The lathe worker is the most tired when machining threads, because it will be more tired to keep a posture all the time. After work, you should exercise your waist and neck, massage your knees and feet to avoid joint diseases. Its purpose is to carry materials for your own use. Dirty is mainly lubricating oil and sludge, but if you pay attention to cleaning and maintaining your own equipment, the problem is not big. There will be some dust when sharpening the knife. You'd better wear a mask. After sharpening the knife, blow or dust it with compressed air, and then take off the mask.