Dampness and mold in homes across China: Associations with rhinitis,ocular, throat and dermal symptoms,headache and fatigue among adults

We studied dampness and mold in China in relation to rhinitis, ocular, throat and dermal symptoms, headache and fatigue. A questionnaire study was performed in six cities including 36 541 randomized parents of young children. Seven self‐reported signs of dampness were evaluated. Multilevel logistic regression models were used to calculate odds ratios (ORs). Totally, 3.1% had weekly rhinitis, 2.8% eye, 4.1% throat and 4.8% skin symptoms, 3.0% headache and 13.9% fatigue. Overall, 6.3% of the homes had mold, 11.1% damp stains, 35.3% damp bed clothing, 12.8% water damage, 45.4% window pane condensation, 11.1% mold odor, and 37.5% humid air. All dampness signs were associated with symptoms (ORs from 1.2 to 4.6; P < 0.001), including rhinitis (ORs from 1.4 to 3.2; P < 0.001), and ORs increased by number of dampness signs. The strongest associations were for mold odor (ORs from 2.3 to 4.6) and humid air (ORs from 2.8 to 4.8). Associations were stronger among men and stronger in Beijing as compared to south China. In conclusion, dampness and mold are common in Chinese homes and associated with rhinitis and ocular, throat and dermal symptoms, headache and fatigue. Men can be more sensitive to dampness and health effects of dampness can be stronger in northern China.     

Higher measured moisture in California homes with qualitative evidence of dampness

Relationships between measured moisture and qualitative dampness indicators (mold odor, visible mold, visible water damage, or peeling paint) were evaluated using data collected from California homes in a prospective birth cohort study when the infants were 6 or 12 months of age (737 home visits). For repeated visits, agreement between observation of the presence/absence of each qualitative indicator at both visits was high (71–87%, P < 0.0001). Among individual indicators, musty odor and visible mold were most strongly correlated with elevated moisture readings. Measured moisture differed significantly between repeated visits in opposite seasons (P < 0.0001), and dampness increased with the number of indicators in a home. Linear mixed‐effect models showed that 10‐unit increases in maximum measured moisture were associated with the presence of 0.5 additional dampness indicators (P < 0.001). Bedroom (BR) walls were damper than living room (LR) walls in the same homes (P < 0.0001), although both average and maximum readings were positively correlated across room type (r = 0.75 and 0.67, respectively, both P < 0.0001). Exterior walls were significantly damper than interior walls (P < 0.0001 in both LRs and BRs), but no differences were observed between maximum wall readings and measurements at either window corners or sites of suspected dampness.     

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.     

Microbial secondary metabolites in homes in association with moisture damage and asthma

We aimed to characterize the presence of microbial secondary metabolites in homes and their association with moisture damage, mold, and asthma development. Living room floor dust was analyzed by LC‐MS/MS for 333 secondary metabolites from 93 homes of 1‐year‐old children. Moisture damage was present in 15 living rooms. At 6 years, 8 children had active and 15 lifetime doctor‐diagnosed asthma. The median number of different metabolites per house was 17 (range 8–29) and median sum load 65 (4–865) ng/m². Overall 42 different metabolites were detected. The number of metabolites present tended to be higher in homes with mold odor or moisture damage. The higher sum loads and number of metabolites with loads over 10 ng/m² were associated with lower prevalence of active asthma at 6 years (aOR 0.06 (95% CI <0.001–0.96) and 0.05 (<0.001–0.56), respectively). None of the individual metabolites, which presence tended (P < 0.2) to be increased by moisture damage or mold, were associated with increased risk of asthma. Microbial secondary metabolites are ubiquitously present in home floor dust. Moisture damage and mold tend to increase their numbers and amount. There was no evidence indicating that the secondary metabolites determined would explain the association between moisture damage, mold, and the development of asthma.     

