In recent decades, rates of type 2 diabetes mellitus (T2DM) and diabetic complications have reached epidemic proportions among Canadian Aboriginal people. Evidence in several populations suggests that abnormal birth weight, particularly low birth weight (LBW) and possibly high birth weight (HBW) may be linked to the development of T2DM. LBW often reflects poor maternal health/ nutritional status which may interfere with normal pancreatic development. HBW is a frequent complication of diabetic pregnancies which are associated with obesity and carbohydrate intolerance in adulthood. Since Saskatchewan Aboriginal newborns historically had higher rates of LBW, and more recently have experienced higher HBW rates, it follows that sub-optimal maternal/ fetal health may be important in the epidemic of T2DM in this population.<p> This thesis describes a case-control study that used Saskatchewan Health databases to determine the relationship between birth weight and T2DM. A sample of 846 adult diabetic Registered Indians (RI) were age and sex matched to three control groups: 1) non-diabetic RI, 2) diabetic general population (GP) subjects, and 3) non-diabetic GP subjects. RI subjects were identified as such by the provincial Health Insurance Registration File.<p> The results of this study show a significant association between HBW (> 4000 grams) and T2DM for RI people [odds ratio (OR) 1.63; 95% confidence interval (CI) 1.20, 2.24]. This association increased in strength from the middle to the latter part of this century and was found to be stronger for RI females than RI males. The comparison of birth weights within the four study groups revealed that diabetic RI (16.2%) were significantly more likely (p<0.05) than controls (10.7%,10.0%, 7.5% respectively) to have HBW. An association between LBW and T2DM (< 2500 grams) was not evident within either RI or GP sample populations.<p> The findings of this study support the hypothesis that HBW and its causes may be risk factors for T2DM among RI people. Programs to prevent gestational diabetes, and to diagnose and optimally manage diabetes during pregnancy could help to reduce rates of diabetes in future generations of Aboriginal peoples.

This study is to probe into the quantitative aspects of in vocabulary in the first volumes of the major three senior high (SH) school English textbooks and the major three vocational high (VH) school English textbooks. Not only the vocabulary lists, but also the unlisted new words in the related sections which are categorized into 22 corpora are explored and compared in terms of the size of new words, the consistency between junior high school (JH) vocabulary lists and SH/VH textbooks, the new-word density, and the frequency of word exposures. In addition to the six commercial SH/VH English textbooks from three major publishers (Far East, Lungteng, and Sanmin), four JH word lists are included: two word lists of the old centralized Junior High School Required (Word-JHA) and Elective (Word-JHB) English Course by the National Institute for Compilation and Translation and two new word lists of 1,000 productive vocabulary (Word-JH1000) and 1,000 receptive vocabulary (Word-JH2000) by the MOE. The major findings of this study are as follows: 1. The word size, particularly the unlisted new words, is big. For those SH students who learn both Word-JH1000 and Word-JH2000, they face 9.05%~13.36% of unlisted new words in reading sections and encounter 17.92%~22.55% of unlisted new words in the whole textbooks. For those VH students who learn both Word-JH1000 and Word-JH2000, they face 5.77%~12.62% of unlisted new words in reading sections and encounter 16.05%~21.90% of unlisted new words in the whole textbooks. 2. Even though the new JH vocabulary lists (Word-JH1000 & Word-JH2000) provides a larger proportion of overlapping with the 22 SH/VH corpora than the old JH vocabulary (Word-JHA & Word-JHB), the consistency of vocabulary between JH and SH/VH is not adequate enough to reach the ¡§all-or-nothing threshold¡¨ (80% known words in a certain text). 3. Both SH and VH textbooks are too dense with new words to reach the ¡§probabilistic threshold¡¨ (95% known words in a certain text), the density index of an efficient textbook for the first year. 4. The frequency of word exposures is too low to be well-learned (more than 80% beneath the six-time threshold; more than 40% are one-timers). The findings have some pedagogical implications regarding the suggestions for the policy-makers, publisher, JH/SH/VH teachers and students.

No description available.

