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" Methods to Investigate Fine PM in Developing Countries: Spatial Distribution and Biological Responses "
Al Hanai, Ahlam Hilal
Schauer, James
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Latin Dissertation
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English
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| Record Number
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1052947
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TL52064
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| Main Entry
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Al Hanai, Ahlam Hilal
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| Title & Author
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Methods to Investigate Fine PM in Developing Countries: Spatial Distribution and Biological Responses\ Al Hanai, Ahlam HilalSchauer, James
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| College
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The University of Wisconsin - Madison
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| Date
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2019
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| Degree
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Ph.D.
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2019
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| Note
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148 p.
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| Abstract
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Exposure to fine particulate matter (PM2.5) contributed to 4.1 million premature deaths from respiratory and cardiovascular diseases, 91% of which occurred in low‐ and middle‐income countries. Yet, the mechanisms of how PM chemical characteristics drive adverse health outcomes are not fully understood. This research examines different approaches that can be applied in developing countries to improve ambient air quality. Low-cost PM monitors were used to investigate ambient PM2.5 concentrations and their spatial distribution over a period of 3 months in Muscat, Oman (Chapter 2). Two collocation tests were conducted before and after the field deployment of the PMS 3003 monitors to harmonize the monitors over the study period. The synchronized 1-hour averaged PM2.5 concentration was 12.69 ± 1.42 μg m−3 (range: 9.90–14.20 μg m−3). Inverse associations were shown between the measured PM2.5 concentrations and temperature (R = −0.29) and wind speed (R = −0.23). Positive correlations were displayed between 1-hour averaged PM2.5 concentration and Relative Humidity (R = 0.47) and wind direction (R = 0.10). This study provides a methodology for the use of low-cost sensors in regions without reference methods and will be particularly useful for future studies in remote parts of the world and those with limited resources. The associations between temporal and spatial variations in urban PM2.5 chemical composition, sources, and oxidative stress, inflammatory response, and gene expression were determined in an alveolar macrophage model. PM2.5 samples were collected from Tehran, Iran (Chapter 3) and two sites in the San Joaquin Valley (SJV), California: Fresno and Bakersfield (Chapter 4). The different chemical and source profiles of PM2.5 showed varied biological responses. Results from the two studies showed that ROS activity patterns were markedly different than those observed for the measured TNF-α. ROS activity was substantially higher in the colder months compared to the warm season. Whereas, TNF-α measured in summer and fall PM2.5 were generally higher compared to the rest of the year. The vehicles and residual oil combustion play a role in driving the oxidative potential of Tehran's PM2.5. However, mobile, winter-secondary organic aerosol (SOA), forest fire (FF), and SOA + FF are important sources promoting ROS activity in SJV sampling sites. A strong correlation was exhibited between diesel vehicles and TNF- α production during the cold season in Tehran. Whereas, summer-SOA and SOA + FF sources were significantly associated with increased TNF-a production in SJV sampling sites. A distinct gene expression profile was revealed for each sampling site with the anti-oxidant response and pro-inflammatory markers were the most regulated markers. Understanding the spatiotemporal variations in PM chemical composition and sources play a fundamental role in understanding the biological responses of PM.
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Environmental health
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Schauer, James
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The University of Wisconsin - Madison
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