共查询到20条相似文献,搜索用时 0 毫秒
1.
Rhinosinusitis and mold as risk factors for asthma symptoms in occupants of a water-damaged building
Abstract Mold exposure in damp buildings is associated with both nasal symptoms and asthma development, but the progression of building-related (BR) rhinosinusitis symptoms to asthma is unstudied. We examined the risk of developing BR-asthma symptoms in relation to prior BR-rhinosinusitis symptoms and microbial exposure among occupants of a damp building. We conducted four cross-sectional health and environmental surveys among occupants of a 20-story water-damaged office building. We defined BR-rhinosinusitis symptom (N?=?131) and comparison (N?=?361) groups from participants' first questionnaire responses. We compared the odds for the development of BR-asthma symptoms between these two groups over the subsequent surveys, using logistic regression models adjusted for demographics, smoking, building tenure, and first-survey exposures to fungi, endotoxin, and ergosterol. The BR-rhinosinusitis symptom group had higher odds for developing BR-asthma symptoms [odds ratio (OR)?=?2.2; 95% confidence interval (CI)?=?1.3-3.6] in any subsequent survey compared to those without BR-rhinosinusitis symptoms. The BR-rhinosinusitis symptom group with higher fungal exposure within the building had an OR of 7.4 (95% CI?=?2.8-19.9) for developing BR-asthma symptoms, compared to the lower fungal exposure group without BR-rhinosinusitis symptoms. Our findings suggest that rhinosinusitis associated with occupancy of water-damaged buildings may be a sentinel for increased risk for asthma onset in such buildings. PRACTICAL IMPLICATIONS: Exposure to mold is associated with the development of asthma in damp building occupants, and rhinitis is known to be a risk factor for asthma. However, there is little information about the degree of risk for the progression of rhinosinusitis to asthma owing to mold exposures in damp buildings. Our study of damp building occupants demonstrates that building-related (BR) rhinosinusitis symptoms were a risk factor for the development of BR asthma symptoms and that exposure to mold (fungi) or other dampness-related agents augments risk for the development of BR asthma symptoms among those with BR rhinosinusitis symptoms. Our findings suggest that occurrence of BR upper respiratory illness in water-damaged buildings may presage future endemic asthma. 相似文献
2.
3.
The inhibitory effects of silver nanoparticles, silver ions, and silver chloride colloids on microbial growth 总被引:6,自引:0,他引:6
Emerging nanomaterials are of great concern to wastewater treatment utilities and the environment. The inhibitory effects of silver nanoparticles (Ag NPs) and other important Ag species on microbial growth were evaluated using extant respirometry and an automatic microtiter fluorescence assay. Using autotrophic nitrifying organisms from a well-controlled continuously operated bioreactor, Ag NPs (average size=14+/-6 nm), Ag(+) ions (AgNO(3)), and AgCl colloids (average size=0.25 microm), all at 1mg/L Ag, inhibited respiration by 86+/-3%, 42+/-7%, and 46+/-4%, respectively. Based on a prolonged microtiter assay, at about 0.5mg/L Ag, the inhibitions on the growth of Escherichia coli PHL628-gfp by Ag NPs, Ag(+) ions, and AgCl colloids were 55+/-8%, 100%, and 66+/-6%, respectively. Cell membrane integrity was not compromised under the treatment of test Ag species by using a LIVE/DEAD Baclight bacterial viability assay. However, electron micrographs demonstrated that Ag NPs attached to the microbial cells, probably causing cell wall pitting. The results suggest that nitrifying bacteria are especially susceptible to inhibition by Ag NPs, and the accumulation of Ag NPs could have detrimental effects on the microorganisms in wastewater treatment. 相似文献
4.