The objective of this thesis was to investigate firefighters’ exposures to carcinogens and mutagens. This thesis aimed to (1) characterize firefighters’ exposures during emergency fire suppression, (2) examine the use of silicone wristbands as passive samplers to assess firefighters’ exposures, and (3) assess the ability of post-fire decontamination protocols to reduce firefighters’ exposures. Chapter 1 provides a general introduction and background information on the concepts covered in this thesis. In Chapter 2, I examined air and surface contamination with polycyclic aromatic hydrocarbons (PAHs) and metals, both at fire stations and following emergency fire suppression activities. I also investigated the ability of current laundering methods to remove surficial PAHs and metals from firefighters’ personal protective equipment. In Chapter 3, I assessed the ability of silicone wristband passive samplers to measure firefighters’ exposures to PAHs during live fire training. In Chapter 4, I assessed the ability of three post-fire dermal decontamination methods to remove surface contamination and reduce internal dose. In Chapter 5, conclusions and implications for each chapter are summarized. Future directions for the field are described. The overall conclusions for this thesis were: i. firefighters experience significant occupational exposures to carcinogens during emergency fire suppression and live fire training; ii. the ability of silicone wristbands to properly sample PAHs is altered in a fire environment and correction factors must be determined to improve their utility for exposure assessment; iii. current post-fire dermal decontamination methods, which are intended to reduce firefighters’ exposures, do not reduce their internal dose of PAHs.

O atual modelo de desenvolvimento econômico, que tem como uma de suas bases a acentuada produção de bens de consumo, é responsável pelo aumento crescente de riscos ambientais que incidem nas questões de saúde das populações. Esse modelo é também responsável por um aumento na geração de resíduos sólidos, considerado um dos problemas ambientais emergentes com significativos impactos para a saúde humana. O crescimento na geração de resíduos vem sendo acompanhado por um aumento considerável no número de catadores de material reciclável, que encontram nessa atividade uma estratégia de sobrevivência. Esse grupo de trabalhadores encontra-se potencialmente exposto a maiores riscos no campo da saúde em função de sua ocupação. Na presente investigação, avaliaram-se os níveis de exposição aos metais cádmio (Cd), chumbo (Pb), mercúrio (Hg) e níquel (Ni) em catadores de material reciclável de quatro cooperativas na Região Metropolitana de São Paulo (RMSP) e os resultados foram comparados com estudos de biomonitoramento também realizados na RMSP .Foram coletadas amostras de sangue de 226 indivíduos (IC:95%, precisão 6%) e aplicados questionários para o levantamento de características associadas às concentrações de metais e à presença de valores acima dos Valores de Referência (VR) definidos por estudos de biomonitoramento. As concentrações médias de Cd (MA: 0,47 ug/L; MG: 0,34 ug/L) foram quase quatro vezes superiores às apontadas no estudo de referência e 24,3% dos indivíduos apresentaram concentrações de Cd acima dos VR. As concentrações médias de Pb (MA: 39,13 ug/L; MG: 34,11 ug/L) foram 1,4 vezes superiores às da população de referência e 10,6% dos indivíduos apresentaram concentrações de Pb acima do VR. As concentrações médias de Hg (MA: 1,46 ug/L; MG: 0,94 ug/L) não foram significativamente diferentes da população de referência, porém 4,9% dos indivíduos apresentaram concentrações de Hg acima do VR. As concentrações médias de níquel (Ni) (MA:3,3 ug/L; MG:1,89 ug/L) apresentaram grande variabilidade, não sendo possível realizar inferências sobre os níveis de exposição. Os resultados encontrados apontam para uma maior exposição ao Cd entre os catadores, possivelmente relacionada ao trabalho com a reciclagem, porém as fontes específicas não puderam ser determinadas por este estudo. Os resultados apontam também uma maior exposição ao Pb, porém de menor magnitude, o que pode estar relacionado com a condição socioeconômica e maior percentual de tabagistas na população do estudo e não necessariamente com a ocupação que exercem / The current model of economic development, which has as one of its bases a constant increase in production and consumption, is responsible for the intensification of environmental risks that can compromise a population\'s health. This model is also responsible for the continued growth in waste generation which is accompanied by a considerable increase in the number of recyclable materials collectors, who find in this activity a survival strategy. This population group that has for decades played an important role in solid waste management, now has greater exposures to health risks due to their daily activity. In the present study, the levels of exposure to the metals cadmium (Cd), lead (Pb), mercury (Hg) and nickel (Ni) were evaluated in recyclable materials collectors from four cooperatives in the Metropolitan Region of São Paulo (MRSP). Blood samples were collected from 226 individuals (CI: 95%, accuracy 6%) and the results were compared with other biomonitoring studies from MRSP. Questionnaires were applied to obtain information regarding variables that could influence the blood levels of the metals under study. The mean concentrations of Cd found (AM: 0.47 ug/L; GM: 0.34 ug/L) were almost four times that the ones found in the reference study and 24,3% of the individuals presented Cd concentrations above the Reference Values (RV). The mean concentrations of Pb in the collectors (AM: 39.13 ug/L; GM: 34.11 ug/L) were also significantly higher than the mean concentration in the reference study population (about 1.4 times) and 10,6% of the collectors presented Pb concentrations above the RV. The mean concentrations of mercury (AM: 1.46 ug/L; GM: 0.94 ug/L) were not significantly higher than the mean concentration found in the reference study. The concentration of Ni presented a large variability, so it was not possible to make inferences about the exposure to this metal. This study indicates that recyclable materials collectors have a greater exposure to Cd when compared with the general population, and this is possibly related to the work developed by these individuals, even though the sources could not be determined by this study. It also indicated that the collectors have a greater exposure to Pb, but the magnitude of the results might be explained by the socioeconomic characteristics and the larger amount of smokers among the sampled population

