What air pollutants do power plants produce?

Nuclear power plants only emit water vapor. However, all of the Uranium must be transported to the plant, and all of the spent fuel rods have to been shipped by rail for underground storage. Coal fired power plants emit carbon dioxide, water vapor, Mercury, and sulfur dioxides. Hydroelectric power plants do not generate any emissions, however the damming of a river leads to the loss of large areas of wetlands and old growth forest. Natural gas power plants emit carbon dioxide, water vapor, and nitrous oxides.