Turbulence Effect of Urban-Canopy Flow on Indoor Velocity Fields under Sheltered and Cross-Ventilation Conditions

Understanding the characteristics of natural, wind-induced ventilation of buildings is essential for accurate predictions of ventilation flow rates; however, indoor ventilation is significantly influenced by surrounding buildings. Therefore, a series of wind-tunnel experiments were performed to clarify the relationship between outdoor and indoor air flows around and within a target cube model with several openings. Two surrounding building arrangements, namely square (SQ) and staggered (ST), were placed under the condition of a building coverage ratio of 25%. The results indicated that the wind speed near the windward openings on the streamwise faces showed 0.3 to the reference wind speed, whereas those on the lateral faces were less than 0.1; these numbers indicate that the opening positions significantly affect the mean indoor wind speed. Furthermore, the temporal fluctuations of velocities near the opening demonstrated that the introduction of the flow is significantly affected by turbulent flow due to the surrounding buildings. In addition, correlation between the outdoor and indoor air flows was observed. The highest correlations were obtained for both opening conditions with a certain temporal delay. This result indicates that indoor air flows become turbulent because of the turbulent flows generated by the surrounding outdoor buildings; however, slight temporal delays could occur between indoor and outdoor air flows. Although the present study focuses on the fundamental turbulent characteristics of indoor and outdoor air flows, such findings are essential for accurately predicting the ventilation flow rate due to turbulent air flows for sheltered buildings.

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Characterization of Bacteria and Fungi Bioaerosol in the Indoor Air of selected Primary Schools in Malaysia

Indoor and Built Environment ◽

10.1177/1420326x11414318 ◽

2011 ◽

Vol 20 (6) ◽

pp. 607-617 ◽

Cited By ~ 31

Author(s):

Nor Husna Mat Hussin ◽

Lye Munn Sann ◽

Mariana Nor Shamsudin ◽

Zailina Hashim

Keyword(s):

Indoor Air ◽

Primary Schools ◽

Average Concentration ◽

Outdoor Air ◽

Inadequate Ventilation ◽

Bacillus Spp ◽

Bacteria And Fungi ◽

Staphylococcus Spp ◽

Indoor And Outdoor

This study reports the types and concentrations of bacterial and fungal bioaerosols found in five randomly selected primary schools in Malaysia. Normal flora bacteria was the most frequently isolated bacteria including Staphylococcus spp., Pseudomonas spp. and Bacillus spp. Terribacillus spp. found in this study had never been reported before. The most frequently isolated fungal genera were Aspergillus, Penicillium, Fusarium, Rhizopus and Zygomycetes. The average concentration of bacteria in indoor and outdoor air were 1025 ± 612 CFU/m3 and 1473 ± 1261 CFU/m3, respectively, while the average concentration of fungal bioaerosol in indoor and outdoor air were 292 ± 83 CFU/m3 and 401 ± 235 CFU/m3, respectively. The percentages of bacterial and fungal samples that were within the American Conference of Industrial Hygenists (ACGIH) recommended levels were 44% and 33.8%, respectively. The ratio of indoor to outdoor fungi concentration was below 1.0, suggesting minimal indoor generative source for fungal bioaerosols. However, the ratio of indoor to outdoor bacteria concentration was approaching 1.0, suggesting the presence of potential internal generative source and inadequate ventilation. Building occupants might be one of the potential sources of bacteria in the indoor air as the bacteria concentrations without occupants were significantly lower than with occupants (p < 0.05).

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Indoor Air Quality Investigation at Primary Classrooms in Hamirpur, Himachal Pradesh, India

Hydro Nepal Journal of Water Energy and Environment ◽

10.3126/hn.v24i0.23583 ◽

2019 ◽

Vol 24 ◽

pp. 45-48 ◽

Cited By ~ 1

Author(s):

Venu Shree ◽

Bhanu M. Marwaha ◽

Pamita Awasthi

Keyword(s):

Air Quality ◽

Relative Humidity ◽

Indoor Air ◽

Himachal Pradesh ◽

Building Performance ◽

Outdoor Air ◽

Primary Classrooms ◽

Outdoor Air Quality ◽

Hybrid Ventilation ◽

Indoor And Outdoor

Two schools in Hamirpur (Himachal Pradesh, India) having hybrid ventilation (ceiling fan) were selected for indoor and outdoor air quality investigation. Investigated parameters include temperature, relative humidity, CO2, and PM2.5 for both indoor and outdoor air quality. The average concentrations of CO2, and PM2.5 are estimated for indoor and outdoor air quality. Result shows that adopted building performance is not good in comparison with designed ones. The indoor concentrations of various pollutants are found to be higher in comparison with outdoor, so there is an urgent need to reduce the levels of pollutants inside the primary classrooms.

