Background: Ambient air pollution is associated with adverse health effects, but the sources and components, which cause these effects is still incompletely understood. The aim of this thesis was to investigate the pulmonary effects of a variety of common air pollutants, including diesel exhaust, biomass smoke, and road tunnel and subway station environments. Healthy non-smoking volunteers were exposed in random order to the specific air pollutants and air/control, during intermittent exercise, followed by bronchoscopy. Methods and results: In study I, exposures were performed with diesel exhaust (DE) generated at transient engine load and air for 1 hour with bronchoscopy at 6 hours post-exposure. Immunohistochemical analyses of bronchial mucosal biopsies showed that DE exposure significantly increased the endothelial adhesion molecule expression of p-selectin and VCAM-1, together with increased bronchoalveolar lavage (BAL) eosinophils. In study II, the subjects were exposed for 1 hour to DE generated during idling with bronchoscopy at 6 hours. The bronchial mucosal biopsies showed significant increases in neutrophils, mast cells and lymphocytes together with bronchial wash neutrophils. Additionally, DE exposure significantly increased the nuclear translocation of the aryl hydrocarbon receptor (AhR) and phosphorylated c-jun in the bronchial epithelium. In contrast, the phase II enzyme NAD(P)H-quinone oxidoreductase 1 (NQO1) decreased after DE. In study III, the 2-hour exposures took place in a road tunnel with bronchoscopy 14 hours later. The road tunnel exposure significantly increased the total numbers of lymphocytes and alveolar macrophages in BAL, whereas NK cell and CD56+/T cell numbers significantly decreased. Additionally, the nuclear expression of phosphorylated c-jun in the bronchial epithelium was significantly increased after road tunnel exposure. In study IV, the subjects were exposed to metal-rich particulate aerosol for 2 hours at a subway station with bronchial biopsy and BAL sampling at 14 hours. The subway exposure significantly increased the concentration of glutathione disulphide (GSSG) in BAL, with no airway inflammatory responses. In contrast, the number of neutrophils in the bronchial mucosa and the nuclear expression of phosphorylated c-jun in the bronchial epithelium tended to decrease after the subway exposure. In study V, the exposure to biomass smoke lasted 3 hours. Bronchoscopy was conducted 24 hours post exposure. The investigated biomass combustion emissions resulted in a significant increase in total glutathione and reduced glutathione in BAL, without any evident acute airway inflammatory responses.     Conclusion: The present thesis presents data from exposures of healthy subjects to a variety of common air pollutants, as compared with an air reference. Oxidative as well as bronchial mucosal and bronchoalveolar responses differed between these air pollutants, with the most pronounced airway effects seen after exposure to diesel exhaust. This may be due to differences in pulmonary deposition, physicochemical characteristics, toxicological pathways and potency. Additional studies will assist in addressing dose-response and time kinetic aspects of the airway responses.

