Can silent reflux cause can acid reflux cause pulmonary fibrosis or COPD orlung cancer?

Not usually. Acid reflux affects the esophagus and, at times, the upper respiratory passage(larynx, trachea) but i wouldn't expect pulmonary fibrosis or lung cancer as complications. If you have reflux, see your md for treatment and dietary advice in order to protect your esophagus from chronic changes.