Slight thread creep; but in 90's I read a report commissioned by the LH & Alitalia pilot's union into cosmic radiation at >FL300. Evidently a German whose job was the monitoring of radiation in ground plants had travelled in a flight deck with a geiger meter and it went epileptic. The report was every extensive and quite scary. Perhaps it was meant to be. There are now developed 'exposure' models linked to rosters and the amount of time spent >FL300, so everything is OK. (a bit like the fatigue model linked to rosters). I wonder just how much actual data high level was accumulated before those models were designed, and how much was extrapolation and laboratory generated data. It disappeared very quickly into a
PR black hole and the unions didn't pursue it publicly; and ECA seems to have been very quiet on the issue.
Then the poisoned cabin air saga came to light and it too was poo poo'd as voodoo and pure speculation; until some scientific tests were done. But it too disappeared into a
PR black hole and the unions didn't pursue it publicly. Previously DVT went the same route.
All these were 'inconvenient truths'. The cure was far too difficult to implement so we better not acknowledge the problem and it will fall off the radar.
I remember the same thing with the 'lead in fuel' scare mongering; except that was pursued, proven and corrected. I guess that was an easy affordable solution so it was easier to keep the campaign going once the science was proven.