El impacto de la contaminación del aire es un tema crítico para el medioambiente y el clima. Una mala calidad del aire es un tema de importancia para la salud pública, especialmente en ambientes urbanos. El material particulado (PM), el ozono (O3) y el dióxido de nitrógeno (NO2) son los contaminantes más problemáticos en Europa y España. La Comisión Europea ha mostrado una gran preocupación por desarrollar técnicas que permitan incrementar el conocimiento sobre la dinámica de los contaminantes atmosféricos para asegurar el cumplimiento de la legislación y para informar a la población acerca de sus niveles. Además, la directiva europea 2008/50/CE establece la posibilidad de usar técnicas de modelización para informar sobre calidad del aire. Esta tesis doctoral está desarrollada en el marco de dos proyectos: El proyecto CALIOPE y el proyecto CICYT CGL2006-08903, ambos basados en la necesidad de desarrollar un sistema de calidad del aire que permita informar y entender los niveles de contaminación en Europa y España, con el objetivo de obtener un preciso pronóstico de la calidad del aire. Con ese propósito, el sistema de modelización CALIOPE se ha desarrollado con alta resolución espacial y temporal sobre Europa (12 km x 12 km y 15 capas, 1 hora), dominio madre, y España (4 km x 4 km y 15 capas, 1 hora), dominio anidado. CALIOPE consiste en un conjunto de modelos que tienen en cuenta la contaminación tanto antropogénica como natural. La disponibilidad del supercomputador MareNostrum, alojado en el Barcelona Supercomputer Center- Centro Nacional de Supercomputación, ha permitido trabajar a tan alta resolución. El objetivo principal de esta tesis es aumentar la confianza científica en el sistema CALIOPE, identificando sus puntos fuertes y débiles con un nivel de detalle que contribuya a establecer necesidades de mejora en el proceso de modelización. Por tanto, el presente trabajo ha evaluado espacial y temporalmente las simulaciones de calidad del aire sobre Europa y España en términos de O3, NO2, SO2, PM2.5 y PM10 en superficie sobre el año completo 2004. Para identificar el origen de las incertidumbres en la modelización del PM, su composición química ha sido también evaluada en ambos dominios. Las evaluaciones han sido realizadas sobre más de 150 estaciones de calidad del aire (más de 2 millones de datos experimentales). Además, esta tesis ha usado el sistema CALIOPE para analizar los patrones de calidad del aire sobre 2004, identificando claramente las áreas de contaminación. Las ideas más importantes que se desprenden de esta tesis son tres. Primero, las condiciones de contorno químicas basadas en un modelo global, como el LMDz-INCA2, son esenciales para modelizar el O3 troposférico sobre los dominios de estudio. Segundo, para simular la concentración de PM en el sur de Europa, tanto a escala rural como urbana, la contribución de polvo procedente del desierto del Sahara deber ser considerada debido a la proximidad al continente africano. La contribución del polvo del desierto a través del modelo BSC-DREAM8b ayuda satisfactoriamente a modelizar los picos de PM10 observados. Tercero, para ser capaz de modelizar la calidad del aire a escala urbana sobre España es esencial (1) una alta resolución espacial y temporal que permita describir fenómenos mesoescalares en áreas de topografía compleja , (2) un modelo de emisiones altamente desagregado como HERMES; (3) unos modelos que representen el estado actual del conocimiento en meteorología y química atmosférica / The impact of air pollution is a critical topic in environment and climate. Poor air quality is an important public health issue, especially in urban environments. Particulate matter (PM), tropospheric ozone (O3) and nitrogen dioxide (NO2) are the main problematic pollutants in Europe and Spain. The European Commission has shown a great concern for developing actions that allow increasing the knowledge on dynamics of atmospheric pollutants to assure the accomplishment of legislation and to inform the population about their levels. The European directive 2008/50/EC establishes the possibility of using modelling techniques to assess air quality. This Ph.D. thesis is developed in the framework of two projects: the CALIOPE project and the CGL2006-08903 CICYT project, both based on the necessity to develop an air quality modelling system that allows assessing and understanding the air pollution levels in Europe and Spain, with the aim of obtaining a precise air quality forecast. For that purpose, the CALIOPE air quality modelling system has been developed with high spatial and temporal resolution over Europe (12 km x 12 km, 1 h), as a mother domain; and Spain (4 km x 4 km, 1 h), as the nested domain. The CALIOPE system consists in a set of models that take into account both anthropogenic and natural pollution. The availability of the MareNostrum supercomputer, held in Barcelona Supercomputing Center- Centro Nacional