what do you need help with exactly?
Site control zones are established to prevent people from entering contaminated or hazardous areas. For example, there are site control zones in Ebola tents. Assuming you are talking about something like a nuclear waste spill or such, they would be established to prevent people from getting radiation sickness or further destruction of cells.
The Diaphragm aids respiration by moving up and down. During inspiration it moves down and increases the volume of the thoracic cavity, during expiration it moves up, decreasing the volume
