On Sun, 4 Mar 2012 17:33:19 -0000, Bill Grey wrote:

It's a pity we can't ask the folk who lived in Ystalyfera in the Swansea
Valley circa 1866 ...

Or the around Broad Street, Soho, London in 1854. People of
Ystalyfera had obviously not done a proper risk assesment based on
the discoveries of John Snow 12 years previously.

--
Cheers
Dave.