de Supercomputación, has allowed such configuration of the CALIOPE system. The main objective of the present Ph.D. thesis is to increase the scientific confidence on the CALIOPE system, identifying skills and weakness with a degree of detail that contributes to establish necessities of improvements in the modelling process. Therefore, the present work has spatially and temporally evaluated CALIOPE air quality simulations over Europe and Spain in terms of O3, NO2, SO2, PM2.5, PM10 concentrations over the full year 2004. In order to identify the origin of uncertainties in PM modelling, PM chemical composition has been also evaluated in both target domains. Evaluations have been performed across more than 150 air quality-monitoring stations and over more than 2 million of experimental data. Furthermore, this Ph.D. thesis has used the CALIOPE system to assess air quality pattern over the year 2004, identifying clearly the areas of air pollution. There are three major thrusts of the present Ph.D. thesis. First, chemical boundary condition based on a global model, such as LMDz-INCA2, becomes essential to model O3 background concentrations in the target domains. Second, to simulate PM concentration in southern Europe, both regional and urban scales, the contribution of dust from the Saharan desert should be taken into account, since that region is frequently affected by dust outbreaks due to its proximity to the African continent. The contribution of desert dust through the BSC-DREAM8b helps to satisfactory model the observed episodic PM10 concentration peaks. Even more, the contribution of sea-salt aerosol is especially important over coastal areas. Third, to be able to model the air quality in urban scale over Spain it is essential (1) a high spatial (4 km x 4 km and 15 layers) and temporal (1h) resolution that allows describing mesoscale phenomena in very complex terrains; (2) a high disaggregated emission model to describe the sources, such as HERMES; and (3) an state-of-the-science meteorological and chemical models. This Ph.D. thesis has demonstrated that CALIOPE system applied over Europe and Spain is a useful tool which may contribute to (1) forecast air pollution in urban/suburban areas with a pervasive influence of anthropogenic emissions on a local scale and over very complex terrains and meteorology patterns; (2) assess about air pollution, discriminating between anthropogenic and natural episodes; and (3) manage air pollution, by means of modification of urban strategies or requirements of the legislation.

Introduction: Despite the known consequences of cigarette smoking, almost 20% of adults in the United States smoke. Smoking has been shown to harm nearly every organ of the body. Its detrimental effects have been seen not only in smokers themselves but also in those exposed to secondhand smoke (SHS) at work and in other public places. Methodology: The purpose of this thesis was to examine compliance with the signage requirement of the Georgia Smokefree Air Act (GSAA) of 2005 among 99 hospitality venues located in Atlanta. Photographs of bars and restaurant entrances were taken and raters then classified each venue as compliant or non-compliant with smoking status signage requirements of the GSAA. Additionally, air samples were collected using Sidepak equipment from 59 venues in order to estimate the PM2.5 levels, which is a recognized measure of air quality. With Spearman’s rho correlation coefficient (r), analyses were run to determine correlations between signage compliance, number of cigarettes being smoked, and smoking permitted with air quality (PM2.5). Analyses were conducted using the Statistical Package for Social Sciences (SPSS) version 19. Results: Of the 99 venues assessed, only 21 (21.2 %) complied with the signage requirements of the GSAA. Venues that do adhere to signage requirements and indicate no smoking on their signs and at the same time via telephone stated that smoking is prohibited had the lowest PM2.5 levels =15.03. On the contrary, those venues that display signs permitting smoking and via telephone indicated smoking is allowed had the highest PM2.5 levels =230.31. It was determined that there is a strong positive correlation between PM2.5 and “number of cigarettes” (r=.611, n=59, p<.001) as well as moderate correlation between PM2.5 and “smoking permitted” as indicated from phone calls (r=.464, n=59, p<.001). However, analysis showed a weak correlation between PM2.5 and “signage compliance” in accordance with GSAA (r=.107, n=59, p>.001). Conclusions: Enforcement of GSAA must be enhanced in order to better protect workers and patrons of Atlanta’s bars and restaurants from harmful exposure to SHS. Findings from this study support that prohibiting smoking in bars and restaurants and having signs stating that smoking is prohibited would improve air quality and protect workers by eliminating their exposure to SHS while working.

