Chronic Injury of Pulmonary Tissue in Submarine Cabin Environment

Submarine cabin contains very complicated air environment. Harmful gases in this environment may induce chronic inflammatory reaction and oxidant-antioxidant imbalance in the pulmonary tissues by stimulating bronchus epithelial cells and damaging pulmonary vascular endothelial cells. Increasing oxygen free radicals and inflammatory reactions may lead to changes in the levels of superoxide dismutase, endothelin-1, and nitric oxide in blood and lung tissues, and attract a large number of inflammatory cells and inflammatory mediators such as tumor necrosis factor-α and interleukin-6 which would infiltrate into lung tissues. These inflammatory reactions may lead to airway remodeling, pulmonary vascular smooth muscle proliferation, pulmonary vascular resistance increment, and pulmonary hypertension. At the same time, long-term inflammation can also cause pulmonary fibrosis, deteriorating lung function.