![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20081110191721im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Chief Causes for Concern
Nitrogen Oxides
NOx
- is one of the main ingredients involved in the formation of ground-level ozone, which can trigger serious respiratory problems.
- reacts to form nitrate particles, acid aerosols, as well as NO2, which also cause respiratory problems.
- contributes to formation of acid rain.
- contributes to nutrient overload that deteriorates water quality.
- contributes to atmospheric particles, that cause visibility impairment most noticeable in national parks.
- reacts to form toxic chemicals.
- contributes to global warming.
NOx and the pollutants formed from NOx can be transported over long distances, following the pattern of prevailing winds in the U.S. This means that problems associated with NOx are not confined to areas where NOx are emitted. Therefore, controlling NOx is often most effective if done from a regional perspective, rather than focusing on sources in one local area.