Clear evidence shows a relationship between working in swine facilities and developing respiratory illnesses. Health effects have been associated with exposures to the combination of dust, ammonia, and carbon dioxide (CO2). This study examined whether room concentrations of combustion gases could be improved by changing the in-room vented heaters common to animal production operations to heaters that vent combustion gases outside. Concentrations of CO2 and carbon monoxide (CO) were monitored during two winter seasons, with the 2013-14 season using the traditional gas-fired heater (Guardian 60, L.B.White Co.) and the 2014-15 winter using new vented heaters (Effinity93, Modine Manufacturing Co.) Direct-reading CO (VRAE, Rae Systems) and CO2 (ToxieRAE Pro, Rae Systems) monitors were deployed at fixed stations throughout the farrowing barn to measure gas concentrations. Differences in mean gas concentrations between heater types, as well as the relationship between CO2 and temperature, sow, and piglet count, were evaluated using linear regression. Carbon dioxide concentrations exceeded industry recommended limits (1540 ppm) on all sample days (N=18) with the standard in-room vented heaters in operation: concentrations averaged half of the TLV (2500 ppm). With the new vented heaters, 24-hour averaged CO2 concentrations exceeded industry recommended limits on only three out of 20 sample days: concentrations averaged 1400 ppm. The new heater significantly reduced CO2 by 44% and CO by 60% from 2.0 to 0.8 ppm (p2=0.75) between CO2 and production factors (temperature, sow and piglet count) for the new heater: CO2 (ppm) = 482 - 22.4(Temp °C) + 43(# sow) + 5.6(# piglet). Similar analysis for the old heater identified similar trends but substantially different intercept (1700 ppm) and temperature factor (-36.9). While CO2 is still generated from swine respiration, we found significant reductions in room concentrations with the simple replacement of commonly used equipment. Future work will include an assessment of the longevity of these heaters in the swine barn environment

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

<p> Asthma is a multifactorial chronic disease that has shown a marked increase in prevalence over the past few decades, both in Canada and worldwide. Basic knowledge gaps remain about the pathways through which risk factors influence adult asthma. More adult women than men have asthma, and a growing body of research suggests that associations between certain risk factors and asthma may differ by sex. The aim of this thesis was to investigate the socioeconomic, environmental and personal correlates of asthma in men and women.</p> <p> Data for this thesis were obtained from a cross-sectional study conducted in 2003 in the rural Canadian town of Humboldt, Saskatchewan. The survey response rate was 71% of the resident target population, with 1177 females and 913 males aged 18 to 79 participating in the study. Researchers collected objective data on atopy (skin prick test), and body mass index. Exposures and history of physician-diagnosed asthma in the past year (current asthma) and during the participants lifetime (ever asthma) were self-reported. Multivariable logistic regression models adjusted for age, atopy, and parental asthma history were used to evaluate associations of correlates with asthma. The model building process was based on a conceptual framework of three categories: socioeconomic variables, home and work environment, and personal factors. </p> <p> The prevalence of asthma was higher in women than men (ever asthma: 10.2% of women versus 5.8% of men; current asthma: 6.2% of women versus 2.8% of men). The logistic regression models for ever asthma and current asthma showed several sex differences. The sequential addition of each category of socioeconomic, environmental, and personal variables contributed significantly to model fit in women, but not in men. Living in a mobile, attached or multiple-family home, household dampness, and overweight/obesity were strong risk factors for female asthma, while farm living, occupational grain dust exposure, and regular alcohol use emerged as protective factors. Male models revealed a strong significant association between household dampness and current asthma. A significant interaction between home type and age was found only in females. Women living in homes other than single-family detached dwellings were more likely to have asthma, an association that decreased in strength with increasing age. </p> <p> These results suggest that several risk factors for adult asthma may be sex-specific, therefore emphasizing the importance of considering sex as a potential effect modifier in future adult asthma epidemiology studies.</p>

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

<p> Asthma is a multifactorial chronic disease that has shown a marked increase in prevalence over the past few decades, both in Canada and worldwide. Basic knowledge gaps remain about the pathways through which risk factors influence adult asthma. More adult women than men have asthma, and a growing body of research suggests that associations between certain risk factors and asthma may differ by sex. The aim of this thesis was to investigate the socioeconomic, environmental and personal correlates of asthma in men and women.</p> <p> Data for this thesis were obtained from a cross-sectional study conducted in 2003 in the rural Canadian town of Humboldt, Saskatchewan. The survey response rate was 71% of the resident target population, with 1177 females and 913 males aged 18 to 79 participating in the study. Researchers collected objective data on atopy (skin prick test), and body mass index. Exposures and history of physician-diagnosed asthma in the past year (current asthma) and during the participants lifetime (ever asthma) were self-reported. Multivariable logistic regression models adjusted for age, atopy, and parental asthma history were used to evaluate associations of correlates with asthma. The model building process was based on a conceptual framework of three categories: socioeconomic variables, home and work environment, and personal factors. </p> <p> The prevalence of asthma was higher in women than men (ever asthma: 10.2% of women versus 5.8% of men; current asthma: 6.2% of women versus 2.8% of men). The logistic regression models for ever asthma and current asthma showed several sex differences. The sequential addition of each category of socioeconomic, environmental, and personal variables contributed significantly to model fit in women, but not in men. Living in a mobile, attached or multiple-family home, household dampness, and overweight/obesity were strong risk factors for female asthma, while farm living, occupational grain dust exposure, and regular alcohol use emerged as protective factors. Male models revealed a strong significant association between household dampness and current asthma. A significant interaction between home type and age was found only in females. Women living in homes other than single-family detached dwellings were more likely to have asthma, an association that decreased in strength with increasing age. </p> <p> These results suggest that several risk factors for adult asthma may be sex-specific, therefore emphasizing the importance of considering sex as a potential effect modifier in future adult asthma epidemiology studies.</p>

