i would say the most pressing health and safety issue at computers is POSTURE. this is implications in ergonomics, muscle strain, muscle alignment, back and neck pain, wrist and arm strain, keyboard and mouse placement, eye strain, monitor placement and brightness, relative room lighting, and a few more things.
=EDIT= oh, food and drink safety issues? wtf. yea, don't spill your sugary death drink on the keyboard. god forbid