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Determination of Lead, Cations, and Anions Concentration in Indoor and Outdoor Air at the Primary Schools in Kuala Lumpur

Journal of Environmental and Public Health ◽

10.1155/2014/408275 ◽

2014 ◽

Vol 2014 ◽

pp. 1-3 ◽

Cited By ~ 1

Author(s):

Normah Awang ◽

Farhana Jamaluddin

Keyword(s):

Indoor Air ◽

Primary Schools ◽

Motor Vehicles ◽

Kuala Lumpur ◽

Outdoor Air ◽

Congested Traffic ◽

Suspended Particulates ◽

Vehicles Emissions ◽

Indoor And Outdoor

This study was carried out to determine the concentration of lead (Pb), anions, and cations at six primary schools located around Kuala Lumpur. Low volume sampler (MiniVolPM10) was used to collect the suspended particulates in indoor and outdoor air. Results showed that the concentration of Pb in indoor air was in the range of 5.18 ± 1.08 μg/g–7.01 ± 0.08 μg/g. All the concentrations of Pb in indoor air were higher than in outdoor air at all sampling stations. The concentrations of cations and anions were higher in outdoor air than in indoor air. The concentration ofCa2+(39.51 ± 5.01 mg/g–65.13 ± 9.42 mg/g) was the highest because the cation existed naturally in soil dusts, while the concentrations ofNO3-andSO42-were higher in outdoor air because there were more sources of exposure for anions in outdoor air, such as highly congested traffic and motor vehicles emissions. In comparison, the concentration ofNO3-(29.72 ± 0.31 μg/g–32.00 ± 0.75 μg/g) was slightly higher thanSO42-. The concentrations of most of the parameters in this study, such asMg2+,Ca2+,NO3-,SO42-, andPb2+, were higher in outdoor air than in indoor air at all sampling stations.

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Indoor Air Pollution as an Environmental Factor

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193127602001403 ◽

1976 ◽

Vol 20 (14) ◽

pp. 272-276

Author(s):

Joshi Satish

Keyword(s):

Air Pollution ◽

Indoor Air ◽

Indoor Air Pollution ◽

Well Being ◽

Outdoor Air ◽

Average Person ◽

Sampling Program ◽

The City ◽

Indoor And Outdoor

An average person spends most of his time indoors and the quality of indoor air affects his performance and well-being. This justifies the study of indoor air pollution for the development of working and living environments which are comfortable and safe. As a part of a larger program to study traffic-generated air pollution in the vicinity of streets, a simultaneous indoor/outdoor sampling program was carried out at three sites in the city of Zurich, Switzerland. Parameters included CO, NO, NO2 and HCHO. The results show the direct relationship between indoor and outdoor concentrations of CO, NO and NO2. HCHO concentrations were found to be substantially higher indoors than ourdoors thus supporting the hypothesis that HCHO source could be in the buildings themselves. The importance of indoor air is emphasized, and the interplay of indoor and outdoor air pollution is demonstrated.

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The identification of Volatile Organic Compound’s emission sources in indoor air of living spaces, offices and laboratories

E3S Web of Conferences ◽

10.1051/e3sconf/20182801018 ◽

2018 ◽

Vol 28 ◽

pp. 01018

Author(s):

Beata Kultys

Keyword(s):

Air Quality ◽

Indoor Air ◽

Correlation Coefficients ◽

Well Being ◽

Emission Sources ◽

Outdoor Air ◽

Volatile Organic ◽

Sick Building ◽

Work Type ◽

Indoor And Outdoor

Indoor air quality is important because people spend most of their time in closed rooms. If volatile organic compounds (VOCs) are present at elevated concentrations, they may cause a deterioration in human well-being or health. The identification of indoor emission sources is carried out by comparison indoor and outdoor air composition. The aim of the study was to determinate the concentration of VOCs in indoor air, where there was a risk of elevated levels due to the kind of work type carried out or the users complained about the symptoms of a sick building followed by an appropriate interpretation of the results to determine whether the source of the emission in the tested room occurs. The air from residential, office and laboratory was tested in this study. The identification of emission sources was based on comparison of indoor and outdoor VOCs concentration and their correlation coefficients. The concentration of VOCs in all the rooms were higher or at a similar level to that of the air sampled at the same time outside the building. Human activity, in particular repair works and experiments with organic solvents, has the greatest impact on deterioration of air quality.

