Ear ear
Nigel is right I fear. methinks its one of these BSE type issues. "There's no proof etc" and then it turns out there was a problem all along.
We know that many other issues are identified by the sufferers and denied or ignored by the authorities. As my GP once said to me, "You know your body better than anyone else." Julian Soddy made the point well. Felt ill, went back when better, felt ill again. He is far from the only one with a similar story.
An engineer told me (I'm not one so..) that oil seals are "wet" seals. This is born out by the small traces found on every flight that Panorama tested. Others have done the same, with the same result, on many types of a/c.
So, a wet seal fits there doesn't it? Now we're only arguing about the quantity & what is acceptable. no doubt older, less well maintained a/c as well as the known offenders, means you could be on the one that's regularly putting out just a bit more.
Why also do we use Exxon Mobile oil that's full of poisons? There's a French oil that has none? As used on many military a/c including the UKs....wonder why?