Dr. Elizabeth Pilon-Smits, professor and lab director of the Pilon-Smits Lab at Colorado State University, has studied the use of plants to facilitate environmental cleanup for many years.  Pilon-Smits and many other researchers in the lab are dedicated to unraveling the mystery of how certain plants are able to take up toxins from the environment and store them in their tissues.  A better understanding of this natural phenomenon will further advance the use of plants as a form of environmental cleanup across the planet.

 

Environmental cleanup is a multi-billion dollar industry, involving energy intensive, large-scale efforts and costly machinery.  These extensive methods are currently the most accepted approaches to environmental cleanup; however, they are not the only available options. The use of plants as a solution to the world’s environmental pollutant problem is becoming a more popular approach every year. 

 

Plants have impacted the world for hundreds of millions of years.  They are responsible for everything from the world’s supply of crisp air and savory foods, to the fragrant roses that lovers give their sweethearts.   In addition to looking swell and smelling sweet, plants are now turned to for their ability to efficiently clean up toxins from the environment. 

 

The use of plants to facilitate environmental cleanup is referred to as “phytoremediation.”  The term phytoremediation is true to its roots; derived from the Latin words phyto, meaning “plant,” and remidium, meaning “restoring balance.”  Phytoremediation is often employed to return an area affected by harmful human pollutants back to its original balanced state.

 

Human pollutants can enter the environment from many different sources.  Chemical spills, military activities, agriculture, industry, and other human-environmental interactions can introduce toxins into the environment that may be dangerous or even deadly to some local plants and animals. However, certain plants, such as mustard plants, have adapted to be able to grow and thrive in polluted environments.  These plants are able rid the environment of pollutants using a variety of plant processes. 

 

Some plants breakdown pollutants into a less harmful state without ever introducing the toxin into their tissues. The toxins are broken down in the area that surrounds the root of the plant known as the “root zone” through a process called "stabilization." Some Plants take up toxins and incorporate them into their tissues. Once inside the plant, the toxins will undergo one of three plant processes;  degradation, volatilization, or extraction. 

 

Degradation — Plants break down

pollutants into harmless substances.

Once broken down, the previously toxic

compounds are safely stored in the plant

or released back into the soil.

Degradation is most often used to

remediate an area affected by organic

pollutants such as herbicides and

pesticides.

 

Volatilization — Plants take up

pollutants from the air or from the soil,

breaks them down into less harmful

compounds, and release the now

harmless compounds into the air through

openings in their leaves. This process is

often used to remove pollutants entirely

from the soil and letting it diffuse in the

atmosphere.  

 

Extraction — Plants uptake pollutants

from the soil and store them in high

concentrations in plant tissues.                            Urban Omnibus. 2010; From Brownfields to Greenfields: A Field Guide to Phytoremediation.

The plants are then harvested to remove

the toxins completely from the environment. 

This method is often used to remove harmful

metals from the soil. 

 

The use of phytoremediation in the worldwide

remediation market has increased over three

times in the last five years and continues to

grow in popularity.  Its relatively low costs and

low energy requirements compared to

alternative environmental cleanup methods

make it an attractive option for large scale

soil and water cleanups. Because

phytoremediation is primarily driven

by solar energy, polluted areas can be

cleaned up using plants for one-tenth the cost

of alternative methods.

 

The Pilon-Smits Lab continues to research

phytoremediation hoping to discover more

efficient methods of using plants to clean

up polluted environments. This increased

efficiency will lead to a cleaner environment

and overall healthier future.