<p>In the first chapter of this dissertation, I outline a hedonic equilibrium model that explicitly controls for moving costs and forward-looking behavior. Hedonic equilibrium models allow researchers to recover willingness to pay for spatially delineated amenities by using the notion that individuals "vote with their feet." However, the hedonic literature and, more recently, the estimable Tiebout sorting model literature, has largely ignored both the costs associated with migration (financial and psychological), as well as the forward-looking behavior that individuals exercise in making location decisions. Each of these omissions could lead to biased estimates of willingness to pay. Building upon dynamic migration models from the labor literature, I estimate a fully dynamic model of individual migration at the national level. By employing a two-step estimation routine, I avoid the computational burden associated with the full recursive solution and can then include a richly-specified, realistic state space. With this model, I am able to perform non-market valuation exercises and learn about the spatial determinants of labor market outcomes in a dynamic setting. Including dynamics has a significant positive impact on the estimates of willingness to pay for air quality. In addition, I find that location-specific amenity values can explain important trends in observed migration patterns in the United States.</p><p>The second chapter of this dissertation describes a model which estimates willingness to pay for air quality using property value hedonics techniques. Since Rosen's seminal 1974 paper, property value hedonics has become commonplace in the non-market valuation of environmental amenities, despite a number of well-known methodological problems. In particular, recovery of the marginal willingness to pay function suffers from important endogeneity biases that are difficult to correct with instrumental variables procedures [Epple (1987)]. Bajari and Benkard (2005) propose a "preference inversion" procedure for recovering heterogeneous measures of marginal willingness to pay that avoids these problems. However, using cross-sectional data, their approach imposes unrealistic constraints on the elasticity of marginal willingness to pay. Following Bajari and Benkard's suggestion, I show how data describing repeat purchase decisions by individual home buyers can be used to relax these constraints. Using data on ozone pollution in the Bay Area of California, I find that endogeneity bias and flexibility in the shape of the marginal willingness to pay function are both important.</p><p>Finally, in the third chapter of this dissertation, I combine the insights of the Bajari-Benkard inversion approach employed in second chapter with more standard estimation techniques (i.e., Rosen (1974)) to arrive at a new hedonic methodology that allows for flexible and heterogeneous preferences while avoiding the endogeneity problems that plague the traditional Rosen two-stage model. Implementing this estimator using the Bay Area ozone data, I again find evidence of considerable heterogeneity and of endogeneity bias. In particular, I find that a one unit deterioration in air quality (measured in days in which ozone levels exceed the state standards) raises marginal willingness to pay by $145.18 per year. The canonical two-stage Rosen model finds, counter-intuitively, that this same change would reduce marginal willingness to pay by $94.24.</p> / Dissertation

Atmospheric particulate matter pollution is a challenging environmental concern in both urban and remote locations worldwide. It is intrinsically difficult to control, given numerous anthropogenic and natural sources (e.g. fossil fuel combustion, biomass burning, dust, and seaspray) and atmospheric transport up to thousands of kilometers after production. In urban regions, fine particulate matter (particles with diameters under 2.5 m) is of special concern for its ability to penetrate the human respiratory system and threaten cardiopulmonary health. A second major impact area is climate, with particulate matter altering Earth s radiative balance through scattering and absorbing solar radiation, modifying cloud properties, and reducing surface reflectivity after deposition in snow-covered regions. While atmospheric particulate matter has been generally well-characterized in populated areas of developed countries, particulate pollution in developing nations and remote regions is relatively unexplored. This thesis characterizes atmospheric particulate matter in locations that represent the extreme ends of the spectrum in terms of air pollution the rapidly-developing and heavily populated Pearl River Delta Region of China, the pristine and climate-sensitive Greenland Ice Sheet, and a remote site in the Colorado Rocky Mountains. In China, fine particles were studied through a year-long field campaign at seven sites surrounding the Pearl River Delta. Fine particulate matter was analyzed for chemical composition, regional variation, and meteorological impacts. On the Greenland Ice Sheet and in the Colorado Rocky Mountains, the carbonaceous fraction (organic and elemental carbon) of particulate matter was studied in the atmosphere and snow pack. Analyses included quantifying particulate chemical and optical properties, assessing atmospheric transport, and evaluating post-depositional processing of carbonaceous species in snow.

