odds ratio [OR] 0.79 [95% confidence interval {CI}, 0.65-0.95]). Parental history of allergic disease had a larger effect in Hispanic whites than in non-Hispanic whites (p for interaction = 0.005). High maternal education level (OR 1.46 [95% CI, 1.14-1.87]), parental history of allergic disease (OR 2.21 [95% CI, 1.78-2.76]), and maternal smoking during pregnancy (OR 1.44 [95% CI, 1.06-1.95]) increased the risk of eczema. Indoor environmental factors (e.g., mold, water damage, humidifier use) increased the risk of eczema in non-Hispanic whites independent of a parental history of allergic disease, but, in Hispanic whites, increased risks were observed, primarily in children without a parental history of allergic disease.

CONCLUSION

Hispanic white children in southern California had a lower prevalence of eczema than non-Hispanic whites, and this ethnic difference was not accounted for by sociodemographic differences. The effects of a parental history of allergic disease and indoor environmental exposures on eczema varied by ethnicity, which indicated that the etiology of eczema may differ in Hispanic whites and in non-Hispanic whites.

Characterization of particulate matter concentrations and bioaerosol on each floor at a building in Seoul, Korea

Particulate matter (PM) in buildings are mostly sourced from the transport of outdoor particles through a heating, ventilation, and air conditioning (HVAC) system and generation of particle within the building itself. We investigated the concentrations and characteristic of indoor and outdoor particles and airborne bacteria concentrations across four floors of a building located in a high-traffic area. In all the floors we studied (first, second, fifth, and eighth), the average concentrations of particles less than 10 μm (PM10) in winter for were higher than those in summer. On average, a seasonal variation in the PM10 level was found for the first, fifth, and eighth floors, such that higher values occurred in the winter season, compared to the summer season. In addition, in winter, the indoor concentrations of PM10 on the first, fifth, and eighth floors were higher than those of the outdoor PM10. The maximum level of airborne bacteria concentration was found in a fifth floor office, which held a private academy school consisting of many students. Results indicated that the airborne bacteria remained at their highest concentration throughout the weekday period and varied by students' activity. The correlation coefficient (R (2)) and slope of linear approximation for the concentrations of particulate matter were used to evaluate the relationship between the indoor and outdoor particulate matter. These results can be used to predict both the indoor particle levels and the risk of personal exposure to airborne bacteria.

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.

Indoor Air Problems and Hoarseness in Children

OBJECTIVES

A well-functioning voice is becoming increasingly important because voice-demanding professions are increasing. The largest proportion of voice disorders is caused by factors in the environment. Moisture damage is common and can initiate microbial growth and/or diffusion of chemicals from building materials. Indoor air problems due to moisture damage are associated with a number of health symptoms, for example, rhinitis, cough, and asthma symptoms. The purpose of this study was to investigate if children attending a day care center, preschool, or school with indoor air problems due to moisture damage were hoarse more often than the children in a control group.

METHODS

Information was collected through electronic and paper questionnaires from the parents of 6- to 9-year-old children (n = 1857) attending 57 different day care centers, preschools, or schools with or without indoor air problems due to moisture damage.

RESULTS

The results showed a significant correlation between the degree of indoor air problem due to moisture damage and the frequency of hoarseness. Significant predictors for the child being hoarse every week or more often were dry cough, phlegm cough, and nasal congestion.

CONCLUSIONS

The results indicate that these symptoms and exposure to indoor air problems due to moisture damage should be included in voice anamnesis. Furthermore, efforts should be made to remediate indoor air problems due to moisture damage and to treat health symptoms.

Fungal burden in waste industry: an occupational risk to be solved

High loads of fungi have been reported in different types of waste management plants. This study intends to assess fungal contamination in one waste-sorting plant before and after cleaning procedures in order to analyze their effectiveness. Air samples of 50 L were collected through an impaction method, while surface samples, taken at the same time, were collected by the swabbing method and subject to further macro- and microscopic observations. In addition, we collected air samples of 250 L using the impinger Coriolis μ air sampler (Bertin Technologies) at 300 L/min airflow rate in order to perform real-time quantitative PCR (qPCR) amplification of genes from specific fungal species, namely Aspergillus fumigatus and Aspergillus flavus complexes, as well as Stachybotrys chartarum species. Fungal quantification in the air ranged from 180 to 5,280 CFU m(-3) before cleaning and from 220 to 2,460 CFU m(-3) after cleaning procedures. Surfaces presented results that ranged from 29×10(4) to 109×10(4) CFU m(-2) before cleaning and from 11×10(4) to 89×10(4) CFU m(-2) after cleaning. Statistically significant differences regarding fungal load were not detected between before and after cleaning procedures. Toxigenic strains from A. flavus complex and S. chartarum were not detected by qPCR. Conversely, the A. fumigatus species was successfully detected by qPCR and interestingly it was amplified in two samples where no detection by conventional methods was observed. Overall, these results reveal the inefficacy of the cleaning procedures and that it is important to determine fungal burden in order to carry out risk assessment.

