On 30/04/18 16:59, Tim Streater wrote:
In article , Chris Hogg
wrote:

On Sun, 29 Apr 2018 09:40:59 -0700 (PDT), harry
wrote:

The clinker they were made from is slightly radioactive (coal ash) so
actual
clinker block has been replaced with other insulating blocks.

That may be so, but OOI why should coal ash be slightly radioactive,
more so than anything else and enough to warrant it not being used in
cinder blocks?

Coal contains one part per million uranium.

Actually of course everything is "slightly" radioactive, but some
things more so. Like granite, too, so don't go to Dartmoor or you'll
glow.

Actually thet depnds on waqht you mean by 'things' Vast quantities of
pure elements are not radioactive at all.

But any mixture is likely to contain some that are.

Human beings are fairly radioactive, for example.


--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp