wavelength waveÂ·length (wÄv'lÄngkth', -lÄngth') n. Symbol Î» The distance between one peak or crest of a wave of light, heat, or other energy and the next corresponding peak or crest.
Causes: Emphysema: The number one cause of emphysema is smoking. Other contributing factors in its development or exacerbation (increase in severity) include long-term exposure to other lung irritants, such as air pollution, chemical fumes, or dust.
Here are some key points about emphysema. More detail and supporting information is in the body of this article. 1  Most cases of COPD, and therefore emphysema, are caused by cigarette smoking. 2  Emphysema is rarely caused by a congenital condition known as Î±1-antitrypsin deficiency, for which there is a lab test.