Endotoxin and β(1→3)-Glucan in House Dust and the Relation with Home Characteristics: A Pilot Study in 25 German Houses

Abstract Residential microbial exposure has been suggested to be involved in the development of asthma. This paper describes bacterial endotoxin and mold β(1→3)-glucan levels in house dust and the relationship to selected home characteristics. Dust was sampled from mattresses and living room and bedroom floors of 25 houses in Germany. Endotoxin and β(1→3)-glucan levels ranged from 200-48,600 EU/g dust (100-32,900 EU/m² sampled surface) and 182-3,507 μg/g (157-3,652 μg/m²), respectively. Bio-contaminant levels were highest on living room floors and lowest in mattresses. Dust, endotoxin and β(1→3)-glucan levels were 2–3 times higher on living room floors of centrally heated houses built after 1970 compared to older individually heated houses. This was not found for mattresses and bedroom floors. No associations between biocontaminant levels and other selected home characteristics (temperature, relative humidity, damp spots and insulation of windows) were found. β(1→3)-glucan levels were associated with total culturable fungi (per m²) in house dust, as well as with the fungal genus Alternaria (per g dust and per m²). In conclusion endotoxin and β(1→3)-glucan were readily detectable in house dust and significantly associated with heating system and/or age of the home.     

Energy-efficient terrace houses in Sweden: Simulations and measurements

Reducing energy use in buildings is essential to decrease the environmental impact. Outside Gothenburg in Sweden, 20 terrace houses were built according to the passive house standard and completed in 2001. The goal was to show that it is possible to build passive houses in a Scandinavian climate with very low energy use and to normal costs. The houses are the result of a project including research, design, construction, monitoring and evaluation. The passive house standard means that the space heating peak load should not exceed 10 W/m² living area in order to use supply air heating. This requires low transmission and ventilation losses and the building envelope is therefore highly insulated and very airtight. A mechanical ventilation system with approximately 80% heat recovery is used. The electric resistance heating in the supply air is 900 W per living unit. Solar collectors on the roof provide 40% of the energy needed for the domestic hot water. The monitored delivered energy demand is 68 kWh/m² a. Energy simulations show that main differences between predicted and monitored energy performance concern the household electricity and the space heating demand. Total delivered energy is approximately 40% compared with normal standard in Sweden.     

Building leakage,infiltration, and energy performance analyses for Finnish detached houses

This study focuses on the relation between the airtightness of a building envelope, infiltration, and energy use of a typical modern Finnish detached house in the cold climate of Finland. The study is conducted with an empirically tested dynamic IDA-ICE simulation model of a detached house. The effect of several factors, such as Finnish climate and wind conditions, balance of ventilation system and leakage distribution, on infiltration was studied and a simple adapted model for the rough estimation of annual infiltration in Finnish detached houses was determined from the numerical simulation results. The energy impact of infiltration is also studied, taking into account the infiltration heat recovery effect. According to the results, infiltration causes about 15–30% of the energy use of space heating including ventilation in the typical Finnish detached house. The average infiltration rate and heat energy use increase almost linearly with the building leakage rate n₅₀. Finland can be roughly divided into two zones based on the average infiltration rate of detached houses, for which stack-induced infiltration is typically dominant, regardless of the climate zone. The infiltration heat recovery effect is minor in the studied detached house.     

Energy consumption and ventilation performance of a naturally ventilated ecological house in a cold climate

In this paper, the thermal and ventilation performance of an ecological house in Helsinki, Finland are presented. The single-family dwelling has a well-insulated, wooden frame construction with no plastic vapour retarder. The measured and simulated results show that the energy consumption of the house is low and that the outdoor ventilation rate is generally satisfactory based on the measured CO₂ concentrations. Extrapolating the measured ventilation data shows that, when the operable windows are closed, the ventilation rate is expected to be about 0.45 air-changes-per-hour (ach) in the winter and about 0.25 ach in the summer. The consumption of total primary energy and space heating energy were measured to be 30% less (162 kWh/(m² a)) and 36% less (76 kWh/(m² a)) than in typical Finnish houses, respectively. The paper also uses a numerical model to investigate the sensitivity of energy consumption to the insulation level, household electricity and domestic hot water consumption, window area, ventilation rate and heat recovery effectiveness.     

