Fumes emitted from coffee bean roasters contain various chemicals such as aldehydes, pyridine, volatile fatty acids, and ketones. These chemicals have high odor intensities and are sensitive to human breathing organs and eyes. In Taiwan, most of these fumes are not well controlled before venting to the atmosphere. This research attempted to eliminate these odorous and offensive chemicals by chemical scrubbing methods. Sodium hypochlorite oxidation followed by hydrogen peroxide reduction (hypochlorite-peroxide) was investigated first. After that, ozone oxidation followed by hydrogen peroxide reduction (ozone-peroxide) was also tried. In both methods, hydrogen peroxide acted as a reducing agent for the elimination of either residual chlorine or ozone emitted from the oxidation reaction. Experimental results indicated that both methods were effective. An oxidative scrubbing liquid with an initial effective chlorine content of 200 mg/L and a pH of 12, and an reducing scrubbing liquid with an initial hydrogen peroxide concentration of 1% and a pH of 12 could remove an average of 85% of total hydrogen carbons (THC) in the fume gas from a coffee bean roaster. With a dose of 10 ppm ozone in the fume gas to the oxidative scrubbing liquid (water only) followed by an reducing scrubbing liquid with an initial hydrogen peroxide concentration of 0.3% and a pH of 12, an average removal of 80% of the THC could be removed. An odor intensity (expressed by the dilution to threshold ratio) of 9,772 in the original fume could be reduced to as low as 31 by both methods. As indicated by the data from GC/MS (gas chromatography-mass spectrometry) analysis for the hypochlorite-peroxide method, acrolein, vinyl acetate, 2-butanone, and acetone in the roaster fume could almost completely be eliminated. Traces of chlorinated hydrocarbons as potential secondary pollutants were detected in the treated gases from the hypochlorite-peroxide scrubbing system. While by the ozone-peroxide one, satisfactory results were also obtained with no chlorinated hydrocarbons emitted. An economical analysis shows that the ozone-peroxide approach is a practical one for actual control applications.

Thesis (Ph. D.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 148 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical reference.

Poor sleep quality is an important symptom of many medical or psychiatric disorders. However, the impact of cooking oil fumes (COFs) on sleep quality has not been studied. This population-based cross-sectional study was conducted to examine the association between COFs of Chinese household cooking and sleep quality. Individual sleep quality assessment was completed in 2197 participants with an average age of 37.52 years, through Pittsburgh Sleep Quality Index (PSQI). Information about their cooking practice were also collected by self-reported questionnaire. As an internal biomarker of COFs, urinary 1-hydroxypyrene (1-HOP) (n = 562) was further measured using high-performance liquid chromatography. Binary logistic regression models were performed to evaluate the association between exposure to COFs and individual sleep quality. We found that, subjective poor kitchen ventilation, preheating oil to smoking, and cooking for over 30 minutes were positively associated with overall poor sleep quality (global PSQI score >5) [odds ratio (OR) = 1.75, 95% confidence interval (CI) = 1.43–2.16; 1.25, (1.03–1.52); 1.42, (1.15–1.76), respectively]. After adjusting for potential confounders, subjective poor kitchen ventilation still tend to increase the risk of long sleep latency, sleep disturbances, and daytime dysfunction [OR = 1.37, 95% CI = 1.09–1.73; 1.91, (1.39–2.61); 1.54, (1.23–1.93), respectively]. Similar results were observed in participants who preheated oil to smoking [OR = 1.36, 95% CI = 1.08–1.72; 1.55, (1.14–2.14); 1.25, (1.02–1.55), respectively] and cooked for over 30 minutes [OR = 1.34, 95% CI = 1.05–1.72; 1.46, (1.03–2.06); 1.36, (1.08–1.72), respectively]. Furthermore, high urinary 1-HOP level was also positively associated with overall poor sleep quality (OR = 2.30, 95% CI = 1.31–4.05). The results indicated that exposure to COFs from Chinese household cooking may be a risk factor for poor sleep quality among middle-aged Chinese population.

Foi realizada amostragem de fumos metálicos na zona respiratória de quatro grupos de soldadores e em um grupo de prensistas não expostos a fumos metálicos. As concentrações de metais obtidas foram comparadas com os limites de tolerância propostos pela American Conference of Governmental Industrial Hygienists - ACGIH - e adaptados à nossa jornada de trabalho. As concentrações encontradas estão próximas aos limites de tolerância e é enfatizada e discutida a dificuldade de decidir se estão acima ou abaixo do limite. O nível de exposição é comparado com os níveis de metais no sangue e urina encontrados abaixo dos limites de tolerância biológica. É evidenciada a necessidade de amostrar o ar dentro do elmo, próximo ao nariz do soldador e a impraticabilidade de um limite de tolerância gravimétrico, único, para a presente situação. / Metalic fumes was sampled from respiratory zone of four welders group and of one not exposed to welding fumes press operators group. The metal concentrations were compared with the threshold Limit Values proposed by the American Conference of Governmental Industrial Hygienists - ACGIH - and adapted to our working day shift. The concentrations are near the thresholds and the dificulty to decide that the values are above or below the standard is showed and discussed. The exposure levels are also compared with blood and urinary metal levels that were found below the biologic to lerance limits. The necessity of sampling the air from a position the nearest possible to the welder´s nose, and the impracticability of the use of a unic gravimetric standard for the present situation are showed.

