Re: Smell Test
I agree -- this does not look like a credible result. Instead it looks like 'researchers' making outlandish claims to get attention.
As the saying goes: extraordinary claims requires extraordinary proof. Surprising results are a reason to do a carefully planned, directed study. Not a reason to send off press releases.
As for economic impact and risk, that is *really* difficult to estimate and easily manipulated. Is going for a walk better than watching TV while eating chocolate covered bacon? You are vastly less likely to be hit by a car while watching TV, and being hit by a car can cost millions in medical bills and lost productivity.