Interesting that contamination in the air supply of the 146/RJ, is still an emotive issue, as it should be , after all this time. And it would appear to be still unsolved.
I flew the 146/RJ for 10 years, including Australian registered ones. On some aircraft there was a definite smell of oil or dirty socks if you prefer. The usual fix from the engineers, was " pack cleaned, tested and found servicable" But more often than not, the smell returned.
During the period that I flew the 146/RJ, I cannot recall feeling unwell.
However three years later my medical was withdrawn by the CAA, and that was the end of my flying career. After 34 years of flying all round the world, I was forced to retire, at the tender age of 53. And the reason - I was diagnosed with Parkinson's Disease . My PD nurse said it could be that breathing contaminated air, for all those years could have acted as a trigger , to the Parkinson's - who knows. But how to prove it, now that is another matter entirely.