Browsing by Subject "air pollution"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Air-quality related health impacts of food in the United States
    (2021-05) Domingo, Nina Gabrielle
    The challenge of feeding a growing and increasingly affluent population has spurred interest in identifying diets and food production practices that improve human health and protect the environment. The environmental impacts of our food system on climate change, on land, energy, and water use, and on water quality are well established. Less is known about the role of food in influencing human health via reduced air quality. This is despite the food sector being a major contributor to air pollution and reduced air quality being the largest environmental risk to premature mortality. This dissertation addresses that gap by advancing understanding of the air-quality related health impacts of US food in three ways: (i) by examining air-quality related health impacts of individual foods and diets, I find that 80% of the 15,900 annual death from food-related fine particulate matter is attributable to animal source foods; (ii) by estimating the air-quality related health impacts of pork and chicken along 79 company-specific supply chains, I find that the associated air-quality related health damages are concentrated in a small fraction of the total companies and the slaughter facilities they operate; and (iii) by calculating the external costs linked to the air-quality related health impacts and climate impacts of individual foods, I find that total external costs of food production are comparable to the net cash income of the US farm sector. These findings can inform decisions of food producers, processors and distributors, policymakers, and the broader public interested in improving the health and environmental outcomes linked to the food we eat. Future work should explore the air-quality related health impacts of the food system at a global scale, examine the relationship between food’s air-quality related health impacts and other environmental impacts, and evaluate solutions with respect to broader social and environmental goals.
  • Thumbnail Image
    Item
    Analysis of Air Pollution Models in the context of Coupled Carbon and Air Pollution Benefits in Multi-scale Urban Systems
    (2019-08) Fang, Andrew
    Many subnational state and local governments have taken a leadership role in climate change mitigation through clean energy and climate action policies. Because the majority of carbon emissions come from the burning of fossil fuels, there is potential for ancillary co-benefits of carbon mitigation resulting from the concurrent reduction of co-pollutants. This research focuses on the co-benefit of reducing particulate matter, which globally contributed to 4.2 million premature moralities in 2015. Global cities are simultaneously taking action to improve air quality and mitigate climate change by reducing emissions from energy and infrastructure systems. Cities are uniquely positioned to achieve improved environmental policy by managing carbon, air pollution, and health co-benefits concurrently due to the concentration of people and economic activity in cities. By accounting for the air pollution co-benefits of carbon mitigation, cities may create more political support for reducing emissions and energy use due to the large health benefits of reducing local air pollution exposure. The following dissertation explores these issues to determine how the state-of-the-science tools can be used to inform carbon mitigation actions which have air pollution and health co-benefits. Together, these chapters seek to inform the discussion surrounding the distribution of air pollution and carbon co-benefits in order to design more optimal environmental policies moving forward. The focus of this dissertation is on developing methods for the spatial analysis of air pollution co-benefits across multi-scale urban systems to support their evaluation in the context of carbon mitigation actions.
  • Thumbnail Image
    Item
    Data and code for "Design and evaluation of a low-cost sensor node for near-background methane measurement"
    (2023-11-20) Furuta, Daniel CR; Wilson, Bruce N; Presto, Albert; Li, Jiayu; furut011@umn.edu; Furuta, Daniel CR
    Cleaned data and supporting code for "Design and evaluation of a low-cost sensor node for near-background methane measurement". The data was collected at two research sites in 2022 and 2023, and the analysis code was used to generate the model and figures in the paper.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Simulating ozone effects on forest productivity: Interactions among leaf-, canopy-, and stand-level processes
    (1997) Ollinger, Scott V; Aber, John D; Reich, Peter B
    Ozone pollution in the lower atmosphere is known to have adverse effects on forest vegetation, but the degree to which mature forests are impacted has been very difficult to assess directly. In this study, we combined leaf-level ozone response data from independent ozone fumigation studies with a forest ecosystem model in order simulate the effects of ambient ozone on mature hardwood forests. Reductions in leaf carbon gain were determined as a linear function of ozone flux to the leaf interior, calculated as the product of ozone concentration and leaf stomatal conductance. This relationship was applied to individual canopy layers within the model in order to allow interaction with stand- and canopy-level factors such as light attenuation, leaf morphology, soil water limitations, and vertical ozone gradients. The resulting model was applied to 64 locations across the northeastern United States using ambient ozone data from 1987 to 1992. Predicted declines in annual net primary production ranged from 3 to 16% with greatest reductions in southern portions of the region where ozone levels were highest, and on soils with high water-holding capacity where drought stress was absent. Reductions in predicted wood growth were slightly greater (3–22%) because wood is a lower carbon allocation priority in the model than leaf and root growth. Interannual variation in predicted ozone effects was small due to concurrent fluctuations in ozone and climate. Periods of high ozone often coincided with hot, dry weather conditions, causing reduced stomatal conductance and ozone uptake. Within-canopy ozone concentration gradients had little effect on predicted growth reductions because concentrations remained high through upper canopy layers where net carbon assimilation and ozone uptake were greatest. Sensitivity analyses indicate a trade-off between model sensitivity to available soil water and foliar nitrogen and demonstrate uncertainties regarding several assumptions used in the model. Uncertainties surrounding ozone effects on stomatal function and plant water use efficiency were found to have important implications on current predictions. Field measurements of ozone effects on mature forests will be needed before the accuracy of model predictions can be fully assessed.
