Environmental scientists dream of eliminating pollution with natural resources, but that's tricky when it comes to heavy metals. Plants won't work for cleaning polluted water, and only some of them grow large enough to absorb those toxic materials. Researchers may have a relatively simple answer to the problem, though: genetically engineered baker's yeast. Their modified organism uses a cell membrane 'anchor,' and peptides that bind with metals like cadmium, copper and nickel to absorb their ions. The result? The best yeast strains can mop up 80 percent of metal ions without nasty effects -- you'd just have to scoop up the yeast after a cleanup operation.