A chest x-ray of a patient with nitrogen oxide poisoning shows corn-like shadows all over both lungs. Nitrogen oxides (nitrogen oxides) include a variety of compounds, such as nitrous oxide (N2O), nitric oxide (N0), nitrogen dioxide (NO2), nitrous oxide (N203), nitrous oxide (N204) and nitrous oxide (N205). In addition to nitrogen dioxide, all other nitrogen oxides are extremely unstable and become nitrogen dioxide and nitric oxide when exposed to light, moisture or heat, and nitric oxide becomes nitrogen dioxide. Therefore, the occupational environment is exposed to a mixture of several gases often called nitrous fumes (gas), mainly nitrogen oxide and nitrogen dioxide, and mainly nitrogen dioxide. The main points of the diagnosis of two lungs covered with corn-like shadows: 1, occupational history (or medical history) of inhalation of nitrogen oxides. 2.After an incubation period of a few hours to 72h after exposure to toxicants, clinical manifestations characterized by chemical bronchitis, pneumonia and pulmonary edema occur. 3, Chest X-ray is consistent with the performance characteristics of irritant pulmonary inflammation or pulmonary edema. 4.Blood gas analysis results, showing reduced partial pressure of arterial blood oxygen.