Thesis (Ph.D.)--Drexel University, 2010. / Includes abstract and vita. Includes bibliographical references (leaves 212-224).

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 233-246). Also available in electronic version.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed June 30, 2007). Includes bibliographical references (p. 94-101).

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The contributions of specific polluting sources to both indoor and outdoor atmospheric pollution are difficult to determine, as solid and gaseous products from different combustion sources are often similar. Sometimes, however, a marker compound can be identified that is unique to a pollution source (or at least not present in most other local combustion sources) and which will allow assessment of the contribution of that source to total atmospheric pollution. The aim of this study was to identify suitable marker compounds and methods for the apportionment (assessment of percentage contribution) of specific sources to atmospheric pollution. The sources selected were diesel exhaust emissions in outdoor, and environmental tobacco smoke (ETS) in indoor environments. Studies with controlled (laboratory) atmospheres would be followed by field studies using these methods and markers to produce apportionments for these sources to air pollution in selected environments. Initial analysis of such polluting sources was therefore the qualitative analysis of volatile compounds and particulate associated material, both organic and inorganic. Volatile organic compounds were adsorbed onto various resins, while particulate material was sampled onto various filter paper types. Organics were determined by GC-AED and GC-MS, and elements by ICP-MS.1-Nitropyrene was identified as a suitable marker for diesel particulate emissions (< 5um). A large volume air sample from Sheffield city centre using 1-nitropyrene as a marker suggested that 63% of atmospheric particulate material (< 5um) might be of diesel origin. However the concentration of 1-nitropyrene is low in atmospheric samples, and in the volumes used in routine sampling the amount of 1-nitropyrene was below the limit of detection on the instrument used. In an alternative approach the aliphatic alkane tetracosane (C24) was used as a diesel marker for urban air, with a 1-nitropyrene:tetracosane ratio derived from the average results from laboratory experiments with a diesel engine running at various speeds and loads. This approach yielded apportionment values ranging from 5-85% for the diesel contribution to particulate material (< 5mum) in the urban air of Sheffield. No volatile marker compound was found for diesel apportionment. The contribution of ETS to atmospheric pollution has previously been estimated from the measurement of respirable suspended particulates (RSP), which was superseded by total UV absorbance and total fluorescence of a methanol extract. More recent work has suggested the use of solanesol or scopoletin as marker compounds. This thesis shows that the non specific methods overestimated the particulate contribution of ETS in some atmospheres, and that solanesol is a better marker compound than scopoletin. Preliminary studies from a small number of smokers homes and offices, with solanesol as a marker compound for particulate ETS, indicated that ETS contributions to total particulate material (< 5mum) ranged from 6 to 49% in homes and 11 to 28% in offices. Pyrrole was used as a marker for ETS contribution to volatile organic pollution, and studies with controlled atmospheres with a smoking machine allowed calculation of the ratios of pyrrole to other volatile organic compounds (VOC's) in ETS. Samples from the field study were used to produce apportionment percentage levels of benzene, toluene, o-xylene and p+m-xylene associated with ETS.In addition the use of tree bark as a atmospheric sink for airborne particulates was investigated. Six nitrated polycyclic aromatic hydrocarbons associated with diesel emissions were quantified in bark extracts and levels of these were found to be highest during winter months.

As part of the Avon Longitudinal Study of Pregnancy And Childhood, the toxic metal, mercury, is studied in order to assess whether it presents a danger to the development of children in the UK.The development and optimisation of a digestion procedure for the determination of total mercury in hair is described. The procedure chosen consists of the microwave digestion of 0.2-0.5g hair with 2 ml HNO3 and 1 ml H2O2 . The effect of washing and drying of the samples is investigated, and found not to influence analytical results when hair samples are collected after shampooing. However, freeze-drying of the samples results in the loss of 30% of mercury. The distribution of mercury along the length of a strand of hair is studied. It is shown to vary in adults (up to a factor of 7) but not in children (less than 20%). In the applications of this analytical method to population studies, the frequency of fish meals, and the age of the subject are positively correlated to the mercury levels in adults' hair (r = 0.539 and 0.513, respectively). Breast-feeding and mercury levels in children's hair are also correlated (r = 0.433). The relationship between number of fillings and mercury levels in adults' hair is not significant. No correlation was found between mercury levels in children's hair and Developmental Quotient (Griffith's scales) (r = -0.24 to 0.18).The optimisation of a coupled High Performance Liquid Chromatography - CV-AFS system for the study of mercury speciation is described. The use of KOH and microwave digestion for the extraction of mercury species was unsuccessful, and thus recommendations for future work are made.

