I strongly suggest that, unless you are gluttons for punishment, you ignore Bluemerle's post [not personal to you Bluemerle]. We went through all that "ICI are murderers" conspiracy theory last year on this board [or was it earlier this year?].
Purdey has very little support - although it does include Prince Charles. He claims BSE is non-infectious, but the main way of confirmation of the disease for its first few years was by infection of mice. He claims CWD in wild deer in N America is by OP poisoning - WILD deer - who puts OP on them then? Hyper-Al, two posts ago, also correctly criticized the manganese in soil theory.
Then there is the "gulf war syndrome" thesis - yes - it was harmful, it just might have been caused by OPs [though the evidence is that it was vaccination interactions] - but as far as I know not one single case was diagnosed as vCJD.
Mark you I do agree with some of what he says about OP being potentially harmful.
While the vast bulk of QUALIFIED scientists believe the infection story then Purdey's way out unsubstantiated views will have no investment significance - even if he is right! - which I do not believe for one second.