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What is Minimum duration of developing coal miners pneumoconiosis is - and explain in detail?
- The coal miners pneumoconiosis has two phases; first phase is simple pneumoconiosis which is associated with little ventilatory impairment. - this phase may require about 12 years of work exposure for its development. - second phase is characterized by progressive massive fibrosis Reference: Park's textbook of preventive and social medicine, 23rd edition, pg no:806 <\p>