- The Japanese Society for Hygiene
- 日本衛生学雑誌 (ISSN:00215082)
- vol.26, no.3, pp.304-314, 1971-08-28 (Released:2009-02-17)
Nitrogen dioxide is one of the main atmospheric pollutants in many communities. It is emitted in large quantities in the exhaust of automotive engines and is formed when atmospheric nitrogen and oxygen are heated to a high temperature in a flame.Experiments were made to ascertain possible synergistic effects of nitrogen dioxide and influenza virus infection in mice. Young female dd strain mice weighing 15 to 17g were challenged with mouse-adapted type A influenza virus, strain PR 8, two hours after acute and intermittent exposure to 10ppm nitrogen dioxide for two hours daily for one, three and five days. Female I.C.R. strain mice weighing 22 to 25g were also challenged with type A influenza virus after continuous exposure to 0.5 to 1.0ppm nitrogen dioxide for 39 days.Results were as follows;1) Acute and intermittent exposure to 10ppm nitrogen dioxide for two hours daily for five days significantly increased the susceptibility of mice to influenza virus infection as demonstrated by enhanced mortality.2) Extent of interstitial pneumonia was higher in the mice challenged with influenza virus after chronic and continuous exposure and acute and intermittent exposure to nitrogen dioxide than in the infected controls.3) Adenomatous proliferations of bronchial and bronchiolar epithelium were marked in the mice challenged with influenza virus after continuous exposure to low levels of nitrogen dioxide.