Passive samplers are subject to a myriad of sources of uncertainty, which affect their precision and accuracy. To investigate this uncertainty, an evaluation of passive sampler data for SO2, NO2, O3, and H2S was carried out in the Lakeland Industry & Community Association in east-central Alberta from 2009 – 2011. The results of this study indicate that while passive sampler data followed the same general trend as continuous monitoring data, passive sampler data were often statistically different which strongly indicates they were not always accurate. Passive samplers are further limited by only providing a time weighted average of pollutant concentrations over the sampling period, which prevents determination of when or where a pollutant has exceeded regulatory limits. While passive samplers are useful in monitoring general changes in ambient air quality at low concentrations, this work strongly suggests that passive sampler data should not be used for regulatory monitoring.

Mercury is a pervasive environmental contaminant which is globally distributed in freshwater ecosystems. In order to assess the risk that mercury and methylmercury pose to public health through consumption and trophic level transfer, it is first necessary to understand the interactions and uptake that occurs between benthic organisms and mercury impacted sediments. Delineation of these interactions currently rely on correlating measurements of bulk sediment concentrations with bioaccumulation of either total mercury or methylmercury. However, it has been proposed that porewater concentrations, rather than sediment concentrations, should be used to predict uptake and bioavailability. Diffusive gradient in thin films (DGTs) have been proposed as a viable technique for porewater measurements to assess the bioavailable fractions of mercury. DGTs were compared to traditional bulk solid sampling to assess their capabilities for the prediction of total and methylmercury bioaccumulation in benthic oligochaetes, T. tubifex. DGTs performed similarly to the bulk solids sampling approach in respect to their correlation with mercury bioaccumulation in the sediment matrix studied. Bioturbation was shown to impact redox profiles in the sediment which led to a decrease in porewater methylmercury concentrations in the uppermost surficial sediment depths. These results indicate that monitoring tools such as DGTs are necessary to better understand the fate of mercury at field scale contaminated sites. / text

Volatile organic compounds (VOCs) are those chemical species having sufficiently high vapor pressures to exist largely or entirely in the gaseous phase, whereas reactive organic carbon (ROC) encompasses all organics except methane. ROC can be emitted biogenically and anthropogenically, usually in a pure hydrocarbon form that is susceptible to reaction with common atmospheric oxidants such as hydroxyl and ozone in the initial steps to the formation of particulate matter, the criteria pollutant most strongly implicated in human mortality. The diversity of both the emitted VOCs and their possible atmospheric reactions yields countless different compounds existing in the atmosphere with a correspondingly wide range of volatility, solubility, reactivity, etc.. Moreover, the temporal and spatial variability of a given analyte is often large. Real-time chemical characterization of gaseous and particulate organic compounds can be achieved by instrumentation utilizing chromatographic and/or mass spectrometric techniques, but these methods are expensive, often logistically challenging, and require high levels of skills for both operation and data analysis. Conversely, filter-based measurements for organic particulates are inexpensive and straightforward, but do not give real-time data and analytes may be lost or transformed before analysis. There is a niche for robust, low-maintenance, moderate-cost instrumentation that offers chemical information on atmospheric carbon. Presented here are two projects that develop and validate instrumentation for measuring ROC. The first combines flame ionization detection (FID) with a CO2 detector to estimate the O/C ratios of sampled gases and particulates. O/C ratios are a particularly valuable piece of chemical information as higher ratios give lower volatility and higher solubility, meaning increased propensity to partition into the condensed phase. The second project utilizes portable VOC samplers with sorbent tubes that trap and protect analytes for detailed analysis. The samplers' portability and programmable microcontrollers offers the investigator great flexibility, both spatially and temporally. A third project analyzed the chemical composition of commercially available fragrance mixtures and modeled their emissions' impact on oxidant reactivity. It was observed that terpenes, despite their low mole fractions in the mixtures, represent the vast majority of emitted reactivity and are quantitatively evolved from the mixtures in a matter of hours. / Doctor of Philosophy / Organic (i.e., carbon-containing) compounds are emitted into the atmosphere from a variety of natural and anthropogenic sources. Respective examples would include the agreeable aroma of a pine forest (from terpene compounds) or the pungent smell of gasoline (from additives such as toluene). These emitted compounds are often pure hydrocarbons (molecules formed of carbon and hydrogen atoms), and the category VOCs (volatile organic compound) encompasses hydrocarbons and the products of their chemical reactions with atmospheric oxidants like the hydroxyl radical and ozone. In the presence of pollutant nitrogen oxides, oxidants modify these VOCs; adding oxygen lowers the VOCs' vapor pressure and increases aqueous solubility, resulting in higher likelihood of condensation from the gaseous phase into particulates (liquid or solid phases). "Smog" is a colloquial term for the entire suite of noxious chemical compounds produced in the air from reactions of largely anthropogenic organic precursors. Particulates, a.k.a. aerosols, are the most concerning atmospheric pollutant due to deleterious effects on respiratory and cardiovascular health and has shown strong correlations with increased mortality in exposed groups such city dwellers. Determining the chemical identities of the VOCs is useful for pollution forecasting and possibly identifying and quantifying VOC sources. Current methods for chemical identification are cumbersome, expensive, complex, and wholly unsuitable for many investigators. In this work, we introduce two new approaches to gathering chemical information about organic gases and particulates. The first instrument has been demonstrated to give accurate estimates of oxygen/carbon (O/C) ratios; higher O/C ratios represent higher propensities to condense into particulate forms. The second instrument developed is a portable VOC sampler, which traps (and prevents reaction of) a broad range of organics on a sorbent (such as activated charcoal) in a small metal tube. After sampling in remote locales, the tubes can be analyzed in the lab and the VOCs identified and quantified. The third study investigated the chemical composition of fragrance mixtures (present in perfumes, cleaning agents, etc.) and modeled (i.e., estimated) VOC emissions based on the fragrance components as well as the effects on atmospheric oxidant levels. Fragrance mixtures represent a significant source of atmospheric carbon, so a more thorough understanding of the fragrances' impacts on oxidant levels gives further insight into atmospheric processes and aerosol formation.

