As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, CREW AND PASSENGERS BEGAN COMPLAINING OF MILDEW SMELL AND EYE/THROAT IRRITATION. AS FLIGHT PROGRESSED SITUATION IMPROVED. A/C LANDED AT DESTINATION AIRPORT. MAINTENANCE FOUND APU OIL LEAK AT B-NUT ON TOP OF APU OIL PRESSURE SWITCH. B-NUT WAS TIGHTENED, AREA CLEANED AND RECIRCULATION FILTERS CHANGED.