Remediating buildings damaged by dampness and mould for preventing or reducing respiratory tract symptoms, infections and asthma

BACKGROUND

Dampness and mould in buildings have been associated with adverse respiratory symptoms, asthma and respiratory infections of inhabitants. Moisture damage is a very common problem in private houses, workplaces and public buildings such as schools.

OBJECTIVES

To determine the effectiveness of repairing buildings damaged by dampness and mould in order to reduce or prevent respiratory tract symptoms, infections and symptoms of asthma.

SEARCH METHODS

We searched CENTRAL (2014, Issue 10), MEDLINE (1951 to November week 1, 2014), EMBASE (1974 to November 2014), CINAHL (1982 to November 2014), Science Citation Index (1973 to November 2014), Biosis Previews (1989 to June 2011), NIOSHTIC (1930 to March 2014) and CISDOC (1974 to March 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs), cluster-RCTs (cRCTs), interrupted time series studies and controlled before-after (CBA) studies of the effects of remediating dampness and mould in a building on respiratory symptoms, infections and asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed the risk of bias in the included studies.

MAIN RESULTS

We included 12 studies (8028 participants): two RCTs (294 participants), one cRCT (4407 participants) and nine CBA studies (3327 participants). The interventions varied from thorough renovation to cleaning only.Repairing houses decreased asthma-related symptoms in adults (among others, wheezing (odds ratio (OR) 0.64; 95% confidence interval (CI) 0.55 to 0.75) and respiratory infections (among others, rhinitis (OR 0.57; 95% CI 0.49 to 0.66), two studies, moderate-quality evidence). For children, we did not find a difference between repaired houses and receiving information only, in the number of asthma days or emergency department visits because of asthma (one study, moderate-quality evidence).One CBA study showed very low-quality evidence that after repairing a mould-damaged office building, asthma-related and other respiratory symptoms decreased. In another CBA study, there was no difference in symptoms between full or partial repair of houses.For children in schools, the evidence of an effect of mould remediation on respiratory symptoms was inconsistent and out of many symptom measures only respiratory infections might have decreased after the intervention. For staff in schools, there was very low-quality evidence that asthma-related and other respiratory symptoms in mould-damaged schools were similar to those of staff in non-damaged schools, both before and after intervention.

AUTHORS' CONCLUSIONS

We found moderate to very low-quality evidence that repairing mould-damaged houses and offices decreases asthma-related symptoms and respiratory infections compared to no intervention in adults. There is very low-quality evidence that although repairing schools did not significantly change respiratory symptoms in staff, pupils' visits to physicians due to a common cold were less frequent after remediation of the school. Better research, preferably with a cRCT design and with more validated outcome measures, is needed.

The peptide toxin amylosin of Bacillus amyloliquefaciens from moisture-damaged buildings is immunotoxic, induces potassium efflux from mammalian cells, and has antimicrobial activity

Amylosin, a heat-stable channel-forming non-ribosomally synthesized peptide toxin produced by strains of Bacillus amyloliquefaciens isolated from moisture-damaged buildings, is shown in this paper to have immunotoxic and cytotoxic effects on human cells as well as antagonistic effects on microbes. Human macrophages exposed to 50 ng of amylosin ml(-1) secreted high levels of cytokines interleukin-1β (IL-1β) and IL-18 within 2 h, indicating activation of the NLRP3 inflammasome, an integral part of the innate immune system. At the same exposure level, expression of IL-1β and IL-18 mRNA increased. Amylosin caused dose-dependent potassium ion efflux from all tested mammalian cells (human monocytes and keratinocytes and porcine sperm cells) at 1 to 2 μM exposure. Amylosin also inhibited the motility of porcine sperm cells and depolarized the mitochondria of human keratinocytes. Amylosin may thus trigger the activation of the NLRP3 inflammasome and subsequently cytokine release by causing potassium efflux from exposed cells. The results of this study indicate that exposure to amylosin activates the innate immune system, which could offer an explanation for the inflammatory symptoms experienced by occupants of moisture-damaged buildings. In addition, the amylosin-producing B. amyloliquefaciens inhibited the growth of both prokaryotic and eukaryotic indoor microbes, and purified amylosin also had an antimicrobial effect. These antimicrobial effects could make amylosin producers dominant and therefore significant causal agents of health problems in some moisture-damaged sites.

