Whether this reflects macrophagic dysfunction, or the tail-end of a normal population distribution of aluminium clearance and local tissue response, has not been determined.

The costs of international and local transport, warehousing, port clearance and storage should be met by the donor.

"Had this been in place when Vedanta first applied for forest clearance for the Niyamgiri project, it would have stopped the mine in its tracks, due to local opposition, " said Jo Woodman at Survival.