Most of the workers are protected, and there is no dust. When the accumulated so may prevent this serious disease is becoming more and more strong. It's a good idea to have a way to prevent that is how.
Most people work Get dusty and unprotected. When retained indefinitely May make the disease more serious than this. It should be a way to protect the right way.
Most of the workers were dust and no defense, when accumulated over time. May cause more serious disease. Therefore, there should be how to prevent properly.