scholarly journals Fungal populations in the bedroom dust of children in Havana, Cuba, and its relationship with environmental conditions

2021 ◽  
Author(s):  
Kenia C. Sánchez Espinosa ◽  
Teresa I. Rojas Flores ◽  
Sonia Rodríguez Davydenko ◽  
Silvia J. Venero Fernández ◽  
Michel Almaguer
Keyword(s):  
House Dust ◽  
Environmental Conditions ◽  
Fungal Diversity ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Cumulative Exposure ◽  
Malt Extract ◽  
Indoor Environments ◽  
Fungal Community Composition ◽  
Direct Microscopy

Abstract The study of the fungal community composition in house dust is useful to assess the cumulative exposure to fungi in indoor environments. The objective of this research was to characterize the fungal diversity of house dust and its association with the environmental conditions of bedrooms. For this, the dust was collected from 41 bedrooms of children between the ages of 8 and 9 with a family history of asthma, residents of Havana, Cuba. The fungal content of each sample was determined by two methods: plate culture with Malt Extract Agar and by direct microscopy. An ecological analysis was carried out from the fungal diversity detected. To describe the factors associated with the fungi detected, bivariate logistic regression was used. Through direct microscopy, between 10-2311 fragments of hyphae and spores corresponding mainly to Cladosporium, Coprinus, Curvularia, Aspergillus/Penicillium, Xylariaceae, and Periconia were identified. Through the culture, 0–208 CFU were quantified, where Aspergillus, Cladosporium, and Penicillium predominated. The culturability evidenced the differences between the quantification determined by both methods. A positive relationship was found between the type of cleaning of the furniture, the presence of trees in front of the bedroom, indoor relative humidity, indoor temperature, the presence of air conditioning by air conditioning and natural ventilation with specific spore types and genders. The use of two different identification methods allowed to detect a greater fungal diversity in the residences evaluated. Monitoring the exposure to these fungal allergens in childhood can help to prevent sensitization in the allergic child, the development of asthma and other respiratory diseases.

scholarly journals Testing the Toxicity of Stachybotrys chartarum in Indoor Environments—A Case Study

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1602
Author(s):  
Marlena Piontek ◽  
Katarzyna Łuszczyńska
Keyword(s):  
Health Concern ◽  
Major Constituent ◽  
Stachybotrys Chartarum ◽  
Malt Extract ◽  
Indoor Environments ◽  
Class Iii ◽  
Potential Health ◽  
Dugesia Tigrina ◽  
Ecotoxicological Tests ◽  
Interior Walls

Infestation of interior walls of buildings with fungal mould is a reason for health concern which is exacerbated in energy-efficient buildings that limit air circulation. Both mycological and mycotoxicological studies are needed to determine the potential health hazards to residents. In this paper, a rare case of the occurrence of Stachybotrys chartarum in an apartment building in the Lubuskie Province in Poland has been described. Isolated as the major constituent of a mixed mycobiota, its specific health relevance still needs to be carefully analyzed as its biochemical aptitude for the synthesis of mycotoxins may be expressed at different levels. Therefore, ecotoxicological tests were performed using two bioindicators: Dugesia tigrina Girard and Daphnia magna Straus. D. tigrina was used for the first time to examine the toxicity of S. chartarum. The ecotoxicological tests showed that the analyzed strain belonged to the third and fourth toxicity classes according to Liebmann’s classification. The strain of S. chartarum was moderately toxic on Potato Dextrose Agar (PDA) as a culture medium (toxicity class III), and slightly toxic on Malt Extract Agar (MEA) (toxicity class IV). Toxicity was additionally tested by instrumental analytical methods (LC-MS/MS). This method allowed for the identification of 13 metabolites (five metabolites reported for Stachybotrys and eight for unspecific metabolites). Spirocyclic drimanes were detected in considerable quantities (ng/g); a higher concentration was observed for stachybotryamide (109,000 on PDA and 62,500 on MEA) and lower for stachybotrylactam (27,100 on PDA and 46,300 on MEA). Both may explain the result observed through the bioindicators. Highly toxic compounds such as satratoxins were not found in the sample. This confirms the applicability of the two bioindicators, which also show mutual compatibility, as suitable tools to assess the toxicity of moulds.

scholarly journals Comparison of Downdraught and Up Draft Passive Air Conduction Systems (PACS) in a Winery Building

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 259
Author(s):  
Ádám László Katona ◽  
István Ervin Háber ◽  
István Kistelegdi
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
General Applicability ◽  
Change Rate ◽  
Air Change Rate ◽  
Simulation Based ◽  
Ventilation Performance ◽  
Air Conduction

A huge portion of energy consumption in buildings comes from heating, ventilation, and air conditioning. Numerous previous works assessed the potential of natural ventilation compared to mechanical ventilation and proved their justification on the field. Nevertheless, it is a major difficulty to collect enough information from the literature to make decisions between different natural ventilation solutions with a given situation and boundary conditions. The current study tests the passive air conduction system (PACS) variations in the design phase of a medium-sized new winery’s cellar and production hall in Villány, Hungary. A computational fluid dynamics simulation based comparative analysis enabled to determine the differences in updraft (UD) and downdraught (DD) PACS, whereby the latter was found to be more efficient. While the DD PACS performed an air change range of 1.02 h−1 to 5.98 h−1, the UD PACS delivered −0.25 h−1 to 12.82 h−1 air change rate. The ventilation performance of the DD version possessed lower amplitudes, but the distribution was more balanced under different wind incident angles, thus this version was chosen for construction. It could be concluded that the DD PACS provides a more general applicability for natural ventilation in moderate climates and in small to medium scale industry hall domains with one in- and one outlet.