Burning joss paper and incense is a significant Taoist ceremonial practice in Asian countries such as Taiwan and China. The burning of joss paper has been demonstrated to significantly create particulate matters (PM) and to cause air pollution problems. PM in the atmosphere is among the primary air pollutants, and their sources are factories, vehicles, construction fields, combustion, vehicle exhaust dust, and aerosols derived from photochemical reactions. Numerous sources of environmental PM exist. Thus, the ability to rapidly determine the particulate type and source to adjust the controls and develop policies is an important issue for air quality management. This dissertation consists of two parts on the particulate emission control and characteristic identification. In the first part, we study investigates feasible options of air pollution control devices (APCD) for joss paper furnaces in temples, and used a 40 kg/hr joss paper furnace for testing. This paper examined particulate removal efficiencies of two options: a bag house (capacity 30 m3/min at 108 ¢J) and a wet scrubber (capacity 40 m3/min at 150 ¢J). The results indicate that PM in the diluted flue gas at the bag-house inlet were 76.6 ¡Ó 32.7 mg/Nm3 (average ¡Ó standard deviation), and those at the outlet of the bag-house could be reduced to as low as 0.55 ¡Ó 1.28 mg/Nm3. An average PM removal efficiency of 99.3 % could be obtained with a filtration speed of approximately 2.0 m/min evaluated at 108 ¢J. The wet scrubber removed approximately 70 % of PM, with scrubbing intensities higher than 4.0 L/m2.s across the scrubber cross-section. For the duration of the experiment, no visual white smoke (water mist) was observed at the exit of the wet scrubber with a combustion rate of 16 kg/hr of joss paper, and the scrubbing water temperature was automatically sustained at lower than 61 ¢J. The study concluded that both bag filtration and wet scrubbing are suitable techniques to control particulate emission from joss paper furnaces in Taiwanese temples. The bag filtration technique, while achieving higher efficiencies than the wet scrubbing technique, requires more space and cost. Examinations of bottom and fly ashes of combusted joss paper with X-ray diffraction (XRD) revealed the presence of calcium oxide in the fly ash, while certain metals were found in the bottom ash. The second part aimed at the investigates surface characteristics of airborne PM sampled from air pollution control devices of a number of industrial operations. The PM sources selected for this study comprise the following operations or processes: a coke oven, iron ore sintering furnace, blast furnace, and basic oxygen furnace from an integrated steelmaking plant; electric arc furnaces of two secondary steelmaking plants; a municipal solids waste incinerator; two oil-fired boilers; and a coal-fired power plant boiler. The collected PM samples were analyzed using a scanning electronic microscope (SEM) and energy-dispersive X-ray spectroscope (EDS) to determine their chemical composition and surface characteristics. Results for each PM sample regarding size, surface characteristics, and chemical compositions can be used to trace the related emission industrial sources.

Steel industry is a highly polluted industry and one of the most important stationary sources in Kaohsiung City. The steel manufacturing process could emit a huge amount of particles, such as the sintering process, the blast furnace operation, and the raw material handling process. Suspended particles emitted from steel industry could deteriorate ambient air quality and cause adverse effects on human health. In order to understand the impact of steel industry on ambient air quality in Siaogang District and to identify potential pollution sources, this study selected a integrated steel manufacturing plant located at Siaogang District to conduct a sampling protocol of suspended particulate matter (PM) at ambient sites (A1~A5) and sensitive sites (S1~S5) from July 2011 to March 2012. The size distribution of suspended particles in four seasons was measured with PM10 high-volume samplers, dichotomous samplers, and MOUDI for 3 days (24 hours for single sampling), and dustfall samplers for one month, to investigate the spatial distribution and temporal variation of PM concentration. After sampling, the physicochemical properties of PM, including mass concentration, particle size distribution, dustfall concentration, water-soluble ionic species, metallic elements, and carbonaceous contents, were further analyzed. Field measurement of ambient PM showed that the averaged ambient PM10 concentration (53.54 - 203.56 £gg/m3) were higher than sensitive sites (55.06 - 140.07 £gg/m3) and the averaged ambient PM2.5 concentration of ambient (23.10 - 120.21£gg/m3) were higher than sensitive sites (12.52 - 65.62 £gg/m3). No matter ambient or sensitive sites, it showed a tendency of lower concentration in summer, indicating that concentration variation of PM10 and PM2.5 were highly affected by meteorological factors (such as wind direction, wind speed, and relative humidity) in Siaogang District. Furthermore, a t-test result showed that ambient and sensitive sites have similar pollution sources since the p-values were in significantly different. Chemical analysis of PM results showed that the most abundant water-soluble ionic species of PM at the ambient and sensitive sites were secondary inorganic aerosols (SO42-, NO3-, and NH4+) and [NO3-]/[SO42-] showed that ionic species were mainly emitted from stationary sources. Fe, Al, K and Ca were the major metallic elements of this study, and the major pollution sources contain industries, traffics, and road dusts. Additionally, the raw material handling process was the major pollution source of PM. Correlation analysis of OC and EC showed that PM at ambient and sensitive sites were originated from primary sources, such as vehicles, industries, road dusts, and human activities. Results obtained from PCA and CMB receptor modeling showed that both PM2.5 and PM10 highly correlated with wind direction in different season and the major pollution sources were industry pollution (including petroleum refineries, power plants, waste incinerators, consistent operating steel mills and electric arc furnace steel mills, etc.), followed by local traffics and derivative. Furthermore, marine aerosols were one of the important pollution sources at sensitive sites (S1, S4, and S5) where close to the ocean.

