He said just putting the ash into pits at La Collette was not a good use of land.

BBC: La Collette incinerator

"There's very little we can do to mitigate it because the procedures we use to clear passengers and cargo, they're responsible I think for the fact that we have a very safe aviation system and we have a very good land migration system where we know who's coming into the country, " she said.

CNN: Longer lines at airports due to budget cuts?

Much of it goes into joint ventures with local partners, so Chinese land, labour and capital equipment are put to good use.

ECONOMIST: China��s private surprise