The aim of this thesis is to analyze and evaluate temporal and spatial patterns of concentrations of ambient ozone in the CHKO Jizerské hory. The Jizerské hory Mts. are an area where one of the highest concentrations of ambient ozone are measured every year and, therefore, our attention was focused on this area. The measurements were carried out between 2006 and 2010 at 13 sites (714-1000 m n. m.) in the CHKO Jizerské hory. From the input data, which were fortnightly average nitrate concentrations created on the filters of Ogawa passive samplers, fortnightly average concentrations of ambient ozone were computed using the empirical flow. Ambient ozone concentrations ranged from 13,8 ppb (year 2007) to 72,1 ppb (year 2006). From the five-year period under study defy the year 2006, when the highest concentrations of ambient ozone were measured. The lowest concentrations occurred in 2009. In all years, the concentrations of ambient ozone increased with increasing elevation and this gradient ranged from 2,7 to 4,6 ppb on 100 meters altitude. The accuracy and precision of measurement was very good (accuracy: R2 = 82 %; precision: R2 = 98 %). By multiple linear regression it was found, that ambient ozone concentration are influenced, in addition to the altitude, by ozone concentrations from previous...

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 44-47)

In October 1852, Amy Fiske (1785-1859) of Sturbridge, Massachusetts, stitched a sampler. But she was not a schoolgirl making a sampler to learn her letters. Instead, as she explained: “The above is what I have taken from my sampler that I wrought when I was nine years old. It was w[rough]t on fine cloth it tattered to pieces. My age at this time is 66 years.” Drawing from 167 examples of decorative needlework – primarily samplers and quilts from 114 collections across the United States – made by individual women aged forty years and over between 1820 and 1860, this dissertation explores how Fiske and women like her experienced social and cultural change in antebellum America, and probes their personal reactions to growing older. Falling at the intersection of women’s history, material culture study and the history of aging, this dissertation brings together objects, diaries, letters, portraits, and prescriptive literature to consider how middle-class American women experienced the aging process. Chapter 1 explores the physical and mental effects of “old age” on antebellum women and their needlework. It considers samplers modified later in life through the removal of the maker’s age or the date when the sampler was made. Chapter 2 examines epistolary needlework, that which relates a message or story in the form of stitched words. Chapter 3 focuses on technological developments related to needlework during the antebellum period, particularly indelible ink and the rise of the sewing machine, and the tensions that arose from the increased mechanization of textile production. Chapter 4 considers how gift needlework functioned among friends and family members. The materials, style and techniques represented in these gifts often passed along an embedded message, allowing the maker to share her opinions, to demonstrate her skill and creativity, and to leave behind a memorial of her life. Far from being a decorative ornament or a functional household textile, these samplers and quilts served their own ends. They offered aging women a means of coping, of sharing and of expressing themselves. In the end, the study argues that these “threads of time” provide a valuable and revealing source on the lives of mature antebellum women.

