Hacking Cough

I have had this really bad cough for about 6 years, and I have never been able to figure out where it came from. I was of course relating it to the fact that I smoke, but that was incorrect.

http://news.yahoo.com/s/ap/20090914/ap_on_sc/us_sci_germs_in_the_shower
After hearing/reading this story, I replaced my plastic Showerhead with a solid metal one, and my cough has almost dissapeared after several weeks.

At Home Depot they have an Aquadyne fixed showerhead that is solid brass with chrome finish (no plastic). The bacteria in the story above don't like metalic showerheads.