Plants like Heavy Metal

If you’re thinking Metallica, you’re on the wrong track. Plants that eat heavy metals like arsenic, lead and mercury might be the solution to cleaning up hazardous wastes.

Heavy metals like arsenic, lead and mercury are dangerous to humans (and to plants). While the human solution to removing heavy metals from soil has usually been bulldozing the site and looking for a better place to dump the dangerous dirt, plants have a very clever solution.

When plants encounter heavy metals that are dangerous to their survival, they don’t have the option to run away. To survive, certain plants have developed a solution: They produce special compounds (phytochelatins) that attach themselves to the heavy metals and detoxify them, making them less harmful to the plant. The plant then carries the heavy metals from its roots to its leaves, where humans can remove them by harvesting the leaves.

After a few seasons of growing the plants, then removing their leaves the heavy metal concentration in the soil would be reduced to a safe level.

So instead of using bulldozing, a costly and environmentally damaging technique, to decontaminate soil, we might soon be able to employ these clever plants to solve the problem!

Image by Ji-Mong Gong The Lab, ABC Science online at http://abc.net.au/science/news/