Air pollution is one of the most important environmental threats to urban populations and while all people
are exposed, pollutant emissions, levels of exposure, and population vulnerability vary across
neighborhoods. Exposures to common air pollutants have been linked to respiratory and cardiovascular
diseases, cancers, and premature deaths. These indicators provide a perspective across time and NYC
geographies to better characterize air quality and health in NYC.
Nitrogen dioxide, or NO2, is a
gaseous
air pollutant composed of nitrogen and oxygen and is one of a group of related gases called nitrogen oxides,
or NOx. NO2 forms when fossil fuels such as coal, oil, gas or diesel are burned at high temperatures. NO2
and other nitrogen oxides in the outdoor air contribute to particle pollution and to the chemical reactions
that make ozone. It is one of six widespread air pollutants that have national air quality standards to
limit them in the outdoor air. NO2 can also form indoors when fossil fuels like wood or natural gas are
burned.