The potential and need for energy saving in standard family detached and semi-detached wooden houses in arctic Greenland

The paper gives an account of the potential and need for energy saving in standard family detached and semi-detached wooden houses in Greenland. It is based on studies of house construction compared with Building Regulation requirements and the spread of buildings over time. In the climatic conditions of Greenland, there is considerable potential for energy saving in houses due to their construction, shape and condition. To estimate the total potential for energy saving and thus reducing CO₂ emissions, we carried out a detailed investigation of three typical standard semi-detached family houses (type 18D). Temperature, relative humidity and air tightness were measured, and thermal bridges were determined from drawings, visual inspection, and by using a thermal camera. The findings show a current energy consumption of up to 383 kWh/(m² a) for heating, poor air tightness, a large number of thermal bridges, and high indoor temperatures. We demonstrate a potential for a reduction in CO₂ emission by a factor of 10. Finally, the paper describes a practical way of reducing thermal bridges significantly, increasing air tightness, upgrading insulation and adding mechanical ventilation to approximately half of the housing stock without changing the architectural expression or having to relocate the occupants during the renovation.     

The Modified Trombe Wall: A simple ventilation means and an efficient insulating material

This paper discusses the feasibility of reducing heat transferred into houses (insulation effect) and inducing natural ventilation by using a modified Trombe wall (MTW) under ambient conditions in Bangkok. It consists of a masonry wall, air gap and a gypsum wall which are common construction materials. It was found that the MTW with 2 m² of surface area, 14 cm air gap and dark in colour induced the highest natural ventilation rate, about 20–90 m³.h^?1. The light colour of the wall induced the lowest rate, but was still significant for the ventilation of houses. With such air flow rates, there is little potential to induce sufficient ventilation to achieve thermal comfort of the house, however, the proposed configuration of the MTW should be recommended for constructing new houses, mainly, because of its high insulation effect.     

Risk factors for mold in housing: a national survey

A national random telephone survey was undertaken to determine the prevalence of reported mold in New Zealand houses and the risk factors for it. A total of 613 households provided responses. Mold in one or more rooms was reported by 35.1% of respondents in the sample. House design and construction factors that were independently associated with reported mold in the multivariate analysis included: poorer house condition, older house age (>22 years), relative lack of sun exposure, and having no insulation (e.g. for poorer house condition: odds ratio=1.97, 95% CI=1.25, 3.11). Univariate analyses also showed increased risk associated with high locality rainfall, and living in the most northern part of the country. The number of residents was significantly associated with reported mold in the multivariate analysis as were various behaviors in the univariate analysis (i.e. frequency of baths, showering and clothes washing). The high prevalence of unflued gas heating (32.9%) found in this sample is of potential concern given the potential respiratory hazards. Although this survey has a number of limitations, it does suggest that there are a number of potentially modifiable risk factors for mold that could be reduced by a range of policy responses. PRACTICAL IMPLICATIONS: While further research is desirable, the available evidence associated with the health and other adverse impacts of both mold and dampness would favor additional policy responses by government. These could include changes to regulations around housing design including house position, access to sunlight, and level of insulation. The extension of low interest loans for insulation or subsidized installation can help to increase its level of use. Restrictions on the sales of unflued gas heaters could also be considered. A mass media campaign could also be used to inform the population of the readily modifiable risk factors for mold growth and dampness.     

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

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

The Influence of House Characteristics in a Canadian Community on Microbiological Contamination

Abstract Fifty-nine houses in the small Canadian community of Wallaceburg, 39 with high levels of biologically active contaminants and 20 with low levels, were subjected to detailed field inspections: testing to determine house-operating parameters; monitoring of indoor environmental conditions; and simulating to predict the condensation formation potential under winter conditions. It was found that low air leakage and natural ventilation were not associated with higher levels of mold growth, as measured by ergosterol concentrations and airborne viable particulates. Analyses showed that moisture sources in the houses were a more significant factor in mold levels and dust mite antigen levels than relative humidity. Mold areas visible during inspection were not a good predictor of ergosterol concentrations in dust, indicating that much of the mold growth was in hidden locations.     

