Density Map of Nitrogen Oxide Emissions 1997
Source: Environmental Protection Agency
Map Description:
This map depicts nitrogen oxide emissions by county in 1997. Nitrogen oxides play a major role in the formation of ozone in the atmosphere. A variety of nitrogen oxide compounds occur both naturally and as a result of human activities. Anthropogenic (i.e., man-made) emissions of nitrogen oxides account for a large majority of all nitrogen inputs to the environment. The major sources of anthropogenic nitrogen oxide emissions are automobiles and power plants. Natural sources of nitrogen oxides are lightning, biological and abiological processes in soil. Ammonia and other nitrogen compounds produced naturally are important in the cycling of nitrogen through the ecosystem.

Evidence suggests that long-term exposure to nitrogen oxides may lead to increased susceptibility to respiratory infection ad may cause alterations in the lung. Adverse environmental effects include the loss or shift in number and type of species, and explosive algae growth leading to a depletion of oxygen in the water, and/or an increase in levels of toxins harmful to fish and other aquatic life.

Cautions for this Product:
This map only provides a general overview and does not identify potential sources of air pollution.

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