According to an article found here:
http://www.vny.com/cf/News/upidetail.cfm?QID=190259
A substance known as SEFA - sucrose esters of fatty acid, can absorb such substances as DDT, PCB and dioxin, with the resulting chemical biodegradable like edible oils. SEFAs are found in Olestra. This may or may not be practicle, but it is interesting.