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State Air Pollution Regulation Agencies (SAPRAs) issue and enforce permits that limit particulate matter emissions from all sources including layer and broiler facilities, cattle feedyards, dairies, cotton gins, and grain elevators. In this research, a process was developed to determine distances from emitting sources to where the estimated concentrations were less than the National Ambient Air Quality Standards (NAAQS). These distances are a function of emission rates and meteorological conditions. Different protocols were used to develop emission factors for cattle feedyards and layer houses. Dispersion modeling with American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was conducted to determine the emissions of particulate matter. These data were used to determine the distances from the sources to where the concentrations of particulate matter (PM) would be less than the NAAQS. The current air-permitting process requires that concentrations from a source do not exceed the NAAQS at the property line and beyond for the facility to be in compliance with its permit conditions. Emission factors for particulate matter less than 10 micrometers (PM10) were developed for cattle feedyards using a reverse modeling protocol and Tapered Element Oscillating Microbalance (TEOM) sampler data. Corrections were applied to the TEOM measurements to account for TEOM vs. filter-based low-volume (FBLV) sampler bias and over-sampling of PM10 pre-collectors. Invalid concentrations and dust peaks larger than mean ± 3 times the standard deviation were excluded from this study. AERMOD predictions of downwind concentrations at cotton gins were observed for compliance with 24-hour PM10 and PM2.5 NAAQS at property lines. The emissions from three cotton gins were analyzed at 50 m and 100 m distances. TEOM and FBLV samplers were used to collect 24-hour PM10 measurements inside a laying hen house. The distances to the property lines at which the emissions of PM10 were below the 24-hour average PM10 standards were estimated using AERMOD. The results suggested that the special use of the NAAQS for as the property-line concentration not to be exceeded, could be problematic to agriculture. Emission factors that were comparable of published emission factors were obtained in this study. Large distances to property lines were required when minimum flow rate recommendations were not considered. Emission factors that are representative of the emissions in a particular facility are essential; else facilities could be inappropriately regulated.

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Made available in DSpace on 2015-04-22T22:01:54Z (GMT). No. of bitstreams: 1 Najara Marinho de Assis.pdf: 4136541 bytes, checksum: e841bade3c95236a92cf25313bf4398e (MD5) Previous issue date: 2007-06-30 / Fundação de Amparo à Pesquisa do Estado do Amazonas / Nitrogen Dioxide (NO2) is a toxic gas and contributed to the environmental impact. This work showed an evaluation of the levels and distribution of NO2 in Manaus by passive technique of sampling. Twenty points were distributed in strategic points in the city. The NO2 varied from 4,56 ± 1,29 to 22,48 ± 3,91 μg m-3 in 2006. The largest values were found at places of great flow of vehicles. The minimum value were found at Marina Tauá (place with little urban influence). The method detection limit observed was (0,37 ± 0,26 μg m-3). / Dióxido de nitrogênio (NO2) é um gás tóxico e contribui para o desequilíbrio ambiental. Neste trabalho fez-se uma avaliação dos níveis e distribuição de NO2 em Manaus usando técnica passiva de amostragem. Vinte pontos foram distribuídos de maneira estratégica na cidade. Os níveis médios de NO2 encontrados variaram de 5,0 ± 1,0 a 23,5 ± 4,0 μg m-3 de NO2 no ano de 2006, sendo os maiores valores encontrados em locais de grande fluxo de veículos. O valor mínimo representa a região da Marina Tauá (referência de pouca influência urbana). O limite de detecção para o método usado foi de (0,4 ± 0,3) μg m-3.