Preliminary assessment of BTEX concentrations in indoor air of residential buildings and atmospheric ambient air in Ardabil, Iran

Due to unprecedented urbanization, UAE had built many new residential projects with poor choices of material and ventilation. This social phenomenon is leading UAE to Sick Building Syndrome (SBS) faster than any other countries. The Dubai Municipality regulates the indoor air quality with strict stipulation, but the detailed regulations are still insufficient. The objective of this paper is to measure the indoor air quality of new residential projects in Dubai to suggest the improvement of the regulations for indoor air quality. As a methodology, a field survey was conducted to investigate the status of indoor air pollution in residential buildings. Based on the field survey data, lab experiments for building materials were conducted and a computer simulation on radon gas was conducted. The result had shown that radon gas was mainly detected in new townhouses and labor camp houses, and its concentration was found to exceed the standard. Volatile organic solvents (VOCs) and formaldehyde (CH2O) were mainly detected in showhouses and new townhouses, and the concentration distribution was about 10 times higher than that of outdoors. It was proven that emission concentration of radon gas from various building materials were detected, and the order was red clay, gypsum board, and concrete. Volatile organic solvents (VOCs) are mainly detected in oil paints and PVC floor and the radiation amount of all pollutants increased with temperature increase. In computer simulation, it was found that a new townhouse needs a grace period from 20 days to 6 months to lower the radon gas concentration by 2 pCi/L. This study will serve as a basic data to establish more detailed regulation for the building materials and improve the IAQ standards in Dubai.

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Field Study of Metal Oxide Semiconductor Gas Sensors in Temperature Cycled Operation for Selective VOC Monitoring in Indoor Air

Atmosphere ◽

10.3390/atmos12050647 ◽

2021 ◽

Vol 12 (5) ◽

pp. 647

Author(s):

Tobias Baur ◽

Johannes Amann ◽

Caroline Schultealbert ◽

Andreas Schütze

Keyword(s):

Air Quality ◽

Metal Oxide ◽

Gas Sensor ◽

Gas Sensors ◽

Indoor Air ◽

Ambient Air ◽

Quantitative Agreement ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

High Temporal Resolution

More and more metal oxide semiconductor (MOS) gas sensors with digital interfaces are entering the market for indoor air quality (IAQ) monitoring. These sensors are intended to measure volatile organic compounds (VOCs) in indoor air, an important air quality factor. However, their standard operating mode often does not make full use of their true capabilities. More sophisticated operation modes, extensive calibration and advanced data evaluation can significantly improve VOC measurements and, furthermore, achieve selective measurements of single gases or at least types of VOCs. This study provides an overview of the potential and limits of MOS gas sensors for IAQ monitoring using temperature cycled operation (TCO), calibration with randomized exposure and data-based models trained with advanced machine learning. After lab calibration, a commercial digital gas sensor with four different gas-sensitive layers was tested in the field over several weeks. In addition to monitoring normal ambient air, release tests were performed with compounds that were included in the lab calibration, but also with additional VOCs. The tests were accompanied by different analytical systems (GC-MS with Tenax sampling, mobile GC-PID and GC-RCP). The results show quantitative agreement between analytical systems and the MOS gas sensor system. The study shows that MOS sensors are highly suitable for determining the overall VOC concentrations with high temporal resolution and, with some restrictions, also for selective measurements of individual components.

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The impact of mechanical ventilation operation strategies on indoor CO2 concentration and air exchange rates in residential buildings

Indoor and Built Environment ◽

10.1177/1420326x20960767 ◽

2020 ◽

pp. 1420326X2096076

Author(s):

Pedro F. Pereira ◽

Nuno M. M. Ramos

Keyword(s):