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

Two billion people world-wide use kerosene-burning lamps for household lighting. These lamps produce large quantities of soot. In Chapter 2, I describe our field study examining 230 people in rural Uganda. I show that kerosene lamps are a major source of smoke exposure in the developing world, and that replacing such lamps with solar-powered lights reduces indoor soot levels 17-fold, leading to significant improvements in health within months. This finding is particularly notable because respiratory disease is the #1 cause of death in children under 5 worldwide. Because solar cells are a challenge to manufacture in the developing world, I next examined the potential of harvesting electrons from soil-based microbes as a source of clean energy. Such devices are known as microbial fuel cells (MFCs); because soil is available everywhere, MFCs can, in principle, be locally constructed all over the world. In Chapter 3, I describe our exploration of the biology of MFCs, using high-throughput DNA sequencing to demonstrate a role for genus Pseudomonas in energy production. I also examine numerous agricultural products available throughout the developing world to determine whether any could serve as a suitable ‘feed’ for MFC soil. I find that dried animal blood increases MFC energy production 10-fold. In Chapter 4, I describe our design of a modular, stackable MFC, demonstrate that it can be easily constructed in rural Africa, and use it to power lights and to charge a cell phone battery.

The role of the spatial representation in the relation between chronic exposure to NO2 and respiratory health outcomes is studied through a spatial approach encompassing three conceptual components: the geography of susceptibility, the geography of exposure and the geography of risk. A spatially explicit methodology that defined natural neighbourhoods for the city of Ottawa is presented; it became the geography of analysis in this research. A LUR model for Ottawa is developed to study the geography of exposure. Model sensitivity to the spatial representation of population showed that dasymetric population mapping did not provide significant improvements to the LUR model over population at the dissemination block level. However, both the former were significantly better than population represented at the dissemination area. Spatial representation in the geography of exposure was also evaluated by comparing four kriging and cokriging interpolation models to the LUR. Geostatistically derived NO2 concentration maps were weakly correlated with LUR model results. The relationship between mean NO2 concentrations and respiratory health outcomes was assessed within the natural neighbourhoods. We find a statistically significant association between NO2 concentrations and respiratory health outcomes as measured by global bivariate Moran’s I. However, for regression model building, NO2 had to be forced into the model, demonstrating that NO2 is not one of the main contributing variables to respiratory health outcomes in Ottawa. The results point toward the importance of the socioeconomic status on the health condition of individuals. Finally, the role of spatial representation was assessed using three different spatial structures, which also permitted to better understand the role of the modifiable areal unit problem (MAUP) in the study of the relationship between exposure to NO2 and health. The results confirm that NO2 concentration is not a major contributing factor to the respiratory health in Ottawa but clearly demonstrate the implications that the use of opportunistic administrative boundaries can have on results of exposure studies. The effects of the MAUP, the scale effect and the zoning effect, were observed indicating that a spatial structure that embodies the scale of major social processes behind the health condition of individuals should be used when possible.

Household air pollution (HAP) has been recognized as one of the lethal causes of millions of premature deaths every year, victimizing mainly children and women. Literature suggests that transition to modern cooking fuels such as electricity, biogas from the conventional ones, for instance, fuelwood, coal, can reduce HAP, thus minimize the likelihood of respiratory health problems among household members. This study explores whether cooking fuels has an impact on children's respiratory health in the context of Nigeria, and in particular, whether modern cooking fuels can be a solution to this problem. By using the children recode of the survey data collected by the Demographic and Health Survey (DHS) for the year 2018, this study finds support to the claim that modern cooking fuels can reduce the probability of Acute Respiratory Infections (ARI) symptoms among children aged below 5 years in Nigeria. This probability is also found contingent on the age, gender, and education of the household heads. However, with regards to individual fuel types, the result seems inconclusive in some instances, mostly due to a lack of observations. The policy implication is that to reduce ARI among children, households should be encouraged to adopt modern cooking fuels, and this should follow with increasing education and empowerment opportunities for women in the household.

No description available.