Nitrogen oxides, or Nox, are formed in the atmosphere from the breakdown of nitrogen gas. Nitrogen gas is very difficult to breakdown, therefore only specially developed bacteria and the heat from car exhaust can release nitrogen oxides. Nitrogen oxides are harmful to the environment because in the presence of sunlight, Nox can form ozone at the Earth’s surface. Other negative effects of nitrogen oxides include acid rain, low water quality, and an increase in toxic chemicals in the air.
These factors are also harmful for plant and animal life. Perhaps nitrogen oxides are not at a high level in the United States due to the increase in alternative fuel cars and by using alternative gases that produce less exhaust. Sulfur oxides can be naturally found in volcanoes and hot springs. Human sources of sulfur oxides include the burning of coal, the smelting of metals, and also from electric power companies. Sulfur oxides are harmful on the respiratory system and can cause acid rain.
The release of sulfur oxides may not be high in the United States due to the implementation of fuel quality standards, less vehicle emission, and promoting fossil fuels. Carbon dioxides can be found from volcanoes, car exhaust, factories, power plants, and decaying plants and animals. Carbon dioxide releases greenhouse gases in the atmosphere (which deteriorate the ozone), can contribute to acid rain, and contributes to smog. Carbon dioxide levels may be low in the United States due to an increase in plant life (which uses carbon dioxide), and limits or regulations set on car exhausts and the promotion of fossil fuels.