Google expand the availability of "sensitive category blocking" (a.k.a "category filtering") worldwide, now launched in Japanese, Chinese, Polish, and Portuguese -- was first launched in August 2009 in beta. "With sensitive category blocking, you can prevent ads from up to 11 specific categories from appearing on your pages. Ads in these categories will be blocked if they're in any of the supported languages, regardless of how they've been targeted to your pages."
To set up, sign in to AdSense, visit Ad Review Center, located under 'AdSense Setup' tab. Clicking 'change,' show you a full list of categories you can block. In addition, to help you understand the impact of applying these filters, Google show you 'percentage of revenue' and 'ad impressions' you've been receiving from each category in the last 30 days.
More Info: Help Center