A Short Note on Nitrogen Dioxide

Nitrogen dioxide or also called NO2 is a  pollutant in its gaseous form which is mainly composed of nitrogen and oxygen particles and is one of a group of related gases called nitrogen oxides, or NOx. The formation of NO2 takes place when there is a burning of fossil fuels such as coal, oil, gas, or diesel at high temperatures. NO2 and other nitrogen oxides act as the outdoor air contributing or reason for this rising risk of particle pollution and also as a risk to the chemical reactions that produce the ozone. 

Nitrogen dioxide is one of six air pollutants that are spread widely and that need national air quality standards to limit their use and production in the outdoor air. NO2 can also be produced indoors when natural fossil fuels like wood or natural gas are burned inside. 

Health Effects of NO2

Nitrogen dioxide is prepared by thermal decomposition of metal nitrates, thus inhaling air with a high concentration of NO2 can irritate airways during the passage of the human respiratory system. Such contact and Clash of  NO2 over short periods can increase the risk of respiratory diseases, diseases such as asthma, which leads to respiratory symptoms such as coughing, wheezing, or difficulty breathing, this increasing symptoms and risk always lead to hospital admissions and visits to emergency rooms. 

However, longer exposures to an increased concentration of NO2 may result in the development of permanent asthma and also gradually increase the causes to form respiratory infections. 

Patients suffering from asthma, as well as children and also the aged, are generally at greater risk for the health effects of NO2. However, sometimes NO2 along with other NOx tends to react with other chemicals in the air to form both particles known as matter and ozone. Both of these particles (matter and ozone) are also quite harmful when inhaled due to their effects on the respiratory system.

Due to some recent review of the health effects of air pollution due to NO2 by a  working group of WHO known as Review of Evidence on Health Aspects of Air Pollution REVIHAAP. This workgroup arranged by WHO evaluated and observed the most recent studies on long-term exposure to NO2 and for both the cases: natural (non-accidental)/total or cause-specific mortality. 

Now the question arises that whether NO2 is directly responsible for the health effects or as Nitrogen dioxide is a reddish-brown toxic gas it is only an indicator of other pollutants that are specifically considered as toxins including both particulate matter and specific constituents for example metals, polycyclic aromatic hydrocarbons, and other organic matter.

Environmental Effects of NO2

To cause a hazardous effect on the environment NO2 and other NOx interact and react with components like water, oxygen, and other chemicals in the atmosphere to form acid rain. Acid rain causes rain with such toxic components in its droplets that it harms sensitive ecosystems such as lakes and forests. 

This nitrogen dioxide gas has characteristics sharp, biting odour and is a prominent air pollutant that’s why when NOx interacts with nitrate particles present in the environment, it makes the air hazy and quite difficult or invisible to see through it. This affects the many national parks that we visit for the view. The presence of NOx in the atmosphere provides an amount of nutrient pollution in coastal waters. All these pollution measuring standards are designed to protect sensitive individuals for example children and asthmatics. 

However, typically nitrogen dioxide present outside in the atmosphere levels are all below the particular 1-hour standard and at these levels, the levels do not usually increase respiratory symptoms.

The recommended air quality standards for nitrogen dioxide are:

• 0.12 parts per million (ppm) for a 1-hour exposure period
• 0.03ppm for an annual exposure period.

What are the Respective Measures to Reduce NO2 Pollution?

During a survey, EPA’s national and regional rules to reduce emissions of NO2 and NOx will be helping state and local governments to greatly extend to meet the known National Ambient Air Quality Standard (NAAQS). EPA also identifies such areas where the air quality does not meet the standards of national NO2 standards. To inspect these particular areas, state, local, and tribal governments make plans to reduce the amount of NO2 in the air. Following are the points to reduce the concentration of nitrogen dioxide pollution –

1. Make sure that gas appliances are properly turned off and always use exhaust fans to vent the gas outdoors.
2. To Make sure in kerosene space heaters we use the proper fuel.
3. Prefer vented space heaters over the unvented ones.
4. To Open every vent area or window when a fireplace or wood-burning stoves are in use.

Conclusion

Vehicles like cars, trucks, and buses, are the largest sources of nitrogen dioxide emissions, further followed by releases from power plants diesel-powered heavy construction equipment, some other movable engines, and industrial boilers. During a study or survey in the U.S., there was an emission of 14 million metric tons of nitrogen oxides caused due to man-made resources, this gradual increase in emission mainly took place from burning fuels, in 2011. 

Nitrogen dioxide is prepared by the thermal decomposition of metal nitrates. There are a total of 5 Emissions of nitrogen dioxide that will be declined as an initiative to clean up many of these sources in upcoming future years.