Microbiological characterization of 3193 French dwellings of Elfe cohort children

Although exposure to indoor microorganisms in early life has already been associated with respiratory illness or allergy protection, only a few studies have performed standardized samplings and specific microbial analysis. Moreover, most do not target the different groups of microorganisms involved in respiratory diseases (fungi, bacteria, dust mites). In our study, ten specific qPCR targets (6 fungal species, 1 family and 2 genera of bacteria, 1 house dust mite) were used to analyze the microorganism composition of electrostatic dust fall collector (EDC) from 3193 dwellings of the Elfe French cohort study. Multivariate analyses allowed us to show that the microbial composition of dwellings, assessed with simultaneous analysis of 10 microorganisms, can be characterized by four entities: three bacteria, house dust mite Dermatophagoïdes pteronyssinus, fungi Alternaria alternata, and five other molds. Some dwellings' intrinsic characteristics (occupational ratio, type of dwelling and presence of pets) clearly influence microorganism distribution, and six different profiles of dwellings, characterized by their composition in microorganisms, have been described across France. The use of these clusters seems promising in the evaluation of allergic risk. Allergic respiratory diseases will develop in the near future in some children of the Elfe cohort and will indicate to what extent our approach can be predictive of respiratory disease.

Home dampness, childhood asthma, hay fever, and airway symptoms in Shanghai, China: associations, dose-response relationships, and lifestyle's influences

Numerous studies of associations between dampness and respiratory diseases have been conducted, but their implications remain inconclusive. In this study of 13,335 parent-reported questionnaires (response rate: 85.3%), we analyzed associations between home dampness and asthma and related symptoms in 4- to 6-year-old children in a cross-sectional study of Shanghai. Indicators of home dampness were strongly and significantly associated with dry cough, wheeze, and rhinitis symptoms. In the current residence, children with visible mold spots (VMS) exposure had 32% higher risk of asthma (adjusted OR, 95% CI: 1.32, 1.07-1.64); damp clothing and/or bedding (frequently) was strongly associated with dry cough (1.78, 1.37-2.30); condensation on windows was strongly associated with hay fever (1.60, 1.27-2.01). In the early-life residence, VMS or damp stains (frequently) were strongly associated with dry cough (2.20, 1.55-3.11) and rhinitis ever (1.57, 1.11-2.21). Associations between dampness and diseases among children with or without family history of atopy were similar. The total number of dampness indicators had strong dose-response relationships with investigated health outcomes. Actions, including opening windows of the child's room at night and cleaning the child's room frequently, could potentially mitigate 25% of home VMS, thereby preventing more than 1.5% of attributable risk of the studied symptoms.

Rhinitis, asthma and respiratory infections among adults in relation to the home environment in multi-family buildings in Sweden

Risk factors for rhinitis, asthma and respiratory infections in the home environment were studied by a questionnaire survey. Totally 5775 occupants (≥ 18 years old) from a stratified random sample of multi-family buildings in Sweden participated (46%). 51.0% had rhinitis in the last 3 months (current rhinitis); 11.5% doctor diagnosed asthma; 46.4% respiratory infections in the last 3 months and 11.9% antibiotic medication for respiratory infections in the last 12 months. Associations between home environment and health were analyzed by multiple logistic regression, controlling for gender, age and smoking and mutual adjustment. Buildings constructed during 1960-1975 were risk factors for day time breathlessness (OR = 1.53, 95%CI 1.03-2.29). And those constructed during 1976-1985 had more current rhinitis (OR = 1.43, 95%CI 1.12-1.84) and respiratory infections (OR = 1.46, 95%CI 1.21-1.78). Cities with higher population density had more current rhinitis (p = 0.008) and respiratory infections (p<0.001). Rented apartments had more current rhinitis (OR = 1.23, 95%CI 1.07-1.40), wheeze (OR = 1.20, 95%CI 1.02-1.41), day time breathlessness (OR = 1.31, 95%CI 1.04-1.66) and respiratory infections (OR = 1.13, 95%CI 1.01-1.26). Living in colder parts of the country was a risk factor for wheeze (p = 0.03) and night time breathlessness (p = 0.002). Building dampness was a risk factor for wheeze (OR = 1.42, 95%CI 1.08-1.86) and day time breathlessness (OR = 1.57, 95%CI 1.09-2.27). Building dampness was a risk factor for health among those below 66 years old. Odor at home was a risk factor for doctor diagnosed asthma (OR = 1.49, 95%CI 1.08-2.06) and current asthma (OR = 1.52, 95%CI 1.03-2.24). Environmental tobacco smoke (ETS) was a risk factor for current asthma (OR = 1.53, 95%CI 1.09-2.16). Window panel condensation was a risk factor for antibiotic medication for respiratory infections (OR = 1.41, 95%CI 1.10-1.82). In conclusion, rhinitis, asthma and respiratory infections were related to a number of factors in the home environment. Certain building years (1961-1985), building dampness, window panel condensation and odor in the dwelling may be risk factors.

