Yer pretty safe in a Nomad. Its ACMs (Air Cycle Machines) are of the non-existent variety, which prevents contaminated bleed air being pumped into the cabin.
Smart designers at the GAF to foresee such a problem.
EchoNovemberTango,
As best I recall the problem with the 146 air quality was eventually traced to #1 bearing seal, which despite many re-designs, kept failing to properly seal.
In the late 90's a method of designing a seal then testing it on a test bed, as opposed to in an in-service engine, was developed. Unlike other seals before it, this one was successful in eliminating/reducing the ingress of fumes.