Innumerably many valid statements of the form 'if P then Q' can be generated.

But dissemination of one by a govt. scientist in a prominent medical journal, however, indicates that they think it likely enough to be true.

Or it means that they think that were it to be true, it would calamitous, and thus we'd better think and work really hard to establish whether that is the case. And in 1983, it was not known if it was the case.