This dissertation mainly focuses on agricultural policies, water pollution and human health. Chapter.2 examines the causal impact of agricultural water pollution on individual health outcomes. The findings suggest that agricultural water pollution worsens health outcomes and these adverse health effects appear to be largely due to contaminated drinking water. Chapter.3 explores both of the intended wealth effect and unintended pollution effect on human health caused by Chinaβs agricultural support polices. I find that although the income effect dominates on reducing the overall sickness, the pollution effect is more substantial on the diarrhea incidence and adult BMI. Income affects slightly higher than pollution on adults\u27 overall health, while pollution has higher impacts on children\u27s overall health. Chapter.4 builds a dynamic optimization model internalizing the health cost of agricultural water pollution. My simulation results suggest that policymakers should manage fertilizer application rates based on the initial nitrate concentration levels
