In Helverson v. Workmen's Compensation Appeal Board (Central Foundry Company), 76 Pa. Commw. 286, 463 A.2d 1243 (Pa. Cmwlth. 1983), Herbert K. Helverson (Helverson) petitioned for benefits and alleged that he was permanently and totally disabled from silicosis as a result of exposure to airborne silica and other substances during the course of his twenty-five years of employment with Central Foundry Company (Central). Helverson amended his petition at the first hearing to include a claim for benefits because of disability caused by all occupational diseases within Section 108(n) of the Act, 77 P.S. 27.1. At issue was the nature and cause of Helverson's lung disease. His treating physician, Dr. Murray J. Miller, testified that Helverson was totally disabled by bronchitis superimposed on a chronic obstructive pulmonary disease that had been caused by his long environmental work history and that the chronic obstructive pulmonary disease was peculiar to his industry or occupation. Theodore Rodman, M.D. (Dr. Rodman) testified on behalf of Central and opined that Helverson was totally disabled as a result of chronic obstructive lung diseases. However, Dr. Rodman testified that the chronic obstructive lung diseases were caused by Helverson's cigarette smoking and were unrelated to his employment. The referee found Dr. Rodman credible and denied Helverson's petition. The Board affirmed. Helverson, 463 A.2d at 1244-1246.