dissenting.
I respectfully dissent. On this record the finding that the employee is permanently totally disabled solely due to his non-work related lung disease is manifestly contrary to the evidence. Dr. Brodsky, an orthopedist, and Dr. Mulrooney, a specialist in lung diseases, the two medical experts who considered both employee’s back injury and his lung disease in giving their opinions, concluded that employee was totally disabled by the combination of his disabilities. Dr. Mulrooney attributed 20% of the responsibility to the back injury. Even though both specialists expressed the view that employee would be able to work if he had only his back injury and back impairment, this fact does not reasonably lead to an inference that the back injury has no part in his present disability. The evidence is that employee’s pulmonary function tests did not change significantly over the past several years, yet he continued to work in spite of his lung disease until he suffered the back injury. Both employee’s back injury and his lung disease were substantial contributing factors in his disability. Therefore, employee is entitled to compensation because the back injury was compensable. Schaefer v. Dunwoody Industrial Institute, 280 N.W.2d 35 (1979).