Impact of UV disinfection on microbially available phosphorus,organic carbon,and microbial growth in drinking water 总被引:2,自引:0,他引:2
Lehtola MJ Miettinen IT Vartiainen T Rantakokko P Hirvonen A Martikainen PJ 《Water research》2003,37(5):1064-1070
UV irradiation at a wavelength of 253.7 nm (UV(254)) is commonly used for drinking water disinfection. UV radiation is known to convert organically combined phosphorus to orthophosphate and to degrade natural organic matter. We studied if UV disinfection increases the amount of microbially available forms of organic carbon and phosphorus in drinking waters with different characteristics, and if these changes in water chemical quality could enhance the microbial growth in drinking water. The UV(254) dose (15-50 mWs/cm(2)) used in waterworks reduced the concentration of assimilable organic carbon and the sum of the molecular size fractions. The release of microbially available phosphorus needed higher doses (204 mWs/cm(2)) of UV(254) radiation. Of bacteria in drinking water, 90% were inactivated with UV(254)-irradiation doses below 50 mWs/cm(2). A high dose (501 mWs/cm(2)) of UV(254) radiation inhibited the microbial growth in water. 相似文献
5.
6.
Recent literature suggests two mechanisms through which the start‐up of new firms contributes to economic development: the growth of start‐ups and competition among incumbent firms induced by the start‐ups. While existing studies derive the competition effect indirectly, this paper deploys a direct measure, called market mobility, to approximate the induced competition effect. The empirical results are consistent with the idea that both effects are important in explaining the long‐term economic impact of start‐ups. First, the most successful start‐ups grow to become high‐growth firms, and second, the entry of new firms stimulates incumbent firms to perform better. 相似文献
7.
Moderating effects of the geometry of reservoirs on the relation between urban land use and water quality 总被引:7,自引:0,他引:7
Soon-Jin Hwang Sang-Woo Lee Ju-Youn Son Geun-Ae Park Seong-Joon Kim 《Landscape and urban planning》2007,82(4):175-183
Edges mediate the material flux between adjacent systems. This mediating effect of edges is strongly tied to the complexity of the adjacent shapes. Land use within a watershed has a direct impact on the water quality of adjacent aquatic systems. Hydrological processes carry material produced by land-use activities into aquatic ecosystems through the edges of the ecosystem. Therefore, the geometry of aquatic ecosystems theoretically affects the relationship between land use and water quality. This study investigates whether the shape complexity of reservoirs moderates the direct impact of land use on the water quality of adjacent reservoirs. A moderation model was adopted to measure the shape effects, and 153 reservoirs were randomly sampled with a consideration of reservoir size (surface area), geographic location, and data availability. With a focus on urban land use, we used GIS to measure land-use types within a 1 km buffer of reservoir boundaries. The shape complexity of sampled reservoirs was measured using fractal dimensions. Land uses and shape complexity were then regressed to measure water quality parameters such as chemical oxygen demand (COD), biological oxygen demand (BOD), total nitrogen (TN) and total phosphorus (TP). Correlation analysis revealed that the shapes of reservoirs are likely to be simple where urban land use dominates the areas close to reservoirs. Use of the standard regression model indicated that the increasing shape complexity of reservoirs significantly reduces the concentration of BOD, COD, and TP within reservoir water. Moderation models for BOD, COD, TN, and TP suggest that shape complexity can considerably relieve the negative impacts on water quality of urban land use in areas adjacent to reservoirs. The results of this study highlight the need to focus on shoreline management in order to mitigate the adverse impacts of land use on lakes and reservoirs. 相似文献
8.
S. Saari J. Mensah‐Attipoe T. Reponen A. M. Veijalainen A. Salmela P. Pasanen J. Keskinen 《Indoor air》2015,25(6):653-661
Real‐time bioaerosol monitoring is possible with fluorescence based instruments. This study provides information on major factors that can affect the fluorescence properties of airborne fungal spores. Two fluorescence‐based bioaerosol detectors, BioScout, and ultraviolet aerodynamic particle sizer (UVAPS), were used to study fluorescent particle fractions (FPFs) of released spores of three fungal species (Aspergillus versicolor, Cladosporium cladosporioides, and Penicillium brevicompactum). Two culture media (agar and gypsum board), three ages of the culture (one week, one month, and four months), and three aerosolization air velocities (5, 15, and 27 m/s) were tested. The results showed that the FPF values for spores released from gypsum were typically lower than for those released from agar indicating that poor nutrient substrate produces spores with lower amounts of fluorescent compounds. The results also showed higher FPF values with lower air velocities in aerosolization. This indicates that easily released fully developed spores have more fluorescent compounds compared to forcibly extracted non‐matured spores. The FPFs typically were lower with older samples. The FPF results between the two instruments were similar, except with four‐month‐old samples. The results can be utilized in field measurements of fungal spores to estimate actual concentrations and compare different instruments with fluorescence‐based devices as well as in instrument calibration and testing in laboratory conditions. 相似文献
9.