abstract: The following research is a regulatory and emissions analysis of collocated sources of air pollution as they relate to the definition of "major, stationary, sources", if their emissions were amalgamated. The emitting sources chosen for this study are seven facilities located in a single, aggregate mining pit, along the Aqua Fria riverbed in Sun City, Arizona. The sources in question consist of Rock Crushing and Screening plants, Hot Mix Asphalt plants, and Concrete Batch plants. Generally, individual facilities with emissions of a criteria air pollutant over 100 tons per year or 70 tons per year for PM10 in the Maricopa County non-attainment area would be required to operate under a different permitting regime than those with emissions less than stated above. In addition, facility's that emit over 25 tons per year or 150 pounds per hour of NOx would trigger Maricopa County Best Available Control Technology (BACT) and would be required to install more stringent pollution controls. However, in order to circumvent the more stringent permitting requirements, some facilities have "collocated" in order to escape having their emissions calculated as single source, while operating as a single, production entity. The results of this study indicate that the sources analyzed do not collectively emit major source levels of emissions; however, they do trigger year and daily BACT for NOx. It was also discovered that lack of grid power contributes to the use of generators, which is the main source of emissions. Therefore, if grid electricity was introduced in outlying areas of Maricopa County, facilities could significantly reduce the use of generator power; thereby, reducing pollutants associated with generator use. / Dissertation/Thesis / M.S.Tech Technology 2011

BACKGROUND: Exposures to air pollution has been associated with lower conception and fertility rates. However, the impact of pollution on infertility is unknown. OBJECTIVES: To examine the associations of roadway proximity (a measure of traffic exposure) and particulate matter (PM) air pollution and incidence of infertility. METHODS: Proximity to major roadways and ambient exposures to particulate matter less than 10 microns (PM10), between 2.5 and 10 microns (PM2.5-10), and less than 2.5 microns (PM2.5) were determined for all residential addresses for 36,294 members of the prospective Nurses' Health Study II cohort from 1993 to 2003. Infertility was defined by report of attempted conception for ≥12 months without success. Participants were able to report if evaluation was sought and if so, offer multiple clinical indications for infertility. Multivariable adjusted Cox proportional hazard models were used to estimate the relation between each exposure and infertility risk. RESULTS: Over 213,416 person-years, there were 2,508 incident reports of infertility. Results for overall infertility were inconsistent across exposure types. We observed a small increased risk in those living closer to compared to farther from a major road, multivariable adjusted hazard ratio (HR)=1.11(95% confidence interval (CI) = 1.02-1.20). Among those reporting primary infertility, risk was greater with closer distance to road and for all PM size fractions and exposure time windows. The multivariable adjusted HR (95%CI) for women living closer to compared to farther from a major road for primary infertility was 1.37 (1.22-1.52), while for secondary infertility HR=1.07 (0.95-1.21). In addition, the HR for every 10 mcg increase in cumulative PM2.5 among women with primary infertility was 1.61 (1.35-1.92), while it was 1.1 (0.91-1.33) for those with secondary infertility. CONCLUSIONS: This study suggests exposures to traffic and PM may be associated with a small increased risk of infertility, especially primary infertility.

Exposure to pollutants of ambient origin contributes significantly to the global disease burden (Cohen et al., 2017). Mounting evidence has demonstrated disproportionately high ambient PM2.5 and NO2 concentrations in the U.S. among nonwhite and low-income populations, potentially contributing to environmental health disparities (Bell and Ebisu, 2012; Clark et al., 2014; Morello-Frosch and Lopez, 2006). There is limited understanding of temporal trends and underlying causes of exposure inequalities (EIs), and whether residential building characteristics modify observed EIs. Further, while ambient pollutants have been linked to cardiometabolic disease in adulthood, few studies have documented the link between early-life ambient air pollution exposure and weight growth trajectories in early childhood- an informative step on the causal pathway between early life exposures and chronic outcomes. Using 1 km2 PM2.5 and NO2 predictions in Massachusetts and Census data, we quantify longitudinal EI between sociodemographic groups over a decade. We estimate AER for all Massachusetts residential parcels using publicly available data and assess whether accounting for AER exacerbates or ameliorates PM2.5 inequalities. We examine associations of weight growth trajectories in early childhood with residential prenatal and postnatal PM2.5 and distance to road (traffic) exposure in the Boston-based Children’s HealthWatch cohort. PM2.5 and NO2 inequalities increased across the study period in urban areas, and EIs were more pronounced for NO2 than PM2.5 and among racial/ethnic groups compared to other population subgroups. Analyzing EI longitudinally revealed that spatio-temporal shifts in air pollution, and not demographic distributions, contributed to exposure disparities. We found substantial variability in estimated AER across the state, and that PM2.5 EIs were magnified when AER was considered. Prenatal PM2.5 >9.5 µg/m3 predicted higher weight growth rates among females, but with an opposite direction of effect in males. This association was modified by birth weight and AER, with a stronger magnitude of effect in low-birthweight and higher-AER females. These findings underscore the importance of considering vulnerable communities and residential characteristics in ambient air pollution reduction strategies. This dissertation provides an opportunity to understand susceptible phenotypes and periods of potential intervention to reduce ambient air pollution impacts on cardiometabolic outcomes. / 2020-03-17T00:00:00Z

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