Proteomic changes of alveolar lining fluid in illnesses associated with exposure to inhaled non-infectious microbial particles

Background

Hyperresponsiveness to inhaled non-infectious microbial particles (NIMPs) has been associated with illnesses in the airways. Hypersensitivity pneumonitis (HP) is considered to be the prototype for these NIMPs-related diseases; however, there is no consensus on the definitions or diagnostic criteria for HP and the spectrum of related illnesses.

Methods and Findings

In order to identify the possible diagnostic markers for illnesses associated with NIMPs in alveolar lining fluid, we performed a proteomic analysis using a two-dimensional difference gel electrophoresis on bronchoalveolar lavage (BAL) fluid from patients with exposure to NIMPs in the context of damp building-related illness (DBRI) or conditions on the borderline to acute HP, designated here as agricultural type of microbial exposure (AME). Samples from patients with HP and sarcoidosis (SARC) were included for reference. Results were compared to results of healthy subjects (CTR). Western blot was used for validation of potential marker proteins from BAL fluid and plasma. Protein expression patterns suggest a close similarity between AME and HP, while DBRI was similar to CTR. However, in DBRI the levels of the inflammation associated molecules galectin-3 and alpha-1-antitrypsin were increased. A novel finding emerging from this study was the increases of semenogelin levels in BAL fluid from patients with AME, HP and SARC. Histone 4 levels were increased in AME, HP and SARC. Elevated plasma levels of histone 2B were detected in HP and SARC, suggesting it to be a potential blood indicator for inflammatory diseases of the lungs.

Conclusions

In this study, the proteomic changes in bronchoalveolar lavage of DBRI patients were distinct from other NIMP exposure associated lung diseases, while changes in AME overlapped those observed for HP patient samples. Some of the proteins identified in this study, semenogelin and histone 4, could function as diagnostic markers for differential diagnosis between DBRI and HP-like conditions.

Biochemical and immunological analysis of mould skin prick test solution: current status of standardization

BACKGROUND

Sensitization prevalence to moulds reached from less than 10% in the general population to more than 25% in atopic and/or asthmatic subjects. To diagnose IgE-mediated mould sensitization, skin prick test (SPT) and specific IgE (sIgE) measurement are recommended. However, concordance of SPT and sIgE results is often less than 50% and standardization of the extracts is required to achieve reliable test results.

OBJECTIVE

The aim of our study was to analyse mould SPT solutions (SPTs) with respect to quantity and quality of protein, antigen and human IgE-binding content as a prerequisite for further in vivo studies.

METHODS

Commercial SPTs of Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum and Penicillium chrysogenum from six manufacturers as well as two in-house extracts from Aspergillus versicolor were investigated. Protein-, antigen- and IgE-binding contents were quantified by Bradford assay, sandwich ELISA and IgE-ImmunoCAP-inhibition tests. Protein composition and IgE and IgG binding were analysed by SDS-PAGE and immunoblotting, respectively.

RESULTS

Median protein concentrations were similar in all mould SPT extracts (90-110 μg/mL). In contrast, antigen contents and IgE-binding capacity showed a high variability with median antigen values from 4 to 118 μg/mL and IgE inhibition results between 30 to 95%. Whereas almost all SPTs of A. alternata and A. versicolor showed complete sIgE inhibition with mean values > 80%, only three extracts for A. fumigatus, two extracts for C. herbarum and none of the tested extracts for P. chrysogenum exceeded 50% sIgE reduction. Quantitative amounts of protein, antigenic and IgE-binding structures were not comparable with the quality of the corresponding protein or immunoblot pattern, with the exception of A. alternata SPTs.