The impact of heat and water stress conditions on the growth of the biofuel plant Jatropha curcas 总被引:1,自引:0,他引:1
《The International journal of environmental studies》2012,69(2):273-288
Pot experiments were carried out to evaluate the effects of drought and salinity stresses and mulch amendment on Jatropha in sand dune soil under three conditions: glasshouse, shade house and open area. Plants were irrigated with freshwater and diluted seawater adjusted to two levels of electrical conductivity- 3 and 6 dS m-1. The results showed that experimental conditions remarkably affected the evapo-transpiration rate, soil moisture, salts accumulation and plant biomass production. Low temperature (23°C) conditions exhibited highest plant growth and soil moisture and lowest salts deposition. Plants showed no symptoms of heat stress in the glasshouse. The shade house and the open area profoundly reduced plant biomass and water content in the soil. Compared to the control, the mulch amended treatments had sufficient water for plant growth even in the high temperature of the open area. High salt content was found in salinity treated pots but the salinity level did not reduce Jatropha growth. Salt accumulated in the salinity treated pots helped retain more water, reduced the temperature and provided nutrients to the plants, with results which were almost similar to those from the mulch effect. The temperature conditions of the shade house and the open area (max>40°C) caused substantial water loss and induced death of plants. Jatropha is a succulent and drought tolerant plant and a close irrigation interval is not the best option for Jatropha growth. But, organic amendment is needed when there is a big loss of soil water due to heat stress condition. 相似文献
10.
11.
Distribution of dissolved cadmium between Chlorella stigmatophora and sea water medium—and possible effects of cadmium on the alga's growth—were investigated at cadmium concentrations between 1–10 mg 1−1. Results show considerable cadmium uptake by Chlorella stigmatophora along the growth curve. No effect of cadmium uptake on growth expressed by number of cells was recorded but a considerable decrease in chlorophyll content per cell was established. A mathematical expression was developed for the distribution of cadmium between Chlorella stigmatophora and sea water medium. 相似文献
12.
对比了东西方在文化及思维习惯上的主要区别,由此讨论了东西方宗教建筑、城镇与都市的规划营造、建筑空间本身的构成处理等方面的差异. 相似文献
13.
Chenqiu Du Baizhan Li Wei Yu Jiao Cai Lexiang Wang Xinyi Li Yinghui Yao Bicheng Li 《Indoor air》2021,31(2):541-556
Despite concerns about building dampness and children’ health, few studies have examined the effects of building energy efficiency standards. This study explored the connections between self-reported household dampness and children’ adverse health outcomes across buildings corresponding to construction periods (pre-2001, 2001-2010, post-2010). Significant differences of dampness-related indicators were found between buildings; the prevalence was remarkable in pre-2001 buildings. The prevalence of lifetime-ever doctor-diagnosed diseases for children was significantly associated with building dampness (adjust odd ratios > 1), but was not affected by construction periods. The hygrothermal performance for a typical residence was simulated, varying in U-values of envelopes and air change rates. The simulated performance improvement increased indoor temperatures in 2001-2010 and post-2010 buildings. The frequency with higher indoor relative humidity was higher in pre-2001 buildings, leading to the highest values for maximum mold index (Mmax) on wall surface, especially in winter. Compared to buildings in 2001-2010, increased insulation and lower air change rate led to a relatively higher relative humidity in post-2010 buildings, adversely increasing the Mmax values. The findings addressed the positive and negative role of building standard development, which help suggesting appropriate environmental and design solutions to trade-off energy savings and dampness/mold risk in residences. 相似文献
14.
在文献[1]采用的现场试验对桩与承台(基础)之间不同构造方式下的承台(基础)-桩-土相互作用进行的研究基础上,首先采用有限元数值分析模拟承台-单桩-土系统的相互作用,通过参数调整,使其能够模拟文献[1]进行的现场试验并给出较为接近的结果。在此基础上,采用数值仿真试验对多桩情况下桩顶与承台直接接触、复合地基及桩顶预留净空基础在竖向荷载作用下的工作性状进行了对比分析与研究,比较了相同荷载、桩长、桩距、承台厚度等情况下各种构造形式基础的受力特点。同时,通过改变桩长、桩距、预留净空大小等影响因素,进一步研究了桩长、桩距、预留净空对多桩桩顶预留净空基础的桩土荷载分担比例和沉降的影响。 相似文献
15.
