Review : Nitrogen Dioxide: Causation and Aggravation of Lung Diseases

It is of great importance to investigate the role of air pollutants in causing and aggravating lung diseases. The levels of concentration of some of these com bustion products have shown a decreasing emission curve, but the emissions of nitrogen dioxide (NO2) are still increasing. Most of the NO2emissions origi nate from road traffic. The installation of catalytic converters may well change this. It is established that low concentrations of NO2affect the respiratory system; this is especially obvious in asthmatics. Regarding long-term effects, it is believed that high levels of NO2may cause an increased frequency of respi ratory illness, but it is not possible to confirm this suspicion completely.