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Microplastics Differ Between Indoor and Outdoor Air Masses: Insights from Multiple Microscopy Methodologies

Applied Spectroscopy ◽

10.1177/0003702820920652 ◽

2020 ◽

Vol 74 (9) ◽

pp. 1079-1098 ◽

Cited By ~ 4

Author(s):

Emily Gaston ◽

Mary Woo ◽

Clare Steele ◽

Suja Sukumaran ◽

Sean Anderson

Keyword(s):

Indoor Air ◽

Fluorescent Microscopy ◽

Inhalation Exposure ◽

Nile Red ◽

Outdoor Air ◽

Air Masses ◽

Ft Ir ◽

Abundance And Distribution ◽

Microscopy Techniques ◽

Indoor And Outdoor

The abundance and distribution of microplastic (<5 mm) has become a growing concern, particularly over the past decade. Research to date has focused on water, soil, and organism matrices but generally disregarded air. We explored airborne microplastic inside and outside of buildings in coastal California by filtering known volumes of air through glass fiber filters, which were then subsequently characterized with a variety of microscopy techniques: gross traditional microscopy, fluorescent microscopy following staining with Nile red, micro-Raman spectroscopy, and micro-Fourier transform infrared (µFT-IR) spectroscopy. Microplastics permeated the air, with indoor (3.3 ± 2.9 fibers and 12.6 ± 8.0 fragments m–3; mean ± 1 SD) harboring twice as much as outdoor air (0.6 ± 0.6 fibers and 5.6 ± 3.2 fragments m–3). Microplastic fiber length did not differ significantly between indoor and outdoor air, but indoor microplastic fragments (58.6 ± 55 µm) were half the size of outdoor fragments (104.8 ± 64.9 µm). Micro-Raman and FT-IR painted slightly different pictures of airborne plastic compounds, with micro-Raman suggesting polyvinyl chloride dominates indoor air, followed by polyethylene (PE) and µFT-IR showing polystyrene dominates followed by PE and polyethylene terephthalate. The ubiquity of airborne microplastic points to significant new potential sources of plastic inputs to terrestrial and marine ecosystems and raises significant concerns about inhalation exposure to humans both indoors and outdoors.

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Indoor and Outdoor Air Contaminants Coupling Relationship and Measures of Improving Indoor Air Quality

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.178-181.711 ◽

2012 ◽

Vol 178-181 ◽

pp. 711-717

Author(s):

Shi Bin Geng ◽

Ming Xing Xiao

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Physical Models ◽

Air Purification ◽

Outdoor Air ◽

Air Contaminants ◽

Air Filter ◽

Coupling Relationship ◽

Indoor And Outdoor

This article use several different physical models to describe coupling relationship between indoor and outdoor air contaminants ,analysis the principle of the air filter air purification, discuss all the filters’ roles in improving IAQ.

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Particulate matter in indoor spaces: known facts and the knowledge gaps

Annals of Warsaw University of Life Sciences – SGGW Land Reclamation ◽

10.1515/sggw-2015-0013 ◽

2015 ◽

Vol 47 (1) ◽

pp. 43-54 ◽

Cited By ~ 1

Author(s):

Patrycja Rogula-Kopiec ◽

Józef S. Pastuszka ◽

Wioletta Rogula-Kozłowska ◽

Grzegorz Majewski

Keyword(s):

