ans. Most environmental considerations affect the performance of workers. There are different levels of influence. Some are barely noticeable, and have no tangible effects. Others are mild irritants. over long periods of time these can cause mental and physical stress. There are more severe irritants that will lead to discomfort or worse. These will reduce the effectiveness of the employee, to the point where the employee will be unable to work without aids and other support.
ans. Noise levels in a plant are typically measured while the machine is in operation in the intended environment to obtain the worst case noise level. The noise levels near the machine will be slightly higher because of the direct sound transmission. Noise levels throughout the room will have a basic level based on the reverberant component and the sound absorption in the room.