A noxious odor on an A319 prevented a flight crew from preflighting the aircraft so the flight was canceled. The Lead Flight Attendant discovered the odor in first class and the Captain became ill after smelling it while verifying the Leads opinion.

Narrative

Upon entering the RON Airbus; I went in the cockpit to perform SAFETY and POWER ON checklist; and I heard the Lead Flight Attendant exclaim there was a noxious odor in first class cabin and she asked me to come quickly. Aft of the main entry door the smell was extremely foul; I told the flight attendants to leave the aircraft. I exited and started to dry heave from the smell; and went to the podium and advised the agent that I needed to call Maintenance. I entered the write up in the logbook and advised Maintenance. I returned to the plane and tried turning OFF ground air; turning on packs; open doors to air it out. The odor dissipated about 50% but changed to a chemical smell. I noted that there was the hot air valve on MEL. I filled out the air quality form and we were dead headed out leaving it for Maintenance to discover the reason for the noxious fume and odor. More training is needed for handling fumes/odors of unknown source. We all were exposed only for seconds but we were all concerned about health ramifications. The Lead felt she had a headache; but no medical attention was required; and I had a slight headache and metallic taste but probably was from dry heaving after smelling the stench.