On 17/08/2014 22:13, Tim Streater wrote:
In article , harryagain
wrote:
....
Who wants slightly radioactive building blocks laced with arsenic and
other heavy metals?

All breeze blocks are slightly radioactive. Granite and coal are too,
more so.

There is also quite good, if circumstantial, evidence that slightly
raised background radiation levels are good for human health.

--
Colin Bignell