Nitrogen dioxide NO₂

Nitrogen dioxide belongs to the group of highly reactive nitrogen oxides (NO_x).Nitrogen oxides are produced by high temperature fuel combustion, primarily from transportation sources (cars, ships, heavy machinery, etc.) but also during energy production. A less important source is the anaerobic digestion of fresh organic material. NO₂ represents only 5-10% of directly emitted nitrogen oxides, the remaining amount is NO. However, the cooling of the exhaust and the delivery of oxygen conduces to oxidation of NO to NO₂. Nitrogen oxides and other compounds in the atmosphere are involved in chemical changes leading to the formation of particulate matter and ozone.

Significance to the environment and human health:

Health effects of exposure to NO₂:

Short-term exposure to high concentrations of NO₂ can lead to:

• irritation of the respiratory tract;
• exacerbation of respiratory diseases, especially asthma, leading to respiratory symptoms (such as cough, wheezing or difficulty breathing);
• increase in hospitalization and visits to reception rooms;
• chemical inflammation and pulmonary edema caused by the reaction of NO₂ with body fluids and the formation of nitrous and nitric acid;
  
  
  

Prolonged exposure to elevated NO₂ concentrations may:


• contribute to the development of asthma, increase susceptibility to respiratory infections (bacterial and viral);
• weaken lungs defenses;
• contribute to increased mortality in asthmatic patients as well as in children and the elderly who are in risk groups;

Environmental effects of exposure to NO₂:

• reacting with water it creates nitrous and nitric acid, acid rains elements, destructively affects forest ecosystems, water reservoirs;
• in reactions with hydrocarbons it leads to the formation of ozone and other harmful oxidizing compounds;
• nitrate aerosols limit visibility, reduce the inflow of solar radiation;

Elaborated by A. Drzeniecka-Osiadacz

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nitrogen dioxide NO2