Phytoremediation

[Darkhorse]

Being the chem nerd that I am, I found the newsletter article on phytoremediation quite interesting.  I'm curious-- has any research been done on the effect(s) of these toxins on said plants?  My reasonably educated guess is that the plants are able to break down some of the organic molecules, but probably can't rid themselves of the heavy metals. 

Any thoughts?