Bill was told he has start of emphysema and he's never smoked. they said scarring from child hood asthma. is there anything to slow progression?

Depends: this depends on how they determined if there really was emphysema or not. The term is sometimes used loosely and without evidence. You should see a pulmonary physician for a proper evaluation.

Aging lung changes: Some loss of air sacs in the lung with age alone occurs. This loss is called emphysema. Years of uncontrolled asthma at any age can damage the lung. Disorder called Alpha1 Antitrypsin where early in life emphysema is seen but unlikely cause here. Any chronic inhalation of smoke or chemical fumes can cause lung damage. Avoiding elements such as these and treating lung infections preserves the lung