This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hospital waste and disaster management, Occupational health, Subject name: Social & Preventive Medicine
[{'content': 'Respirable dust, responsible for pneumoconiosis, has a size limit of: \nSelect and explain. \nA. <1 micron, B. <5 micron, C. <10 micron, D. <100 micron', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pneumoconiosis occur due to occupational exposure to dust. Paicles size 0.5 to 3.0 microns are the most dangerous (as a health hazard causing pneumoconiosis), as they reach the interior of lungs with ease. Paicles size and behaviour: Paicle size Behaviour >10 microns Settle down by gravity <10 microns Remain suspended in air 5-10 microns Arrested in upper respiratory tract 3-5 microns Deposited in mid respiratory tract 1-3 microns Enter alveoli and settle there (cause pneumoconiosis) <1 more Brownian movement Ref: Park 25th edition Pgno: 843', 'role': 'assistant'}]