scholarly journals Surface reservoirs dominate dynamic gas-surface partitioning of many indoor air constituents

2020 ◽  
Vol 6 (8) ◽  
pp. eaay8973 ◽  
Author(s):  
Chen Wang ◽  
Douglas B. Collins ◽  
Caleb Arata ◽  
Allen H. Goldstein ◽  
James M. Mattila ◽  
...  
Keyword(s):  
Gas Phase ◽  
Indoor Air ◽  
Indoor Environment ◽  
Phase Distribution ◽  
Chemical Exposure ◽  
Fast Response ◽  
Air Contaminants ◽  
Surface Partitioning ◽  
On Line ◽  
Distinctive Aspect

Human health is affected by indoor air quality. One distinctive aspect of the indoor environment is its very large surface area that acts as a poorly characterized sink and source of gas-phase chemicals. In this work, air-surface interactions of 19 common indoor air contaminants with diverse properties and sources were monitored in a house using fast-response, on-line mass spectrometric and spectroscopic methods. Enhanced-ventilation experiments demonstrate that most of the contaminants reside in the surface reservoirs and not, as expected, in the gas phase. They participate in rapid air-surface partitioning that is much faster than air exchange. Phase distribution calculations are consistent with the observations when assuming simultaneous equilibria between air and large weakly polar and polar absorptive surface reservoirs, with acid-base dissociation in the polar reservoir. Chemical exposure assessments must account for the finding that contaminants that are fully volatile under outdoor air conditions instead behave as semivolatile compounds indoors.

scholarly journals Assessment of Gas–Particle Phase Distribution and Source Apportionment of Atmospheric Phthalate Esters and Volatile Methyl Siloxanes in Vietnamese Micro-Environments

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Hoang Quoc Anh ◽  
Le Thi Hanh ◽  
Dang Minh Huong Giang ◽  
Nguyen Thi Thanh Huyen ◽  
Chu Ngoc Chau ◽  
...  
Keyword(s):  
Gas Phase ◽  
Source Apportionment ◽  
Indoor Air ◽  
Phase Distribution ◽  
Phthalate Esters ◽  
Consumer Products ◽  
Emission Sources ◽  
Particle Phase ◽  
Ethylhexyl Phthalate ◽  
Total Concentrations

In this study, the gas–particle distribution characteristics and emission sources of phthalate esters (PAEs) and volatile methyl siloxanes (VMSs) were evaluated for indoor air samples collected from different micro-environments such as homes, offices, kindergartens, hair salons, laboratories, and cars in 4 cities and provinces of Hanoi, Bac Ninh, Thai Binh, and Tuyen Quang, northern Vietnam. In general, total concentrations of PAEs and VMSs were higher in gas phase as compared to particle phase; however, phase distribution profiles of individual compounds were strongly related to their structures and physicochemical properties. For examples, low-molecular-weight compounds such as dimethyl phthalate, diethyl phthalate, D3, D4, L4, and L5 were more abundant in gas phase, while heavier compounds like di(2-ethylhexyl) phthalate and L8 were preferentially associated with particle phase. Assessment of PAE emission sources is relatively difficult because they have been applied in different consumer products and materials. Significant correlation between cyclic VMSs (e.g., D4, D5, and D6) was observed, suggesting their applications in cosmetics and personal care products. Keywords: Phthalate esters, volatile methyl siloxanes, indoor air, phase distribution, source apportionment.  

scholarly journals Effects of room airflow on accurate determination of PUF-PAS sampling rates in the indoor environment

2018 ◽  
Vol 20 (5) ◽  
pp. 757-766 ◽  
Author(s):  
Nicholas J. Herkert ◽  
Keri C. Hornbuckle
Keyword(s):  
Indoor Air ◽  
Indoor Environment ◽  
Accurate Determination ◽  
Passive Samplers ◽  
Air Toxics ◽  
Precise Interpretation

Accurate and precise interpretation of concentrations from polyurethane passive samplers (PUF-PAS) is important as more studies show elevated concentrations of PCBs and other semivolatile air toxics in indoor air of schools and homes.