O atual modelo de desenvolvimento econômico, que tem como uma de suas bases a acentuada produção de bens de consumo, é responsável pelo aumento crescente de riscos ambientais que incidem nas questões de saúde das populações. Esse modelo é também responsável por um aumento na geração de resíduos sólidos, considerado um dos problemas ambientais emergentes com significativos impactos para a saúde humana. O crescimento na geração de resíduos vem sendo acompanhado por um aumento considerável no número de catadores de material reciclável, que encontram nessa atividade uma estratégia de sobrevivência. Esse grupo de trabalhadores encontra-se potencialmente exposto a maiores riscos no campo da saúde em função de sua ocupação. Na presente investigação, avaliaram-se os níveis de exposição aos metais cádmio (Cd), chumbo (Pb), mercúrio (Hg) e níquel (Ni) em catadores de material reciclável de quatro cooperativas na Região Metropolitana de São Paulo (RMSP) e os resultados foram comparados com estudos de biomonitoramento também realizados na RMSP .Foram coletadas amostras de sangue de 226 indivíduos (IC:95%, precisão 6%) e aplicados questionários para o levantamento de características associadas às concentrações de metais e à presença de valores acima dos Valores de Referência (VR) definidos por estudos de biomonitoramento. As concentrações médias de Cd (MA: 0,47 ug/L; MG: 0,34 ug/L) foram quase quatro vezes superiores às apontadas no estudo de referência e 24,3% dos indivíduos apresentaram concentrações de Cd acima dos VR. As concentrações médias de Pb (MA: 39,13 ug/L; MG: 34,11 ug/L) foram 1,4 vezes superiores às da população de referência e 10,6% dos indivíduos apresentaram concentrações de Pb acima do VR. As concentrações médias de Hg (MA: 1,46 ug/L; MG: 0,94 ug/L) não foram significativamente diferentes da população de referência, porém 4,9% dos indivíduos apresentaram concentrações de Hg acima do VR. As concentrações médias de níquel (Ni) (MA:3,3 ug/L; MG:1,89 ug/L) apresentaram grande variabilidade, não sendo possível realizar inferências sobre os níveis de exposição. Os resultados encontrados apontam para uma maior exposição ao Cd entre os catadores, possivelmente relacionada ao trabalho com a reciclagem, porém as fontes específicas não puderam ser determinadas por este estudo. Os resultados apontam também uma maior exposição ao Pb, porém de menor magnitude, o que pode estar relacionado com a condição socioeconômica e maior percentual de tabagistas na população do estudo e não necessariamente com a ocupação que exercem / The current model of economic development, which has as one of its bases a constant increase in production and consumption, is responsible for the intensification of environmental risks that can compromise a population\'s health. This model is also responsible for the continued growth in waste generation which is accompanied by a considerable increase in the number of recyclable materials collectors, who find in this activity a survival strategy. This population group that has for decades played an important role in solid waste management, now has greater exposures to health risks due to their daily activity. In the present study, the levels of exposure to the metals cadmium (Cd), lead (Pb), mercury (Hg) and nickel (Ni) were evaluated in recyclable materials collectors from four cooperatives in the Metropolitan Region of São Paulo (MRSP). Blood samples were collected from 226 individuals (CI: 95%, accuracy 6%) and the results were compared with other biomonitoring studies from MRSP. Questionnaires were applied to obtain information regarding variables that could influence the blood levels of the metals under study. The mean concentrations of Cd found (AM: 0.47 ug/L; GM: 0.34 ug/L) were almost four times that the ones found in the reference study and 24,3% of the individuals presented Cd concentrations above the Reference Values (RV). The mean concentrations of Pb in the collectors (AM: 39.13 ug/L; GM: 34.11 ug/L) were also significantly higher than the mean concentration in the reference study population (about 1.4 times) and 10,6% of the collectors presented Pb concentrations above the RV. The mean concentrations of mercury (AM: 1.46 ug/L; GM: 0.94 ug/L) were not significantly higher than the mean concentration found in the reference study. The concentration of Ni presented a large variability, so it was not possible to make inferences about the exposure to this metal. This study indicates that recyclable materials collectors have a greater exposure to Cd when compared with the general population, and this is possibly related to the work developed by these individuals, even though the sources could not be determined by this study. It also indicated that the collectors have a greater exposure to Pb, but the magnitude of the results might be explained by the socioeconomic characteristics and the larger amount of smokers among the sampled population