66 Air conditioning AMD house dust mite

1985 ◽  
Vol 75 (1) ◽  
pp. 121 ◽  
Author(s):  
G CARPENTER ◽  
G WIN ◽  
R FURUMIZO ◽  
D MASSEY ◽  
A ORTIZ
Keyword(s):  
House Dust ◽  
House Dust Mite ◽  
Air Conditioning ◽  
Dust Mite

scholarly journals Performance Characteristics of Solid-Desiccant Evaporative Cooling Systems

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2574 ◽  
Author(s):  
Ramadas Narayanan ◽  
Edward Halawa ◽  
Sanjeev Jain
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Waste Heat ◽  
Numerical Study ◽  
Evaporative Cooling ◽  
Peak Load ◽  
Dew Point ◽  
Low Grade ◽  
Subtropical Climate ◽  
Cooling Systems

Air conditioning accounts for up to 50% of energy use in buildings. Increased air-conditioning-system installations not only increase total energy consumption but also raise peak load demand. Desiccant evaporative cooling systems use low-grade thermal energy, such as solar energy and waste heat, instead of electricity to provide thermal comfort. This system can potentially lead to significant energy saving, reduction in carbon emissions, and it has a low dew-point operation and large capacity range. Their light weight, simplicity of design, and close-to-atmospheric operation make them easy to maintain. This paper evaluates the applicability of this technology to the climatic conditions of Brisbane, Queensland, Australia, specifically for the residential sector. Given the subtropical climate of Brisbane, where humidity levels are not excessively high during cooling periods, the numerical study shows that such a system can be a potential alternative to conventional compression-based air-conditioning systems. Nevertheless, the installation of such a system in Brisbane’s climate zone requires careful design, proper selection of components, and a cheap heat source for regeneration. The paper also discusses the economy-cycle options for this system in such a climate and compares its effectiveness to natural ventilation.

scholarly journals Thermal comfort control via air conditioning system using fuzzy neural network feedback controller

2020 ◽  
Vol 19 (2) ◽  
pp. 586
Author(s):  
Somaye A. Mohamadi ◽  
Abdulraheem J. Ahmed
Keyword(s):  
Neural Network ◽  
Thermal Comfort ◽  
Environmental Conditions ◽  
Air Conditioning ◽  
Fuzzy Controller ◽  
Environmental Parameters ◽  
Thermal Conditions ◽  
Real Time Control ◽  
Air Conditioning System ◽  
Air Conditioning Systems

<span>Despite their complexity and uncertainty, air conditioning systems should provide the optimal thermal conditions in a building. These controller systems should be adaptable to changes in environmental parameters. In most air conditioning systems, today, there are On/Off controllers or PID in more advanced types, which, due to different environmental conditions, are not optimal and cannot provide the optimal environmental conditions. Controlling thermal comfort of an air conditioning system requires estimation of thermal comfort index. In this study, fuzzy controller was used to provide thermal comfort in an air conditioning system, and neural network was used to estimate thermal comfort in the feedback path of the controller. Fuzzy controller has a good response given the non-linear features of air conditioning systems. In addition, the neural network makes it possible to use thermal comfort feedback in a real-time control.</span>

House-dust mites and associated environmental conditions in Danish homes

Allergy ◽  
1993 ◽  
Vol 48 (2) ◽  
pp. 106-109 ◽  
Author(s):  
H. Harving ◽  
J. Korsgaard ◽  
R. Dahl
Keyword(s):  
House Dust ◽  
Environmental Conditions ◽  
House Dust Mites ◽  
Dust Mites

A dynamic model for human thermal comfort for smart building applications

2019 ◽  
Vol 234 (4) ◽  
pp. 472-483
Author(s):  
Ghezlane Halhoul Merabet ◽  
Mohamed Essaaidi ◽  
Driss Benhaddou
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Research Work ◽  
Comfort Level ◽  
Indoor Environments ◽  
Air Conditioning System ◽  
Human Thermal Comfort ◽  
Local Quality ◽  
Set Up ◽  
Air Conditioning Systems

Thermal comfort is closely related to the evaluation of heating, ventilation, and air conditioning systems. It can be seen as the result of the perception of the occupants of a given environment, and it is the product of the interaction of a number of personal and environmental factors. Otherwise, comfort issues still do not play an important role in the daily operation of commercial buildings. However, in the workplace, local quality effects, in addition to the health, the productivity that has a significant impact on the performance of the activities. In this regard, researchers have conducted, for decades, investigations related to thermal comfort and indoor environments, which includes developing models and indices through experimentations to establish standards to evaluate comfort and factors and set-up parameters for heating, ventilation, and air conditioning systems. However, to our best knowledge, most of the research work reported in the literature deals only with parameters that are not dynamically tracked. This work aims to propose a prototype for comfort measuring through a wireless sensor network and then presenting a model for thermal comfort prediction. The developed model can be used to set up a heating, ventilation, and air conditioning system to meet the expected comfort level. In particular, the obtained results show that there is a strong correlation between users’ comfort and variables such as age, gender, and body mass index as a function of height and weight.

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