This thesis describes a study undertaken between 1992 and 2001 to explore the possible health impacts of human exposure to pesticides. The study followed the health outcomes of approximately 4000 outdoor workers over a period of up to sixty-one years. These workers comprised two subcohorts of approximately even size, one composed of agricultural workers with high insecticide exposures, and the other made up of outdoor staff from local councils in the same area with little or no occupational exposure to insecticides. Mortality and morbidity were compared between the two groups, and with the general Australian community. The study identifies significantly increased mortality among both exposed and control subjects when compared to the Australian population. The major cause of this increase was mortality from smoking related diseases. The study also identifies significant increases in mortality among exposed subjects for a number of conditions that do not appear to be the result of smoking patterns, both when compared to the control group and the Australian population. These include pancreatic cancer in some DDT exposed subjects and asthma, diabetes, and leukaemia in subjects working with more modern chemicals. There was also an increase in self reported chronic illness and asthma, and lower neuropsychological functioning scores among surviving exposed subjects when compared to controls. Diabetes was also reported more commonly by subjects reporting occupational use of herbicides.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

<p>Sleep problems are one of the most common health complaints in the population. Furthermore, people often judge good sleep as crucial for everyday well-being and it has been shown that lack of sleep has negative health effects. However, sleep has not been a subject of much sociological study.</p><p>In this study sleep problems are analysed in different ways. First, a cross-sectional analysis is done in order to find out whether sleep problems in the population have increased from 1968 to 2000. Secondly, a longitudinal analysis is done to see how sleep problems pattern from middle-age to old-age. Last, it is analysed whether there are any differences in the sleep patterns from middle-age to old-age for manual workers and non-manuals.</p><p>This study shows that there has been an increase in sleep problems from 1968 to 2000 in the population. However the increase has only affected younger age groups (between the age 19-55), the elderly population is unaffected. The increase is found among both men and women. Longitudinal analyses of a cohort (born 1915-1925) followed from middle-age to old-age (for 34 years) showed that one out of four experienced an onset of sleep problems during the study. This is in line with earlier research stating that insomnia to a large part is age-related. Furthermore, it was found that manual workers had a larger increase of sleep problems across the 34 years than non-manuals, perhaps suggesting an accumulation effect.</p><p>All analyses were separated for gender and women constantly reported more sleep problems than men. This is not surprising since this relation have been found across almost all cultures and times. Nevertheless, in this study no increase of the gender gap was found with advancing age, a relation found in most other studies. However more research is needed to understand the reason behind the gendered nature of sleep problems.</p>

The purpose of this research was to explore non-persistence by vocational students in the College of Career and Vocational Education at the University of Alaska Anchorage. A cohort of 156 students were identified and tracked from fall 1989 through spring 1992. In the first part of the study, using the University of Alaska Anchorage Institutional Research data base, demographic characteristics of the cohort, their patterns of enrollment and performance were identified. In the second part of the study, a sample of 12 non-persisters within the cohort were interviewed to learn about their motives for enrolling in postsecondary vocational education, factors contributing to their withdrawal and their perceptions regarding the quality of their educational experiences. Traditional-age (19 and under) students were the dominant age group, representing 46 percent of the cohort. Eighty percent of the students within the cohort were full-time students taking 12 or more credits. Over half (55 percent) of the students were "early-leavers" who discontinued their education at some point within the first year of the study. The graduation rate for the cohort was 3.8 percent and, at the conclusion of the study, 7.1 percent of the original cohort had maintained continuous enrollment, however, if students attending in stop-and-go patterns were included, 14.7 percent were still persisting. Implications for further study revealed by the interviews of "early-leavers" (i.e., students who did not persist beyond the first or second semesters of the study) included the following questions: 1. What retention strategies, policies and procedures can be implemented to encourage persistence of vocational students beyond the first or second semester? 2. How can the University of Alaska Anchorage assist students with their career development and decision-making? 3. How can the University of Alaska Anchorage encourage the persistence of commuter students? / Graduation date: 1995

Thesis (Ph. D.)--University of Hong Kong, 2006. / Also available online.

This thesis examined associations between ecological indicators of residential radon and fine particulate matter air pollution (PM2.5) and lung cancer mortality using data from the American Cancer Society Cancer Prevention Study-II (CPS-II) prospective cohort. Nearly 1.2 million CPS-II participants were recruited in 1982. Mean county-level residential radon concentrations were linked to study participants according to ZIP code information at enrollment (mean (SD) = 53.5 (38.0) Bq/m3). Cox proportional hazards regression models were used to obtain adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for lung cancer mortality associated with radon. After necessary exclusions, a total of 811,961 participants in 2,754 counties were retained for analysis. A significant positive linear trend was observed between categories of radon concentrations and lung cancer mortality (p = 0.02). A 15% (95% CI 1 - 31%) increase in the risk of lung cancer mortality was observed per each 100 Bq/m3 radon. Radon was also positively associated with chronic obstructive pulmonary disease mortality (HR per each 100 Bq/m3 = 1.13, 95% CI 1.05 - 1.21). No clear associations were observed between radon and non-respiratory mortality. In lifelong never smokers (n = 188,699), each 10 µg/m3 increase in mean metropolitan statistical area PM2.5 concentrations was associated with a 15-27% increase in the risk of lung cancer death which strengthened among individuals with a history of asthma or any prevalent chronic lung disease at enrollment (p for interaction < 0.05). There was no association between PM2.5 and mortality from non-malignant respiratory disease. In conclusion, this thesis observed significant positive associations between ecological indicators of residential radon and PM2.5 concentrations and lung cancer mortality. These findings further support efforts to reduce radon concentrations in homes to the lowest possible level and strengthens the evidence that ambient concentrations of PM2.5 measured in recent decades are associated with small but measurable increases in lung cancer mortality. Further research is needed to better understand possible complex inter-relationships between environmental risk factors, chronic lung disease, and lung cancer.