Occupational skin and respiratory symptoms, and disease, are common problems. Workers can develop new disease or aggravate existing disease as a result of exposures at work. Many workers are exposed to chemicals that can cause both respiratory and skin responses and there is evidence that some workers experience symptoms in both systems. There is also evidence that skin exposure may lead to sensitization and the development of respiratory disease. There is very little research that has examined both airborne and skin exposures together with lung and skin outcomes. The purpose of this thesis was to further investigate the relationships between occupational exposures, skin symptoms and disease, and respiratory symptoms and disease. Four studies were undertaken to improve our understanding of these complex relationships. Results from a study of clinical patch test data determined that seven of the ten most common occupational contact allergens are also capable of causing occupational asthma and that these common occupational exposures may not be recognized as sensitizers in common reference materials. Exposure-response relationships for skin symptoms were modeled in bakery workers and auto body shop workers using historical data; significant exposure-response relationships were found for auto body workers. In two separate studies of concurrent skin and respiratory symptoms, workers did report concurrent skin and respiratory symptoms. In predictive models, subjects reporting a history of eczema were more likely to report concurrent skin and respiratory symptoms. Overall, the results from this thesis provide more evidence that the skin and respiratory systems are associated. This body of work suggests that: (1) several common occupational exposures can cause disease in both the skin and respiratory system; (2) a portion of workers report both skin and respiratory symptoms; and (3) exposure-response relationships do exist for skin symptoms, both work-related and non-work-related. Future studies need to gather detailed information about exposure and response in both systems in order to better determine the role of exposure(s) in the development of skin and respiratory symptoms. Improved understanding of these relationships will allow for more targeted and effective exposure prevention strategies and will ultimately reduce the burden of occupational disease.

Introduction The main objectives of this study were: 1) to examine the prevalence and characteristics of opioid exposures, 2) to estimate the economic costs associated with opioid poisonings, and 3) to examine the characteristics associated with opioid poisoning-related health care resource use (HCRU) and costs in children. Methods Data from the National Poison Data System from January 1, 2010 to December 31, 2014 were utilized to examine the prevalence and characteristics of opioid exposures and poisonings in children <18 years. Economic costs were estimated using the 2012 Nationwide Emergency Department Sample, Kids’ Inpatient Database, Multiple Cause-of-Death file and other published sources, applying a societal perspective. Direct costs included costs associated with ED visits, hospitalizations and ambulance transports. Indirect cost included productivity costs due to caregivers’ absenteeism and premature mortality among children. Results There were a total of 83,418 pediatric opioid exposures and nearly half of them resulted in poisoning. The epidemiology of opioid exposures differed considerably by age. Opioid exposures were more prevalent and mainly accidental in young children. Exposures in adolescents were more likely to be intentional and severe. The total economic costs of pediatric opioid poisonings in the United States were calculated at $230.8 million in 2012. Total direct costs were estimated to be over $21.1 million. Total productivity costs were calculated at $209.7 million, and 98.6% of these costs were attributed to opioid poisoning-related mortality. Conclusions Opioid exposures and poisonings in children continue to occur and impose an economic burden on the society.

