I found this fascinating – saying that wood cutting boards are better than plastic/acrylic cutting boards, and that the best way to kill any residual bacteria on the board is to microwave it for a few minutes each week: www.rodalenews.com/cutting-boards-and-bacteria
The thing is, there is still plenty of advice out there to use plastic or acrylic. Like this: culinaryarts.about.com/od/culinarytools/p/cuttingboards.htm.
Either way, it’s a reminder to take what has become “conventional wisdom” with a grain of salt.