  • Thumbnail Image
    Item
    Simulating ozone effects on forest productivity: Interactions among leaf-, canopy-, and stand-level processes
    (1997) Ollinger, Scott V; Reich, Peter B
    Ozone pollution in the lower atmosphere is known to have adverse effects on forest vegetation, but the degree to which mature forests are impacted has been very difficult to assess directly. In this study, we combined leaf-level ozone response data from independent ozone fumigation studies with a forest ecosystem model in order simulate the effects of ambient ozone on mature hardwood forests. Reductions in leaf carbon gain were determined as a linear function of ozone flux to the leaf interior, calculated as the product of ozone concentration and leaf stomatal conductance. This relationship was applied to individual canopy layers within the model in order to allow interaction with stand- and canopy-level factors such as light attenuation, leaf morphology, soil water limitations, and vertical ozone gradients. The resulting model was applied to 64 locations across the northeastern United States using ambient ozone data from 1987 to 1992. Predicted declines in annual net primary production ranged from 3 to 16% with greatest reductions in southern portions of the region where ozone levels were highest, and on soils with high water-holding capacity where drought stress was absent. Reductions in predicted wood growth were slightly greater (3–22%) because wood is a lower carbon allocation priority in the model than leaf and root growth. Interannual variation in predicted ozone effects was small due to concurrent fluctuations in ozone and climate. Periods of high ozone often coincided with hot, dry weather conditions, causing reduced stomatal conductance and ozone uptake. Within-canopy ozone concentration gradients had little effect on predicted growth reductions because concentrations remained high through upper canopy layers where net carbon assimilation and ozone uptake were greatest. Sensitivity analyses indicate a trade-off between model sensitivity to available soil water and foliar nitrogen and demonstrate uncertainties regarding several assumptions used in the model. Uncertainties surrounding ozone effects on stomatal function and plant water use efficiency were found to have important implications on current predictions. Field measurements of ozone effects on mature forests will be needed before the accuracy of model predictions can be fully assessed.
  • Thumbnail Image
    Item
    Three Essays on the Impacts of Climate Change
    (2022-07) Djoumessi Tiague, Berenger
    In this dissertation, the focus is on the impacts of natural disasters and extreme air pollution on household and individual welfare as well as mitigative strategies. In Chapter 1, I study the impacts of large-scale floods in Tanzania on households’ value of crop production, income, expenditures, and life satisfaction. I use three-year nationally representative panel microdata from Tanzania combined with satellite flood data and I analyze the impacts of the shocks using a kernel weighting difference-in-differences approach. I find a 34 percent decrease in the value of crop production for households living in affected villages or clusters two years after the shocks. I find no effects on total expenditures or child nutrition, but a significant negative effect on self-employment income and a persistent decrease in life satisfaction. Finally, access to safety nets or transfer income, and to forest in a village appears to have important mitigating effects. In chapter 2, I look at how women outcomes (i.e., intimate partner violence, fertility preferences) and children’s outcomes (i.e., mortality and nutrition) are affected after households across Sub-Saharan Africa get exposed to large floods. Combining nationally representative Demographic and Health Surveys with satellite flood data, I find that women living in flooded clusters experience an overall decline in emotional violence by 0.04 percentage points, but no effect on physical violence from their partner. Fertility preferences change as women decrease their ideal number of kids by 5.3%. Child mortality also increases but only for children that are 6 months old or less. The results across subgroups show that only the poorest households experience an increase in physical violence, as well as when both partners work in agriculture. The drop in fertility preferences is concentrated among women with little to no education. The decrease in female economic empowerment, increase in partner’s alcohol consumption, and household wealth appear to be important mediating factors. The results should be taken with caution given the violation of parallel pre-trends and the presence of heterogeneous treatment effects. Chapter 3 investigates another type of environmental shock, air pollution. I estimate the effects of exposure to ambient air pollution on daily health-related behaviors, weekly labor supply, and productivity at the workplace among US individuals. Using an individual fixed-effects regression approach, I examine how daily changes in outdoor air quality influence the time spent on daily health-related activities. I find that only when the air quality index becomes very unhealthy or hazardous, there is a 21% decrease in the minutes spent on outdoor sports and exercise activities, and a 260% increase in minutes spent watching TV. The increase in physical inactivity can have long-term negative health consequences. I also implement an instrumental variable (IV) strategy using wind direction and atmospheric boundary layer height as exogenous shocks to satellite-based aerosols to understand how changes in air pollution affect weekly labor supply and productivity. I find that increase in the total aerosol optical depth (AOD) leads to no overall change in labor supply decisions, both on the decision to go to work and the weekly worked hours. There are also no overall significant effects on labor productivity proxied by weekly earnings. The effects across subgroups also suggest differential effects in avoidance behaviors across the income distribution, age groups, occupations, race, and ethnicity, especially when the air quality is very unhealthy or hazardous.