Several studies indicate that the cabin of buses is the micro-environment in urban public transport where commuters might be the most exposed to black carbon. Black carbon functions as an indicator of air pollution, which is shown to have harmful impacts on the human body and because it may lead to cancers, systemic inflammation, and cardiovascular diseases, it is listed as one of the top causes to premature deaths, globally. This makes it important to understand what mechanisms there are to the elevated levels of pollutants in urban buses, and by performing mobile in-cabin measurements of black carbon concentrations during 55 bus trips in the public transport system of Stockholm, this study have tried to assess the influences from using different types of fuel, self-contamination, meteorological conditions and driving factors. Although concentrations showed large variability both spatially and temporally, idling at intensely trafficked bus stops showed an average increase of concentrations by 42% compared to the overall average. The risk of allowing increased number of pollutants at bus stops increases with idling for longer time and having the doors open meanwhile.

Significant differences occurred in the density of tardigrades, rotifers, and nematodes and the diversity of tardigrades between collecting sites located upwind and downwind from a coal-burning power plant in Missouri. The oak tree species and lichen genera also varied in the two areas. Tardigrade and rotifer densities were greater in upwind sites, whereas nematode density was higher in downwind samples. One tardigrade species (Ramazzottius sp.) was found only at the upwind sites, and one species (Echiniscus sp.) was only in the downwind samples. In contrast, three species (Macrobiotus sp., Minibiotus sp., and Milnesium tardigradum) were found both upwind and downwind but in different densities in the two areas. The study presents baseline data for long-term monitoring of the effects of environmental factors on nematode and rotifer densities as well as tardigrade density and diversity.

付記する学位プログラム名: グローバル生存学大学院連携プログラム / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第23174号 / 工博第4818号 / 新制||工||1753(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 CRUZ Ana Maria , 教授 米田 稔, 准教授 横松 宗太 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Air pollution is a major concern in heavily populated cities such as Los-Angeles, California. Particulate Matter (PM) pollution in Hispanic and Black American neighborhoods in Los Angeles tends to be higher than adjacent non-minority areas. Research has indicated that certain carbon-storing trees can be used to reduce PM pollution. The purpose of this qualitative, interview research project was to determine the feasibility of using carbon-storing trees to reduce PM pollution in Hispanic and Black American neighborhoods in Los Angeles. Using an ecological theoretical framework, 10 subject matter experts were interviewed about their knowledge of carbon-storing properties and the feasibility of planting 10 different types of trees to reduce PM in the target neighborhoods. The results indicated that oak and pine trees are the most feasible in accomplishing PM reduction within the target areas based on factors like leaf structure, size, and adaptation to Southern California climate and soil. The least feasible trees included California sycamore, Fremont cottonwood, ox horn bamboos, American sweetgum, and yellow poplar. Public health officials may use this study's findings to bring social change to communities by encouraging the development and implementation of tree planting plans that may reduce PM pollution for all populations across the United States. The responsibility of implementing a tree planting strategy would be up to city planners and public health officials (stakeholders) in affected communities. To accomplish this, stakeholders would need to determine the financial costs and specific locations for planting oak and pine trees.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17794号 / エネ博第277号 / 新制||エネ||58(附属図書館) / 30601 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 東野 達, 教授 坂 志朗, 教授 米田 稔 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

The use of Positive Matrix Factorization (PMF) in pollution source apportionment (PSA) is examined and illustrated. A study of its settings is conducted in order to optimize them in the context of PSA. The use of a priori information in PMF is examined, in the form of target factor profiles and pulling profile elements to zero. A Bayesian model using lognormal prior distributions for source profiles and source contributions is fit and examined.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22060号 / 工博第4641号 / 新制||工||1724(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高野 裕久, 教授 米田 稔, 准教授 上田 佳代 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Though the high prevalence of biomass fuel use in the developing world is widely known, the use of burning biomass for cooking and heating in the developed world is under-recognized. Combustion materials including coal and wood are also used for heating in some areas of the United States. We conducted a pilot study to assess the feasibility of conducting indoor environmental monitoring in rural Appalachia. We sought to explore the type of biomass being used for home heating and its impact upon indoor air quality in non-heating and heating seasons. Residential indoor air monitoring for particulate matter (PM) and nitrogen dioxide (NO) was conducted in Lee County, Virginia. Homes had evidence of poor indoor air quality with high concentrations of indoor PM and a large burden of cigarette smoking. Further characterization of indoor combustion material use in this region to determine the health impacts associated with such exposures is warranted.

This work is aimed to study the capabilities of CMAQ and WRF-Chem models for predicting the PM10 and PM2.5 pollution in the west side of Saudi Arabia. To do this fairly, one-month simulations (April, 2021) are done in both models using same initial and boundary conditions, meteorology and anthropogenic emissions. Unique configurations in both models allow to compare differences in the chemical processes and natural emissions estimation of each model. Simulated PM (PM10 and PM2.5) surface concentrations and AOD are compared with available observations to assess models’ performance. Moreover, CMAQ is used to study a real air pollution episode generated by a fire in the Rabigh Electricity Power Station between April 8 and April 11, 2021.

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