Similar term(s): Nitric oxide (NO), nitrogen dioxide (NO2).
NOx is the generic term for a group of highly reactive gases, all
of which contain nitrogen and oxygen in varying amounts [such as
oxide (NO) and
nitrogen dioxide (NO2)].
Many of the nitrogen oxides are colorless and odorless. However, one common
pollutant, nitrogen dioxide (NO2) along with particles in the air can often be
seen as a reddish-brown layer over many urban areas.
Nitrogen oxides form when fuel is burned [...]. The primary sources of NOx are
motor vehicles, electric utilities, and other industrial, commercial, and
residential sources that burn fuels.
In the atmosphere, nitrogen oxides can contribute to formation of
photochemical ozone (smog) and have health consequences. They also lead to acid
rain and contribute to global warming.
Nitric oxide (NO) is the most common form of
nitrogen directly emitted into the atmosphere.
In ambient outdoor air, nitric oxide (NO), which is emitted by motor vehicles,
combines with oxygen in the atmosphere under the action of sunlight, producing
nitrogen dioxide (NO2) -a major air
pollutant- and other NOx.