What did you boss say when you told him last week? Has he still not approached this person re: his personal health habits yet? FFS! You can seriously shoot an email off to HR with CONFIDENTIAL as your subject line, sadly this is something HR people have to handle on a fairly regular basis. :-(
Re: Because I know you all want to hear about my co-worker
I'd start leaving air fresheners all around your desk...you'll get a nice scent and MAYBE he will get the message.
You should plant air fresheners in his office. Anonymously. Maybe he'll get the point.