CONCLUSIONS AND CLINICAL RELEVANCE

Commercially available mould SPT extracts showed high variability raising the question of comparability and reliability of SPT results. Possible consequences for diagnostic test outcome will be investigated in the next step.

Ensuring functionality of a nearly zero-energy building with procurement methods

Purpose

– The purpose of this paper is to show the results of the task given by a major research program concerning low-energy building and indoor environment. The task was to develop contracting document model layouts to be used in zero-energy building (ZEB) and nearly zero-energy building (nZEB) construction projects.

Design/methodology/approach

– A workshop method was chosen for gathering information and developing the layouts.

Findings

– In the debate in the workshop three main topics arose: the selection of project delivery system, the use of performance controller for the heating, ventilation and air-conditioning (HVAC) systems and making innovation possible by making the call for bids as loose as possible.

Research limitations/implications

– The use of performance controller could be investigated more, and more accurate information and knowledge about the best practices on nZEB construction can be captured as the industry moves in that direction and more projects will appear.

Originality/value

– The goals of the research program were met and also the main issues of nZEB construction contracting were documented, which can be utilized by the whole industry of house building.

Rhinitis symptoms and asthma among parents of preschool children in relation to the home environment in Chongqing, China

Risk factors for rhinitis and asthma in the home environment were studied by a questionnaire survey. Parents of 4530 1-8 year old children (one parent per child) from randomly selected kindergartens in Chongqing, China participated. 70.4% were females; 47.1% had rhinitis symptoms in the last three months (current rhinitis, CR); 1.6% reported a history of allergic asthma (AA); 2.7% reported a history of allergic rhinitis (AR); 16.4% were current smokers; 50.8% males and 2.4% females were current smokers. Stuffy odor, unpleasant odor, tobacco smoke odor and dry air were associated with CR (adjustment for gender, current smoking and other perceptions of odor or humidity). Associations between home environment and CR, AR, and AA were studied by multiple logistic regression analyses, adjusting for gender, current smoking and other significant home factors. Living near a main road or highway was a risk factor for both CR (OR(95%CI): 1.31(1.13,1.52)) and AR (OR(95%CI): 2.44(1.48,4.03)). Other risk factors for CR included living in rural areas (OR(95%CI): 1.43(1.10,1.85)), new furniture (OR(95%CI): 1.28(1.11,1.49)), water damage (OR(95%CI): 1.68(1.29,2.18)), cockroaches (OR(95%CI): 1.46(1.23,1.73)), and keeping pets (OR(95%CI): 1.24(1.04,1.49)). Other risk factors for AR included redecoration (OR(95%CI): 2.14(1.34,3.41)), mold spots (OR(95%CI): 2.23(1.06,4.68)), window pane condensation (OR(95%CI): 2.04(1.28,3.26)). Water damage was the only home factor associated with AA (2.56(1.34,4.86)). Frequently put bedding to sunshine was protective for CR (OR(95%CI): 0.79(0.68,0.92); cleaning every day was protective for AR (OR(95%CI): 0.40(0.22,0.71)). In conclusion, parents' CR and AR were related to a number of factors of the home environment.

Residential culturable fungi, (1-3, 1-6)-β-d-glucan, and ergosterol concentrations in dust are not associated with asthma, rhinitis, or eczema diagnoses in children

Qualitative reporting of home indoor moisture problems predicts respiratory diseases. However, causal agents underlying such qualitative markers remain unknown. In the homes of 198 multiple allergic case children and 202 controls in Sweden, we cultivated culturable fungi by directly plating dust, and quantified (1-3, 1-6)-β-D-glucan and ergosterol in dust samples from the child's bedroom. We examined the relationship between these fungal agents and degree of parent or inspector-reported home indoor dampness, and microbiological laboratory's mold index. We also compared the concentrations of these agents between multiple allergic cases and healthy controls, as well as IgE-sensitization among cases. The concentrations of culturable fungal agents were comparable between houses with parent and inspector-reported mold issues and those without. There were no differences in concentrations of the individual or the total summed culturable fungi, (1-3, 1-6)-β-D-glucan, and ergosterol between the controls and the multiple allergic case children, or individual diagnosis of asthma, rhinitis, or eczema. Culturable fungi, (1-3, 1-6)-β-D-glucan, and ergosterol in dust were not associated with qualitative markers of indoor dampness or mold or indoor humidity. Furthermore, these agents in dust samples were not associated with any health outcomes in the children.