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Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings

The objectives of this study were to measure levels of particulate matter (PM) in mechanically ventilated buildings and to improve understanding of filtration requirements to reduce exposure. With the use of an Ultra High Sensitivity Aerosol Spectrometer and an Aerodyne Mass Spectrometer, ultrafine...

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Autores principales: Miller, Shelly L., Facciola, Nick A., Toohey, Darin, Zhai, John
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334682/
https://www.ncbi.nlm.nih.gov/pubmed/28134841
http://dx.doi.org/10.3390/ijerph14020128
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author Miller, Shelly L.
Facciola, Nick A.
Toohey, Darin
Zhai, John
author_facet Miller, Shelly L.
Facciola, Nick A.
Toohey, Darin
Zhai, John
author_sort Miller, Shelly L.
collection PubMed
description The objectives of this study were to measure levels of particulate matter (PM) in mechanically ventilated buildings and to improve understanding of filtration requirements to reduce exposure. With the use of an Ultra High Sensitivity Aerosol Spectrometer and an Aerodyne Mass Spectrometer, ultrafine (0.055–0.1 μm) and fine (0.1–0.7 μm) indoor and outdoor PM was measured as a function of time in an office, a university building, and two elementary schools. Indoor particle levels were highly correlated with outdoor levels. Indoor and outdoor number concentrations in Denver were higher than those in Boulder, with the highest number concentrations occurring during summer and fall. The ratio of indoor-to-outdoor (I/O) PM was weakly but positively correlated with the amount of ventilation provided to the indoor environment, did not vary much with particle size (ranged between 0.48 and 0.63 for the entire size range), and was similar for each period of the week (weekend vs. weekday, night vs. day). Regression analyses showed that ultrafine indoor PM baseline concentrations were higher at night from nighttime infiltration. A lag time was observed between outdoor and indoor measurements. Weekday days had the shortest lag time of 11 min, and weekend nighttime lags when the HVAC was not in use were 50 to 148 min. Indoor-outdoor PM concentration plots showed ultrafine PM was more correlated compared to fine, and especially when the HVAC system was on. Finally, AMS data showed that most of the PM was organic, with occasional nitrate events occurring outdoors. During nitrate events, there were less indoor particles detected, indicating a loss of particulate phase nitrate. The results from this study show that improved filtration is warranted in mechanically ventilated buildings, particularly for ultrafine particles, and that nighttime infiltration is significant depending on the building design.
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spelling pubmed-53346822017-03-16 Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings Miller, Shelly L. Facciola, Nick A. Toohey, Darin Zhai, John Int J Environ Res Public Health Article The objectives of this study were to measure levels of particulate matter (PM) in mechanically ventilated buildings and to improve understanding of filtration requirements to reduce exposure. With the use of an Ultra High Sensitivity Aerosol Spectrometer and an Aerodyne Mass Spectrometer, ultrafine (0.055–0.1 μm) and fine (0.1–0.7 μm) indoor and outdoor PM was measured as a function of time in an office, a university building, and two elementary schools. Indoor particle levels were highly correlated with outdoor levels. Indoor and outdoor number concentrations in Denver were higher than those in Boulder, with the highest number concentrations occurring during summer and fall. The ratio of indoor-to-outdoor (I/O) PM was weakly but positively correlated with the amount of ventilation provided to the indoor environment, did not vary much with particle size (ranged between 0.48 and 0.63 for the entire size range), and was similar for each period of the week (weekend vs. weekday, night vs. day). Regression analyses showed that ultrafine indoor PM baseline concentrations were higher at night from nighttime infiltration. A lag time was observed between outdoor and indoor measurements. Weekday days had the shortest lag time of 11 min, and weekend nighttime lags when the HVAC was not in use were 50 to 148 min. Indoor-outdoor PM concentration plots showed ultrafine PM was more correlated compared to fine, and especially when the HVAC system was on. Finally, AMS data showed that most of the PM was organic, with occasional nitrate events occurring outdoors. During nitrate events, there were less indoor particles detected, indicating a loss of particulate phase nitrate. The results from this study show that improved filtration is warranted in mechanically ventilated buildings, particularly for ultrafine particles, and that nighttime infiltration is significant depending on the building design. MDPI 2017-01-28 2017-02 /pmc/articles/PMC5334682/ /pubmed/28134841 http://dx.doi.org/10.3390/ijerph14020128 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Miller, Shelly L.
Facciola, Nick A.
Toohey, Darin
Zhai, John
Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings
title Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings
title_full Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings
title_fullStr Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings
title_full_unstemmed Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings
title_short Ultrafine and Fine Particulate Matter Inside and Outside of Mechanically Ventilated Buildings
title_sort ultrafine and fine particulate matter inside and outside of mechanically ventilated buildings
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334682/
https://www.ncbi.nlm.nih.gov/pubmed/28134841
http://dx.doi.org/10.3390/ijerph14020128
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