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.
Risk Factors for Emphysema. 1  Cigarette smoke is by far the most important factor in the development of emphysema and COPD. 2  About 2% of cases of emphysema are due to hereditary deficiency of the alpha-1 antitrypsin gene.