Neck and back pain from so much sitting, carpal tunnel from so much tapping away at a keyboard, and the danger of going spontaneously insane from the isolation and leaping hysterically from your window. (It's okay—you work on the first floor, but still. Get a hold of yourself.)
Aside from that, no physical danger. Even if you spend all day listening to exploding artillery shells and detonating hand grenades, you are safe inside your little black room.