It definitely wasn't pollution, Shanwick passed us an ashtam, it was near where they said it would be. By the time we realised what we were looking at we were in it, and by the time we received climb clearance we were out the other side.
Ref the state of the eruption, my understanding is that the ash has been in the atmosphere for days so the current state of the volcano is not relevant.
The smell was definitely sulphur, and coincided with the discoloured layers we saw.
If I get feedback on the state of the aircraft I will pass it on.
LD