Foi realizada amostragem de fumos metálicos na zona respiratória de quatro grupos de soldadores e em um grupo de prensistas não expostos a fumos metálicos. As concentrações de metais obtidas foram comparadas com os limites de tolerância propostos pela American Conference of Governmental Industrial Hygienists - ACGIH - e adaptados à nossa jornada de trabalho. As concentrações encontradas estão próximas aos limites de tolerância e é enfatizada e discutida a dificuldade de decidir se estão acima ou abaixo do limite. O nível de exposição é comparado com os níveis de metais no sangue e urina encontrados abaixo dos limites de tolerância biológica. É evidenciada a necessidade de amostrar o ar dentro do elmo, próximo ao nariz do soldador e a impraticabilidade de um limite de tolerância gravimétrico, único, para a presente situação. / Metalic fumes was sampled from respiratory zone of four welders group and of one not exposed to welding fumes press operators group. The metal concentrations were compared with the threshold Limit Values proposed by the American Conference of Governmental Industrial Hygienists - ACGIH - and adapted to our working day shift. The concentrations are near the thresholds and the dificulty to decide that the values are above or below the standard is showed and discussed. The exposure levels are also compared with blood and urinary metal levels that were found below the biologic to lerance limits. The necessity of sampling the air from a position the nearest possible to the welder´s nose, and the impracticability of the use of a unic gravimetric standard for the present situation are showed.

A new technique is developed for examining non-climatic variations in widths of annual tree rings. For each tree core, the technique involves making an adjustment for regional climate as inferred from a regional chronology based on surrounding sites. The technique is applied to two stands in Gila County, Arizona, where air pollution is potentially a limiting factor on tree-ring growth. For the stand closer to the pollution sources, a marked decrease in tree-ring widths minus climate is evident during the period 1908 to 1920. Although this decrease coincides with a period when two smelters were operating nearby, air pollution cannot be definitively identified as the cause of the decrease in ring widths.

The thesis deals with the implementation of a suction system for laser welding. The specific product is grate used for outdoor drainage. The original GMAW production technology is to be replaced by a laser. During the welding of S235JR steel, a significant development of exhaust gases was observed, which subsequently made the actual process impossible. Practical experiments were performed and evaluated using tensile testing and metallographic cut. Based on the results, the optimal position of the suction nozzle and welding parameters were recommended. The obtained values were re-verified by experiment. Furthermore, a suitable extraction device was proposed and an economic evaluation was performed.

The utilization of radial growth responses of trees to diagnose air pollution injury, and problems of growth defects interfering with the establishment of growth chronologies, is discussed. Cores from trees in an air pollution-stressed forest are examined for their potential to crossdate. Less than half, and usually less than a third of the trees on all plots can be crossdated, and number appears to be associated with changing conditions along a transect of elevational and pollution levels. Chronologies developed along this transect are presented.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 229-238).

A probabilistic spatial exposure simulation model (SESM) was designed to investigate the effect of time spent at work and commuting on estimates of chronic exposure to traffic-related air pollution in large populations. The model produces distributions of exposure estimates in six microenvironments (home indoor, work indoor, other indoor, outdoor, transit to work and transit other) for workers and non-workers, using randomly sampled time-activity patterns from the Canadian Human Activity Pattern Survey and work flow data from Statistics Canada. The SESM incorporates geographic detail through the use of property assessment data, shortest route analysis, and the use of a geographic information system (GIS) to develop pollution concentration distributions. The SESM was implemented and tested using data for 382 census tracts in the Greater Vancouver Regional District of British Columbia. Simulation results were found to be relatively insensitive to the choice of distance used to represent the typical range of non-work related trips; the use of a simple annual average pollution estimate versus a time-stratified annual average; and the use of different indoor/outdoor ratios representing the infiltration of ambient pollution into indoor locations. Substantial sensitivity was observed based on the use of different methods for producing spatial estimates of ambient air pollution. The SESM was used to explore variability in annual total exposure of workers to traffic-related nitrogen dioxide (NO2). Total exposure ranged from 8 μg/m3 to 35 μg/m3 of iv annual average hourly NO2 and was highest where ambient pollution levels are highest, reflecting the regional gradient of pollution in the study area and the relatively high percentage of time spent at home locations. Within census tract variation was observed in the partial exposure estimates associated with time spent at work locations, particularly in suburban areas where longer commuting distances are more prevalent. In these areas, some workers may have exposures 1.3 times higher than other workers residing in the same census tract. Exposures to NO2 associated with the activity of commuting to work were negligible. No statistically significant difference in total exposure estimates was found between female and male commuters, although there were small but observable differences at the upper end of the exposure distributions associated specifically with the work indoor microenvironment. These differences were highest in suburban areas (up to 3 μg/m3 of annual hourly average NO2 higher for female commuters, in relation to 99th percentile total exposures levels of approximately 37 μg/m3), illustrating the impact of systematically different work locations for female compared to male commuters in these same census tracts. Simulated exposures for workers, non-workers, and a base scenario where all time is spent at the residence only were compared. Statistically significant differences were found in the exposure distributions for workers versus non-workers, workers versus residence only, and non-workers versus residence only. Differences in exposure within census tracts were highest at the 10th and 90th percentiles, on the order of -5.4 to +6.5 μg/m3 of annual average hourly NO2 respectively for workers compared to non-workers, in relation to exposure estimates between 10 and 40 μg/m3 of annual average hourly NO2 on average.