What was found
AIR QUALITY EVENT DURING CRUISE .PERSISTENT MUSTY SMELL ON THE BACK OFTHE AIRPLANE.MULTIPLE PAX SICK.-T/S IAW TSM 05-50-00-810-831-A FOR CAUSE OF CABIN ODOR OR SMOKE. COMPLETED APU AND ENGINE RUNS WITH NO EVIDENCE OF LEAKS OR ODORS AT THIS TIME. IAW AMM 71-00-00 PERFORMED DECONTAMINATION OF ECS (PACKS) IAW AMM 21-00-00-615-002. R & R RECIRCULATION FILTERS IAW AMM 21-21-41. ALL SYSTEMS OP CK GOOD. A/C OK TO RETURN TO SERVICE.