My husband had several years exposure to sbestos while aboard ship in the military. The VA doctors agree that he was exposed to abestos and the latest report shows that the lung xrays (CXR) indicates pneumoconiosis,as seen with patients with exposure to abestos. However, my husband did smoke and the doctor reports that he can not determine which is the original issue of his COPD without resorting to speculation. His lung problems developed prior to 1955; however, we did nothing about it until he had to go to the ER as he was very ill. They found his oxygen level very low and his heart rate was very low as well. It is my understanding that pneumoconiosis from abestos developed in later years as his did and if the issue was caused by smoking it should have shown up years before. He quit smoking on November 17, 1980. He is on oxygen 12 hours daily and inhalers as well. My question is - how can we prove that his lung issues (pneumoconiosis) is caused by his exposure to asbestos and not smoking?