Nitric oxide: a non-invasive measure of silica induced health effects and its potential role in silica induced effects

Abstract

Although standards of industrial hygiene have improved markedly over the past 30 years, silica remains the major cause of occupational interstitial lung disease. The diagnosis of silica-induced diseases is mainly based on clinical findings, lung function and X-Ray examinations. None of these are sensitive to early stage disease or subtle progression. There is a need to find an alternative to remedy the above shortcomings. Great efforts have been made in investigations of exhaled nitric oxide (eNO) as a marker of various diseases and the possible causal pathways for NO to contribute to the diseases, whereas little research is available to elucidate the possibility of eNO as a non-invasive alternative to reflect silica-induced harmful effects. This review focuses on whether eNO can be used as a screening measure of silica-induced harmful effects and whether the role of NO in silica-induced lung reactions is at an initial stage. It is concluded that further research is warranted to testify the feasibility to use eNO and NO derivatives in sputum as a non-invasive screening tool for silica related disorders. In addition, better understanding of NO in silica-induced harmful effects might benefit both prevention and treatment of silica related occupational lung diseases.