Mechanical Ventilation ◽

Air Quality ◽

Exchange Rates ◽

Indoor Air Quality ◽

Indoor Air ◽

Residential Buildings ◽

Ventilation Strategy ◽

The Impact ◽

Mechanical Extraction ◽

Air Exchange

In Portugal, residential buildings commonly have their ventilation strategy changed after commissioning. This occurs due to the building managers' willingness to reduce shared costs with the electricity needed for fan operation. However, this option is not technically supported, and the effects of such a strategy on indoor air quality-related to human pollutants are yet to be quantified. CO2 was monitored in 15 bedrooms and air exchange rates were calculated for each room. The air exchange rate values ranged from 0.18 to 0.53 h−1 when mechanical extraction ventilation was off, and from 0.45 to 0.90 h−1 when mechanical extraction ventilation was on, which represents an average increase of 119%. With the current intermittent ventilation strategy, all rooms remain above 1500 ppm for a given percentage of time, and 12 rooms presenting CO2 concentrations above 2000 ppm. Simulations of theoretical CO2 concentrations, for a non-interrupted mechanical ventilation strategy show that no rooms would accumulate CO2 concentrations above 2000 ppm, and only 25% would present CO2 concentrations above 1500 ppm. Pearson correlations between the monitored CO2 and human and spatial factors identified two relevant parameters. Those parameters correspond to ratios between CO2 generation and floor area ([Formula: see text]), and airflow with CO2 generation ([Formula: see text]). The proposed ratios could be used as ways to optimise ventilation costs and indoor air quality.

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Preliminary assessment of BTEX exposure levels in urban ambient air and public buses: A pilot study conducted in Paramaribo, Suriname

Case Studies in Chemical and Environmental Engineering ◽

10.1016/j.cscee.2021.100112 ◽

2021 ◽

pp. 100112

Author(s):

Jelissa Lindsey Doornkamp ◽

Nykieta Annmarie James ◽

Sumeet Ori ◽

Grace-Anne Bent

Keyword(s):

Pilot Study ◽

Ambient Air ◽

Preliminary Assessment ◽

Exposure Levels

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Impact of façade design on indoor air temperatures and cooling loads in residential buildings in the tropical climate

Energy and Buildings ◽

10.1016/j.enbuild.2021.110972 ◽

2021 ◽

Vol 243 ◽

pp. 110972

Author(s):

Shanshan Tong ◽

Jianxiu Wen ◽

Nyuk Hien Wong ◽

Erna Tan

Keyword(s):

Indoor Air ◽

Residential Buildings ◽

Tropical Climate ◽

Air Temperatures ◽

Cooling Loads

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Removal of contaminants in indoor air by using green plant treated with titanium dioxide nanoparticles

10.21203/rs.2.11822/v1 ◽

2019 ◽

Author(s):

Khaled Fikry salama ◽

Mubashir Zafar Zafar

Keyword(s):

Air Pollution ◽

Titanium Dioxide ◽

Indoor Air ◽

Indoor Air Pollution ◽

Titanium Dioxide Nanoparticles ◽

Plant Root ◽

Ambient Air ◽

Green Plant ◽

Growth Media ◽

Novel Approach

Abstract Background: Indoor air pollution is important environmental health problem. Nanotechnology is one of the most important methods to reduce the air pollution. The aim of this study to determine the effectiveness of nanotechnology for removal of toxic air indoor pollution by using Saudi myrtle plants treated with titanium dioxide. Methods: Experiments were conducted in the two academic departments of labs at public sector universities. Aplying titanium dioxide-containing growth media to at least one of a Myrtus communis plant root, stem, and leaf. Growing the plant in the growth media, a gel growth media, or both; exposing the plant to contaminant-containing air Results: It is found that the levels of formaldehyde, Volatile organic compounds and other pollutants were significantly reduced the concentration from 10% to 98% in air. The duration of the intervention from 4 hours to 8 hours, Air containing the concentration of NO2 SO2, formaldehyde, TVOCs and CO reduced from range of 0.3 ppm- 0.4ppm to range of 0.1ppm -0.3 ppm after exposure of Myrtus plant to ambient air and duration of the exposure is 4 hours to 8 hours. Conclusion: Application of Tio2 in green plant specially Mytrus Communis is a novel approach for reduction of concentrations of harmful gaseous toxic and carcinogenic air pollutants in indoor environment.

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