Computational Modeling of Particulate Pollutant Transport in a Ventilated Room in the Presence of Two Heated Breathing and Rotating Manikins

2017 ◽  
Author(s):  
Seyed Ali Keshavarz ◽  
Mazyar Salmanzadeh ◽  
Goodarz Ahmadi
Keyword(s):  
Air Quality ◽  
Computational Modeling ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Rotational Motion ◽  
Indoor Environment ◽  
Ventilation System ◽  
Thermal Plume ◽  
Displacement Ventilation ◽  
Simulation Results

Recently, attention has been given to indoor air quality due to its serious health concerns. Clearly the dispersion of pollutant is directly affected by the airflow patterns. The airflow in indoor environment is the results of a combination of several factors. In the present study, the effects of thermal plume and respiration on the indoor air quality in a ventilated cubicle were investigated using an unsteady computational modeling approach. The person-to-person contaminant transports in a ventilated room with mixing and displacement ventilation systems were studied. The effects of rotational motion of the heated manikins were also analyzed. Simulation results showed that in the cases which rotational motion was included, the human thermal plume and associated particle transport were significantly distorted. The distortion was more noticeable for the displacement ventilation system. Also it was found that the displacement ventilation system lowered the risk of person-to-person transmission in an office space in comparison with the mixing ventilation system. On the other hand the mixing system was shown to be more effective compared to the displacement ventilation in removing the particles and pollutant that entered the room through the inlet air diffuser.

An On-Line Isocratic HPLC System for the Analysis of PTH-Amino Acids on A Gas-Phase Sequencer

Proteins ◽  
1987 ◽  
pp. 383-394
Author(s):  
J. E. Shively ◽  
D. Hawke ◽  
R. M. Kutny ◽  
B. Krieger ◽  
J. L. Glajch
Keyword(s):  
Amino Acids ◽  
Gas Phase ◽  
Hplc System ◽  
On Line ◽  
Isocratic Hplc

scholarly journals Achieving a healthy indoor environment by using an emissions barrier for stopping spread of chemicals from building into the indoor air

2021 ◽  
Author(s):  
Johan Mattsson ◽  
Lennart Larsson
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Indoor Air ◽  
Aromatic Hydrocarbons ◽  
Indoor Environment ◽  
Concrete Slab ◽  
Treated Wood ◽  
Volatile Organic ◽  
Polycyclic Aromatic

An emissions barrier was used in premises with indoor air complaints due to emissions from the buildings in question. The emissions comprised chlorophenols/chloroanisoles and polycyclic aromatic hydrocarbons (PAH) from treated wood, and volatile organic compounds (VOC), mainly 2-ethylhexanol, from PVC flooring and the glue used to paste the flooring onto a concrete slab. Attaching the barrier at the surfaces from where the emissions were spread (floor, walls, ceiling) resulted in a fresh and odour-free indoor air. We conclude that using an emissions barrier in buildings made unhealthy by moisture is an efficient way of restoring a pleasant and healthy indoor air.

scholarly journals The Perception of the Indoor Environment Quality (IEQ) of Private Hostels in Ifite-Awka, Nigeria

2020 ◽  
pp. 61-70
Author(s):  
F. O. Ezeokoli ◽  
C. A. Omenyi ◽  
C. B. N. Bert- Okonkwo ◽  
N. B. Iheama
Keyword(s):  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Environment ◽  
Light Quality ◽  
Anambra State ◽  
Environment Quality ◽  
Direct Observations ◽  
Literature Searches ◽  
Indoor Environment Quality ◽  
Inadequate Ventilation

This study aimed at evaluating the indoor environment conditions of the private hostels in Ifite Awka Anambra state with a view to establishing its quality and impacts on students dwelling on these hostels in the study area. Being a survey research, the study was affected by the use of questionnaire, literature searches and direct observations. Accordingly, a total of 311 questionnaires were administered while 258 questionnaires which represent 83% were returned and found useful. The study found that IEQ parameters of hostels in study area are: Indoor air quality was poor due to inadequate ventilation of rooms; thermal comfort of rooms was found to be warm; indoor light quality was found good and the acoustics comfort and noise slightly good and to some extent poor. Therefore, the study recommended that during the design and construction of buildings, IEQ parameters should be considered, so as to obtain a quality indoor environment.

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