Particulate matter (PM) concentrations in ambient air can be monitored by gravimetric sampling near a source using Federal Reference Method (FRM) samplers. PM is regulated by size, with PM10, which is comprised of particles with aerodynamic equivalent diameters less than or equal to 10 μm, being the main focus of this research. FRM PM10 samplers exhibit sampling errors when sampling dusts with mass median diameters (MMDs) that are larger than the 10 μm sampler cutpoint. For industries to be regulated equitably, these sampler errors must be quantified and understood. This research evaluates the performance of FRM PM10 and low volume total suspended particulate (TSP) samplers under the controlled conditions of a wind tunnel. The performance evaluation was conducted by observing the sampler cutpoints, slopes, and measured concentrations. These measured values were compared to values obtained using a collocated isokinetic reference sampler. The results of this research indicate that PM10 samplers do not operate as intended under all conditions. The cutpoint of the PM10 inlets was significantly higher than the maximum FRM limit of 10.5 μm when sampling dust with MMDs larger than the cutpoint of the sampler. The slope values for the PM10 inlets were significantly higher than the maximum FRM limit of 1.6. MMDs and geometric standard deviations of PM collected by TSP samplers were significantly different than those of PM collected using the collocated isokinetic sampler. The concentrations measured by the TSP samplers were significantly higher than the collocated isokinetic sampler. The results of this research provide a better understanding of the performance of TSP and PM10 samplers operating under different conditions and shows that these samplers are not operating as intended. Because of this, industries may be suffering the consequences of inequitable regulation.

The objective of this study was to investigate the exposure assessment and health risk of particulate matter emitted from steel industry for high-risk inhabitants living in metro Kaohsiung. A steel plant and an electric arc plant were selected for conducting the sampling of particulate matter (PM). The physical and chemical properties of PM sampled at the working place and at the fence of selected plants were also analyzed to establish the fingerprints of PM in the steel industry. In order to accomplish this study, both personal sampling and environmental sampling were conducted in steel plants. Personal exposure sampling was undertaken at working places, while the conduction of environmental sampling might affected by various uncertain environmental factors (such as meteorological condition and other emission sources), but it could characterize the overall environmental situation and help exposure assessment. Moreover, The exposure of employers (including manufacturing workers and supporting staffs) could be further assessed based on the concentration and duration of PM exposure. Specific metal concentration was obtained from working environment, searching for exposure parameter (such as exposure frequency, exposure duration, body weight, average time, and etc.) and toxicity database (e.g. cancer slope factor and reference dose). The data could be used for assessing both cancer risk and non-cancer risk of specific heavy metal. Sampling data obtained from working places showed that the highest PM concentration were observed during the electric arc process, especially the charging and discharging procedures. The concentration of PM1.0, PM10, and TSP at the working places were 53.3~195.6 £gg/m3 ,365.7~550.0 £gg/m3, and 1085.5~2755.0 £gg/m3, respectively. Measured at the outdoor environments of working places, the highest PM10 and TSP concentration, ranging from 365.7~550.0 £gg/m3 and 1085.5 ~2755.0 £gg/m3, were observed at the sinter plants of a steel manufacturer. Sampling data obtained at the fence of steel plants (a steel plant and electric arc plant) indicated that the concentration of PM10 and TSP exceeded the ambient air quality standards. Modification of manufacturing process and improvement of PM collection system are highly required to reduce the concentration level as well as the emission of PM. Results of