Perhaps a policy of submitting all results that are suitable from all ground investigations to the BGS so that over a few years a massive database is created - some organisations routinely submit borehole logs to BGS already - this is just an extension of that policy. It would be simple enough to un-locate the samples so that they weren't identifiably from 1 site, the source data could be kept confidential any way.
I am slightly concnerned that a background value for BaP has been introduced into reality with so little data behind it, once a number is published no matter what the limitations of the way it was generated that number becomes a FACT and either above or below becomes good or bad, that is human nature.
Clive Williams
Halcrow
a CH2M Hill Company
These are my own personal views
