An A320 Captain reported the two aft Flight Attendants were light headed with an oily taste in their mouths during preflight. The flight continued to the destination where the symptoms continued after flight.

Narrative

On push back from the gate and before engine start Flight Attendant C called the flight deck to advise us there was a odor in the aft galley. I inquired as to how they were feeling and if any of the passengers were experiencing the same effects. No passengers complained of the odor. I asked the flight attendants if they were feeling OK to perform their duties and both Flight Attendants B and C agreed to depart. During the course of the flight Flight Attendant C called the flight deck to give us info on how they were feeling; a little light headed and bad taste in their mouths and asked if we had an air quality report to fill out when we landed. We ACARSed maintenance and reported the problem and also wrote it up in the logbook. Upon arrival maintenance brought out the required report and I filled it out to the best of my ability with the help of Flight Attendants B and C. We checked on Flight Attendants B and C as to how they were feeling after the flight and told us they still were feeling light headed and bad taste in their mouth. We are not sure of the event occurrence; possibly an APU oil leak into the bleed system but that would be a maintenance conclusion to what they found on the aircraft after a formal inspection. A flow chart as to what steps the flight crew should follow in the event this occurs in the future [would be helpful]. Something like the RNAV or Deicing/Anti-icing flow charts that we presently use to help the flight crews get a better handle on the final outcome that will keep US all in the loop to provide a safe work environment for all crew members on the aircraft.