No, it is not "that's still unfolding". It is a published WHO report. The consequences may be unclear yes, so we do not spceculate indeed. -  
Well, then add EPA's conclusions. But that is no reson to omit WHO results. Now this: you say "very recently" "recenticism" "still unfolding" (quod non), "we don't yet know if it has enough weight" (WP:OR you ask?),  "other sources like the EPA ... conflict" (OR again, and why shold EPA not be in there?), "Others are beginning to respond directly" (are you a journalist?), "some time to flesh itself out" (wiki wait for what?). In general, you are only asking for time. Are you sure you have no WP:COI? -