Nitrogen dioxide can irritate the lungs and lower resistance to respiratory infection. People with respiratory problems such as asthma and bronchitis, as well as children and the elderly, are particularly at risk.
NO2 chemically transforms into nitric acid, which, when deposited as acid rain, contributes to lake acidification and harms aquatic ecosystems. It can also damage trees and crops, resulting in substantial environmental losses.
When NO2 undergoes a chemical transformation in the atmosphere, it becomes a component of ground-level ozone and smog. Exposure to smog impairs lung function in the short term and accelerates deterioration in lung function over the long term.