The dangerous particle size causing pneumoconiosis varies from:: (A) 100-150 um, (B) 50-100 um, (C) 10-50 um, (D) 1-5 um
Answer is D. Ans. (d) 1-5 um(Ref: Robbins 9th/pg 689; 8th/pg 697)For pneumoconiosis, the most dangerous particles are from 1 to 5 um in diameter, because particles of this size may reach the terminal small airways and air sacs and settle in their linings.