Occupational Lung Diseases

A disease associated with prolonged exposure to silica dust during glass production, characterized by classic X-ray findings of calcified lymph nodes and pleural involvement, is most likely what disease?

A 50 year old male presents with fever and malaise for 4 months and pain in the knees and ankles. Blood tests are normal apart from a raised ESR. Chest x-ray shows bilateral hilar adenopathy and pulmonary infiltrates most severe in the upper and mid zones. Mantoux test is negative. What is the most likely diagnosis?