Plants Versus Pollution
REMOVING pollutants from contaminated soil and water is a lengthy, expensive, and often difficult business. However, ordinary plants are proving capable of doing the job all by themselves.
Scientists are considering using the common pondweed and periwinkle to clean up old munition sites and reclaim the land. In experiments, sterilized parrot feather and periwinkle extracted TNT so well that within a week no trace of explosive remained in the plants’ tissues, nor did burning them produce an explosion! Other researchers discovered that cells and extracts of the common sugar beet could absorb and degrade nitroglycerin.
What about water heavily contaminated with radioactivity? Sunflowers seem to be helpful. Six-week-old sunflowers were used to tackle contaminated wastewater in an abandoned uranium factory in Ohio, U.S.A. The result? Uranium contamination was reduced from an average of 200 micrograms per liter to below the safety limit of 20 micrograms per liter. Other tests, at the Chernobyl reactor, near Kiev, showed that sunflowers soaked up 95 percent of the radioactive strontium and cesium within ten days!
Farmers may soon be using the yellow iris and the bulrush in their efforts to avoid polluting watercourses with pesticides and herbicides. This decontamination process is accomplished primarily by microbes in the plants’ root systems that break down the contaminants and clean the water.
The above examples illustrate the marvelous capacity of the earth to cleanse itself.