Onset and remission of rhinitis among students in relation to the home and school environment—A cohort study from Northern China

Few prospective studies exist on indoor and outdoor air pollution in relation to adolescent rhinitis. We studied associations between onset and remission of rhinitis among junior high school students in relation to the home and school environment. A 2‐year questionnaire cohort study was performed among 1325 students (11‐15 years) in eight schools in Taiyuan, Northern China. Climate and air pollution were measured by direct reading instruments and passive samplers inside and outside the schools at baseline. Associations were calculated by multilevel logistic regression. Two‐year onset of rhinitis and weekly rhinitis were 26.7% and 13.1%, respectively. RH (P < 0.001), CO₂ (P < 0.01) and PM₁₀ (P < 0.01) in the classrooms, PM₁₀ (P < 0.01) and NO₂ (P < 0.05) outside the schools, and redecoration (OR = 2.25) and dampness/indoor mold at home (OR = 2.04) were associated with onset of weekly rhinitis. RH (P < 0.05) and CO₂ (P < 0.05) in the classroom and dampness/indoor mold (OR = 0.67) and environmental tobacco smoke (ETS) at home (OR = 0.63) reduced remission of rhinitis. In conclusion, dampness/mold and chemical emissions from new materials at home can increase onset of rhinitis and ETS and dampness/mold can reduce the remission. PM₁₀, RH, CO₂, and NO₂ at school can increase the onset, and RH and CO₂ can reduce the remission of rhinitis.     

冀北地区新农村住宅节能效益分析

建筑围护结构节能是建筑节能的重要组成部分。我国寒冷地区既有乡村住宅多属砖混结构,围护结构过于单薄、保温水平低,建筑运行陷入了高消耗、高排放、低舒适的恶性循环。根据所建立的节能住宅建筑能耗分析模型,利用能耗分析软件对中国辽宁省本溪市草砖房的全年采暖能耗进行了模拟计算。结果表明:节能住宅比普通住宅能耗低、保温效果好,冬季可节省采暖能耗70%左右,同时增加的投资在10年左右得到回收。     

Pilot study of the effects of ventilation and ventilation noise on sleep quality in the young and elderly

Three conditions were established to investigate the effects of ventilation and related ventilation noise on sleep quality: No mechanical ventilation/low noise (A); Mechanical ventilation /low noise (B); Mechanical ventilation/high noise (C). The interventions were achieved by idling a mechanical ventilation system or operating it in two different modes. Nine young people and nine older people were all exposed to each of the three conditions for a whole night's sleep, but data from only 15 subjects were analyzed as three young subjects apparently slept with open windows in condition A. Sleep quality was measured objectively with polysomnography (PSG), which monitored signals of electroencephalogram (EEG), bilateral electrooculogram (EOG), and chin electromyogram (EMG) continuously during the sleeping period. Saliva samples were collected before sleep at night and after waking in the morning, and the concentrations of cortisol and lysozyme in them were determined. Without mechanical ventilation, the indoor CO₂ level averaged about 1400 ppm during the night. Operating the mechanical ventilation decreased the indoor CO₂ to below 1000 ppm, which improved objectively measured sleep quality: wake time after sleep onset (WASO) decreased on average by 15 min (p < 0.05) and sleep efficiency (SE) increased on average by about 4% (p < 0.05). Increased ventilation noise level (50.8dB(A) vs. 34.7dB(A); 54.9dB(C) vs. 48dB(C)) did not significantly change SE or WASO but did change the duration of sleep stages: It decreased the duration of deep sleep by 11min (p < 0.05) and REM sleep by 17 min (p < 0.01) and increased the duration of light sleep by 17 min (p < 0.05). The ventilation noise significantly increased the concentration of lysozyme in the elderly (p < 0.05) although no significant effects on cortisol could be shown. These results confirm that a low ventilation rate has negative effects on sleep quality and that ventilation noise at or above 50dB(A) may disrupt sleep.     