Master of Science / Department of Statistics / Wei-Wen Hsu / Polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) are endocrine disrupting chemicals which can imbalance the hormonal system in the human body and lead to deleterious diseases such as diabetes, irregular menstrual cycles, endometriosis, and breast cancer. These chemicals as environmental exposures still exist in the environment and food chains and can be accumulated in human fatty tissues for many years. These chemicals can also be passed from mothers to their children through placental transfer or breastfeeding; therefore, their offspring may be at increased risk of adverse health outcomes from these inherited chemicals. However, it is still unclear how the parental association with offspring health outcomes and the inter-generational phenotypic inheritance could be affected by these chemical compounds. In this study, we mainly focus on how PCBs and DDE can affect the inheritance of Body Mass Index (BMI) across generations, as BMI is the primary health outcome (or phenotype) linked to diabetes. We propose a biometrical inheritance model to investigate the effects of PCBs and DDE on the heritability of BMI over two generations. Technically, a linear mixed effects model is developed based on the decomposition of phenotypic variance and assuming the variance of the environmental effect depends on parental exposures. The proposed model is evaluated extensively by simulations and then is applied to Michigan Fisheater Cohort data for answering the research question of interest.

Hazardous noise exposures and hearing loss have been documented among farmers and farm workers for many years. However, little is known about the noise exposures during specific agricultural work tasks and their effect on hearing loss. The objective of this dissertation was to assess the effects of specific agricultural tasks on hearing loss and their contribution to total noise exposures. Three studies were conducted to accomplish this objective. The first study examined associations between hearing sensitivity among rural residents (nfarmer = 960, nnon-farmers = 608) and self-reported years of participation in 12 agricultural tasks. Logistic regression analysis was used to examine associations between agricultural activities and hearing loss >25dB. Linear regression analysis was used to examine associations between agricultural tasks and mean decibels of hearing loss. The results indicated farmers have greater hearing loss than non-farmers. However years of participation in specific agricultural tasks was poorly associated with hearing loss. This result suggests that self-reported years engaging in specific agricultural activities may be a poor surrogate for true noise exposure In the second study noise exposures (personal dosimetry) and corresponding task data (direct observation) were collected on 18 grain farms, and mean noise exposures (dBA) were calculated for specific agricultural tasks. Noise exposures ranged from 78.6 dBA to 99.0 dBA across all tasks. The noise exposures for each task varied greatly (large standard deviation and maximum exposure) with most of the variability within the farms. Although specific tasks with intense noise exposures were identified, most comparisons of mean noise exposures from one task to another were not statistically different and intense exposures were present for nearly all tasks. Therefore, controlling noise only for those tasks with the greatest mean noise exposures may not completely eliminate hazardous exposures or the hearing loss risk. For the third study, estimates of 8-hr time-weighted-average (TWA) noise exposures were calculated using time-at-task observations from one population of farmers and prior dosimeter measured mean task-based noise exposures from an independent population of farmers. Additionally, dosimeter measured daily noise exposures from the independent population of farmers were also analyzed to identify significant determinants of noise exposure. Simple linear regression analysis was used to compare estimated and actual dosimeter-measured 8-hr TWA noise exposures. The noise exposure determinants were identified by conducting multivariable linear mixed-effects regression analysis on the one-minute noise measurements from the dosimeter measured daily noise exposures. The results indicated the estimated and measured 8-hr TWA noise exposures varied considerably. Therefore, the estimates were not considered reliable. Furthermore, task, number of noise sources and work area were found to have a statistically significant association with noise exposure. In summary, hearing loss and noise exposures among agricultural populations are complex and cannot be completely explained by examining agricultural tasks only. More detailed evaluations of tasks are needed to increase the understanding of hearing loss and noise exposure in this dynamic work environment.