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Nitrogen Dioxide

What is it?
Nitrogen Dioxide (NO2) is one of a group of highly reactive gases
known as oxides of nitrogen or nitrogen oxides (NOX). Other nitrogen oxides include nitrous acid and nitric acid. The Environmental Protection Agency (EPA) uses NO2 as the indicator for the larger group of nitrogen oxides. High levels of NO2 can be seen as a reddish-brown layer over urban areas. 

Where does it come from?
NO2 primarily comes from the burning of fuel. Some of these include industrial, commercial, residential sources, and during the combustion process in on-, off- and non-road vehicles. 

How is it harmful?
NOX and volatile organic compounds (VOC), in the presence of sunlight, forms the photochemical pollutant Ozone.  This secondary pollutant along with NOX can be transported over long distances; thereby, not only affecting areas where the pollutants are emitted but outlying areas as well.  For this reason, it is important not to consider an isolated area when attempting to decrease the emissions of the pollutant..

Other potential problems from the emission of NOX include acid rain, water quality deterioration, and an increase in particulate matter and toxic chemicals in the air.  These factors are harmful to both animal and plant life.

What’s being done to help?
EPA currently has an annual standard for NO2 set at 53 parts per billion (ppb) for the annual standard, and 100 ppb (98th percentile, average over three years), for the one-hour standard.  These standards are subject to change as updated scientific information is obtained on the affects of this pollutant on human health.

Regional Matters:
Various projects and programs are continuously being developed to decrease the NOx emissions throughout North Central Texas.  Some of these include:

The ten-county region of North Central Texas, along with the entire state, has never exceeded the national standard set by the EPA.  Despite that fact, NO2 and NOX are monitored closely in the region, measured at 15 monitors, as they are a major contributor to the formation of ozone.

4/24/2018 JPL/MG %Trans

 North Central Texas Council of Governments | 616 Six Flags Drive P.O. Box 5888 Arlington, TX 76005-5888
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