Ah. Another airing of the "most of the Western world is dehydrated" claim. I've never seen any convincing evidence for this, and it is listed as false at the Urban Legend Reference Pages
http://www.snopes.com/toxins/water.htm (although I admit their arguments are not entirely watertight - pun intended).
Also, I used to be marginally connected to Stanford U in a previous job, and this group were usually looking for subjects holding PPL/IR & instument current - there were lots of these in the SF Bay Area. I haven't read the study, but my guess is that "Airline pilots" may be journalistic exaggeration.