No description available.

This thesis examined associations between ecological indicators of residential radon and fine particulate matter air pollution (PM2.5) and lung cancer mortality using data from the American Cancer Society Cancer Prevention Study-II (CPS-II) prospective cohort. Nearly 1.2 million CPS-II participants were recruited in 1982. Mean county-level residential radon concentrations were linked to study participants according to ZIP code information at enrollment (mean (SD) = 53.5 (38.0) Bq/m3). Cox proportional hazards regression models were used to obtain adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for lung cancer mortality associated with radon. After necessary exclusions, a total of 811,961 participants in 2,754 counties were retained for analysis. A significant positive linear trend was observed between categories of radon concentrations and lung cancer mortality (p = 0.02). A 15% (95% CI 1 - 31%) increase in the risk of lung cancer mortality was observed per each 100 Bq/m3 radon. Radon was also positively associated with chronic obstructive pulmonary disease mortality (HR per each 100 Bq/m3 = 1.13, 95% CI 1.05 - 1.21). No clear associations were observed between radon and non-respiratory mortality. In lifelong never smokers (n = 188,699), each 10 µg/m3 increase in mean metropolitan statistical area PM2.5 concentrations was associated with a 15-27% increase in the risk of lung cancer death which strengthened among individuals with a history of asthma or any prevalent chronic lung disease at enrollment (p for interaction < 0.05). There was no association between PM2.5 and mortality from non-malignant respiratory disease. In conclusion, this thesis observed significant positive associations between ecological indicators of residential radon and PM2.5 concentrations and lung cancer mortality. These findings further support efforts to reduce radon concentrations in homes to the lowest possible level and strengthens the evidence that ambient concentrations of PM2.5 measured in recent decades are associated with small but measurable increases in lung cancer mortality. Further research is needed to better understand possible complex inter-relationships between environmental risk factors, chronic lung disease, and lung cancer.

During the past decades, the incidence of osteoporotic fractures has increased dramatically in the Western world. Consumption of coffee and intake of caffeine have in some studies been found to be associated with increased risk of osteoporotic fractures, but overall results from previous research are inconsistent. Despite weak evidence, some osteoporosis organisations recommend limiting daily coffee or caffeine intake. The primary aim of this thesis was to study the association between long-term consumption of coffee and bone mineral density (BMD), incidence of osteoporosis and fractures. A secondary aim was to study the relation between tea consumption and fracture risk. An increased risk of osteoporotic fractures in individuals who consumed ≥ 4 cups of coffee vs &lt; 1 cup coffee per day was demonstrated in a study of 31,257 Swedish middle-aged and elderly women (a part of the Swedish Mammography Cohort - SMC) when calcium intake was low (&lt; 700 mg/day). However, no higher risks of osteoporosis or fractures were observed in the full SMC with increasing coffee consumption. In the full SMC (n = 61,433) the follow-up was longer and the number of fractures was higher. Similarly, no statistically significant associations between consumption of coffee (≥ 4 cups of coffee vs &lt; 1 cup) and incidence of osteoporotic fractures were observed in the Cohort of Swedish Men (COSM), including 45,339 men. Calcium intake did not modify the results from the investigations performed in the full SMC or COSM. Nonetheless, a 2 - 4% lower BMD at measured sites was observed in men participating in the PIVUS cohort and in women from a sub-cohort of the SMC who consumed ≥ 4 cups of coffee vs &lt; 1 cup daily. Individuals with high coffee intake and rapid metabolism of caffeine had lower BMD at the femoral neck. No association between tea consumption and risk of fractures was found in the studies. In conclusion, the findings presented in this thesis demonstrate that high consumption of coffee may be associated with a modest decrease in BMD. However, there was no evidence of a substantially increased incidence of osteoporosis or fractures typically associated with osteoporosis.

Sleep problems are one of the most common health complaints in the population. Furthermore, people often judge good sleep as crucial for everyday well-being and it has been shown that lack of sleep has negative health effects. However, sleep has not been a subject of much sociological study. In this study sleep problems are analysed in different ways. First, a cross-sectional analysis is done in order to find out whether sleep problems in the population have increased from 1968 to 2000. Secondly, a longitudinal analysis is done to see how sleep problems pattern from middle-age to old-age. Last, it is analysed whether there are any differences in the sleep patterns from middle-age to old-age for manual workers and non-manuals. This study shows that there has been an increase in sleep problems from 1968 to 2000 in the population. However the increase has only affected younger age groups (between the age 19-55), the elderly population is unaffected. The increase is found among both men and women. Longitudinal analyses of a cohort (born 1915-1925) followed from middle-age to old-age (for 34 years) showed that one out of four experienced an onset of sleep problems during the study. This is in line with earlier research stating that insomnia to a large part is age-related. Furthermore, it was found that manual workers had a larger increase of sleep problems across the 34 years than non-manuals, perhaps suggesting an accumulation effect. All analyses were separated for gender and women constantly reported more sleep problems than men. This is not surprising since this relation have been found across almost all cultures and times. Nevertheless, in this study no increase of the gender gap was found with advancing age, a relation found in most other studies. However more research is needed to understand the reason behind the gendered nature of sleep problems.