Air Pollution ◽

Particulate Matter ◽

Indoor Air ◽

Indoor Air Pollution ◽

Outdoor Air ◽

Knowledge Gaps ◽

Indoor Space ◽

The World ◽

Indoor Spaces ◽

Indoor And Outdoor

Abstract: Particulate matter in indoor spaces: known facts and the knowledge gaps. As people spend most of the time in closed spaces (flats, workplaces, schools etc.), the indoor air has been researched for many years all over the world. Particulate matter (PM) is one of the most often examined pollutants in the indoor and outdoor air. The following study presents the facts about PM in closed spaces and the most often taken actions. The least known aspects related to the indoor air pollution with PM are demonstrated. The indoor space of various service and office buildings/facilities (not related to production, i.e. offices, shops, beauty parlours, restaurant kitchens, restaurants, pubs etc.) seem to be an unrecognized area in the air pollution studies. Importantly, a great number of people work in such spaces all over the world and thus spend there a large part of their lives.

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Exposure of pig fatteners and dairy cows to polycyclic aromatic hydrocarbons

Veterinární Medicína ◽

10.17221/5817-vetmed ◽

2012 ◽

Vol 47 (No. 5) ◽

pp. 137-142 ◽

Cited By ~ 12

Author(s):

M. Ciganek ◽

R. Ulrich ◽

J. Nea ◽

J. Raszyk

Keyword(s):

Polycyclic Aromatic Hydrocarbons ◽

Dairy Cows ◽

Indoor Air ◽

Aromatic Hydrocarbons ◽

Road Dust ◽

Outdoor Air ◽

Polycyclic Aromatic ◽

Exposure Routes ◽

Cattle Farms ◽

Indoor And Outdoor

Exposure of pig fatteners and dairy cows to polycyclic aromatic hydrocarbons (PAHs) was investigated by analyses of selected indoor and outdoor samples. PAH concentrations (16 U.S. EPA priority PAHs) and data on common exposure routes were used for exposure calculations.  The samples under study included water (n = 24), feed (n = 48), indoor air (n = 15), barn dust (n = 17), outdoor air (n = 6) road dust (n = 17), and soil (n = 15) collected in the summer 1999 and in the spring 2000 on 3 pig and 2 dairy cattle farms. The following mean concentrations of  16 PAHs were found: 100 ng/l in water for pigs, 38 ng/l in water for cows, 82 µg/kg in feed mixtures for pigs, 128 µg/kg in feed concentrates for cows, 278 µg/kg in forages for dairy cows, 25 ng/m3 in indoor air of pig houses, 59 ng/m3 in indoor air of  cow houses, 676 µg/kg in dust collected in pig houses, 4 475 µg/kg in dust collected in cow houses, 16 ng/m3 in outdoor air of pig houses, 29 ng/m3 in outdoor air of  cow houses, 4 711 µg/kg in road dust collected on pig farms, 15 175 µg/kg in road dust collected on cattle farms, 826 µg/kg in soil collected around pig houses, and 1 356 µg/kg in soil collected around cow houses. The total intake of  16 PAHs in the diet of cows and pigs was 14 156 µg and 164 µg PAHs per day, respectively. The exposure of cows to PAHs was 86 times higher than that of pigs. Feed was the major source of PAHs for both species (approximately 99%). Urinary 1-hydroxypyrene concentration was used as a biomarker of exposure to PAHs. The mean total amount of 1-hydroxypyrene excreted per day in porcine (2 l) and bovine (13 l) urine was 14.5 µg  and 1 595 µg, respectively, which was 3.2% and 11.9% of pyrene intake.

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Simultaneous Liquid Chromatographic Determination of 39 Polycyclic Aromatic Hydrocarbons in Indoor and Outdoor Air and Application to a Survey on Indoor Air Pollution in Fuji, Japan

Journal of AOAC International ◽

10.1093/jaoac/85.1.188 ◽

2002 ◽

Vol 85 (1) ◽

pp. 188-202 ◽

Cited By ~ 19

Author(s):

Takeshi Ohura ◽

Tomohiko Sugiyama ◽

Takashi Amagai ◽

Masahiro Fusaya ◽

Hidetsuru Matsushita

Keyword(s):

Air Pollution ◽

Polycyclic Aromatic Hydrocarbons ◽

Indoor Air ◽

Aromatic Hydrocarbons ◽

Indoor Air Pollution ◽

Chromatographic Determination ◽

Outdoor Air ◽

Polycyclic Aromatic ◽

Indoor And Outdoor

Abstract An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999–2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.

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