I think that you will find this is the subject of an older thread and that the significant safety issues have been dealt with.
BAe146 operators were sent several All Operators Messages explaining the situation, commencing cica 1999. Corrective action is either in hand or complete; details are available via Service Information Leaflets from SIL 21-45, Nov 2000 and up-issues thereafter.
The CAA issued FODCOM 17/2000. Also see the main CAA report here
CAA PAPER 2004/04 Cabin Air Quality