fingerprint of PM (PM2.5, PM2.5-10, TSP) obtained from working places showed that iron, calcium, sulfate, nitrate, calcium ion, and elemental carbon were the major chemical content of PM at the melting plant, the sinter plant, and the storage field. While, iron, calcium, sulfate, nitrate, calcium ion, and organic carbon were the major chemical content of PM at electric arc plant. Results of personal exposure concentration and exposure dose of PM showed that the highest exposure level of both manufacturing workers and supporting staffs were observed at the storage field, while the lowest exposure level was found at the sinter plant. Therefore, enforcement of wearing maskers and/or shelters at the storage field is also highly recommended to prevent manufacturing workers from the exposure of high-level PM at working places. Moreover, the cancer risk of manufacturing workers exposured to hexavalent chromium (Cr6+) at the melting plant, the sinter plant, the storage field, and the electric arc plant exceeded acceptable cancer risk standard (10-5~10-6), while the hazard index of manganese (Mn) was much higher than other metals.Meanwhile, exposuring to Cr6+, Ni, and Mn at the electric arc plant also exceeded acceptable standards (Cr6+ and Ni¡G10-5~10-6 , Mn¡G1). Several control strategies, including pollution reduction measures such as the usage of clean fuel, process modification, the improvement of collection system, the enhancement of manufacture management, the conduction of environmental monitoring and exposure assessment, floor cleanup and truck entrance management, are recommended to improve the contamination of PM at working places and surrounding environments for metallurgic industries. Moreover, enforcement of wearing maskers and/or shelters at high-risk environments is also highly recommended to prevent manufacturing workers from the exposure of high-level PM at working places. Keywords: steel industry, particulate matter sampling, physical and chemical characteristics, exposure assessment, health risk

An engineering analysis of the fugitive particulate matter emissions from a feedyard is not simple. The presence of an evening dust peak in concentration measurements downwind of a feedyard complicates the calculation of an average 24-h emission flux for the feedyard. The evening dust peak is a recurring event that occurs during evening hours when particulate matter concentration measurements increase and decrease dramatically during a short period of time. The concentrations measured during the evening can be up to 8 times the concentrations measured throughout the rest of the day. There is a perception that these concentration increases are due to increases in cattle activity as the temperature decreases during the evening. The purpose of Objective 1 of this research was to quantify the changes in concentrations based on changes in meteorological conditions and/or cattle activity. Using ISCST3, a Gaussian-based EPAapproved dispersion model used to predict concentrations downwind of the feedyard , the results of this work indicate that up to 80% of the increase in concentrations can be attributed to changes in meteorological conditions (wind speed, stability class, and mixing height.)The total fugitive particulate matter emissions on a cattle feedyard are due to two sources: unpaved roads (vehicle traffic) and pen surfaces (cattle activity). Objective 2 of this research was to quantify the mass fraction of the concentration measurements that was due to unpaved road emissions (vehicle traffic). A recent finding by Wanjura et al. (2004) reported that as much as 80% of the concentrations measured after a rain event were due to unpaved road emissions. An engineering analysis of the potential of the unpaved road emissions versus the total feedyard emissions using ISCST3 suggests that it is possible for 70 to 80% of the concentration measurements to be attributed to unpaved road emissions. The purpose of Objective 3 was to demonstrate the science used by ISCST3 to predict concentrations downwind of an area source. Results from this study indicate that the ISCST3 model utilizes a form of the Gaussian line source algorithm to predict concentrations downwind of an area source.