Maybe this was the day on air pollution, in HK Exibition Centre? I went too; a good event, with much enthusiasm, but sadly not big impact outside the room.
Yes, index deserves to be better known. I suggested to Tony Hedley and colleague of his that might try some way to indicate more re people – individuals – dying and falling sick from air pollution. Right now, rather "dry" with numbers, I think: learn of lots of people sick/dying, but just numbers.