16.
The effect of rock classes on the relation between uniaxial compressive strength and point load index 总被引:5,自引:0,他引:5
Uniaxial compressive strength and point load tests were carried out on 17 igneous, 16 metamorphic and 19 sedimentary rocks
and the values correlated with their I
s values. The influence of the different rock type was investigated using regression analysis and the derived equations were
statistically tested. Although the derived equation for all data is significant, the data points are scattered and the coefficient
of correlation is not strong. However, when the regression analysis was repeated for igneous, metamorphic and sedimentary
rocks respectively, the data were less scattered and stronger correlation coefficients were obtained.
相似文献
17.
This paper is to investigate the unique impact of simulation time-resolutions on energy matching between on-site micro-wind turbine and household electric demand. The focused indices are on-site electrical energy fraction (OEFe), on-site electrical energy matching (OEMe), and their errors (eOEF and eOEM). The methodology consists of parametric analyses with respect to time-resolution levels, averaging methods, demand profiles, turbine capacities, and wind conditions. Two averaging methods are used: ‘Speed Averaging’ and ‘Power Averaging’. With a coarser resolution, two averaging effects have been found. One is an overestimation effect by both the averaging methods, which are more likely to be encountered especially when a high-resolution generation curve frequently crosses intermittent long spikes of a demand curve. The other effect is an underestimation effect on OEFe simultaneously occurring with the Speed Averaging Method under the conditions of (1) a low wind speed and (2) a high unstable wind speed and a low turbine capacity. 相似文献
18.
Shaking table test and numerical simulation on vibration control effects of TMD with different mass ratios on a super high‐rise structure 下载免费PDF全文
Zheng Lu Hengrui Zhang Bin Zhao Xianjie Li 《The Structural Design of Tall and Special Buildings》2018,27(9)
In this paper, the influence of mass ratio on the vibration control effects of tuned mass damper (TMD) on a super high‐rise building has been investigated. A 1/45 scaled model of a super high‐rise building was constructed, and the TMD with the mass ratio of 0.01, 0.02, and 0.03, respectively, was suspended on the top. Shaking table test and the corresponding numerical simulation were carried out to make a further understanding of the damping mechanism. The structural performance with or without TMD was comparatively studied. The results show that larger mass ratio can improve the control effects under frequent earthquake, but the control effects increase little with the increase of mass ratio under rare earthquake due to structural damages, accompanied by stiffness degradation and nonlinear behavior of the main structure. In addition, some suggestions on the mass ratio selection are also proposed to generalize its applications. 相似文献
19.
Lars Collvin 《Water research》1984,18(2):139-144
Addition of copper to the ambient water of perch resulted in decreased daily maximum respiration rates (Rmax) and growth rates. The time-course of the effect in Rmax was characterized by: (1) an initial decrease over three additions; (2) a minimal “trough” lasting some 10–15 days; and (3) a phase of increasing Rmax. The variation in Rmax was due to copper concentration and exposure time. The decrease in growth rate was most dramatic initially and was correlated to copper concentration and perch weight. The subsequent increase in growth rate was constant and independent of copper concentration. The increase in Rmax and in growth rate was interpreted as acclimatization. Up to a given sublethal copper concentration acclimatization resulted in a return to the control level of Rmax but not of growth rate. 相似文献
20.
Bastian Heider 《Papers in Regional Science》2019,98(3):1443-1468
This paper uses the quasi-experimental setting of the 2004 EU enlargement, as well as town-level data along the affected German border, to estimate the effect of economic integration on border town population development. Using a difference-in-differences approach, we find that the accession has had a significant positive effect on the rate of population change after 2004. However, this does not offset the, generally, poorer population development of border towns compared to interior towns. Moreover, the integration effect appears to strongly depend on initial local conditions. No effects were found for Polish towns on the opposite side of the border. 相似文献