Correlation of musty odor and 2-MIB in two drinking water treatment plants in South Taiwan

Possible odor groups and intensity, and seasonal effects were elucidated in two representative water treatment plants (WTPs), Feng-Shen and Gun-Shi, in southern Taiwan. The flavor profile analysis (FPA) was employed to determine the odor groups for the source water, while a chemical analysis, solid-phase microextraction (SPME) coupled with a gas chromatograph and mass spectrometric detector (GC/MSD), was used to concentrate and subsequently analyze the corresponding water samples. FPA results show that fishy and musty odors were the two major odor groups in the source water. Results of chemical analysis showed that 2-methyl-isoborneol (2-MIB) was present in the source water. The correlation between 2-MIB concentration and the FPA intensity of musty odor was compared with the dose-response curve generated in the laboratory by the FPA panelists. The experimental data from the two water treatment plants follow the calibration curve closely, indicating that the musty odor of the two source waters were most likely contributed from 2-MIB. In addition, there is good correlation between logarithmic 2-MIB concentration and water temperature, substantiating the importance of seasonal effect. Although approximately 40-50% of 2-MIB removal was found in the treatment trains for the two WTPs, only an approximately 0.3 FPA intensity scale of reduction was expected.     

Determining of heat balance design criteria for laying hen houses under continental climate conditions

This study focuses on the heat balance status of laying hen houses in regions with continental climate. The material consists of 45 laying hen houses from 27 commercial farms selected from the survey area where continental climate prevails. These laying hen houses differ from each other with respect to capacity, planning system and materials used in construction. First observations were conducted on the size and dimensions of laying hen houses as well as construction materials used, insulation, heat loss factors, ventilation capacity, ground space per hen and total size of laying hen house in order to assess the sufficiency of heat balance. Then, seven laying hen house models were developed. These models were developed by considering the present situation in operating laying hen houses, relevant literature, features of continental climate and suggestions made by firms manufacturing laying hen house construction materials in Turkey. These models give heat conduction coefficients that will prevent moisture concentration and ensure heat balance under continental climate conditions and suggest different sets of materials that can be used on walls and roofs. At the end of the study, under the condition of no moisture on surface of structural components and in areas where the indoor and outdoor temperatures are 25.3 °C and 20.2 °C, respectively, maximum total heat conduction coefficients are calculated to be between 1.38 and 1.73 Kcal/m² °C h. According to the features of area and housing, for providing heat balance, total heat conduction coefficients requirements are calculated to be between 0.62 and 2.08 Kcal/m² °C h for walls, 0.33 and 1.62 Kcal/m² °C h for roofs. In research area, minimum ventilation capacities are determined as 0.72 m³/h hen for carbon dioxide balance and, according to outdoor temperature, as 0.83–1.20 m³/h hen for water vapor balance. Heat loss factors are calculated to be between 0.10 and 0.15 Kcal/°C h hen. We believe that these suggestions will greatly facilitate the work of project engineers in the design of laying hen houses in regions and areas with continental climate.     

住宅的隔音设计

介绍了我国住宅建筑的隔音现状,提出了一些住宅设计中提高空气声隔音及楼板等撞击声隔音性能的途径及全社会共同努力的必要性,以尽可能多地提高隔声性能,为住户提供安静的居住环境。     

健康住宅声环境要求与隔声施工技术

对于健康住宅、生态住宅和3A住宅等高品质住宅,声环境符合设计要求是高要求住宅的必要条件。住宅的隔声设计与施工在住宅领域刚刚起步,住宅隔声施工关键技术措施研究尚存在技术瓶颈和应用难题。项目围绕健康住宅的声环境要求,结合高品质住宅试点项目,分类提出了楼板、墙体、窗户等的隔声施工技术方案和措施,并在工程实践中进行试点和检测。