Sunday, September 27, 2009

More on Plant VOCs

A follow-up email from Susan McCoy at Garden Media Group offered some follow-up information on the my previous post related to Plants and VOCs (Sept. 6, 2009). My take on it was at least on the right track, unlike some others - but I figure the press release (and upcoming report) is a good opportunity to get some background from the actual scientific experts :

Here's the text from the letter from September 22nd, 2009:

"To Whom It May Concern,
There have been a number of recent discussions resulting from information taken out of context from an American Society of Horticultural Science press release concerning research conducted on plant volatiles in our laboratory at the University of Georgia.

The release indicated that indoor plants have been found to release volatile organic compounds (VOCs). Unfortunately the results were subsequently misrepresented on an internet site, giving the impression that it is undesirable to have plants in our homes and offices.

This could not be further from the truth. All living things give off VOCs; one of the simplest is
CO2 that we emit when breathing. Therefore, solely equating VOCs with “harmful” is totally inaccurate. The fragrance of a rose or the aroma of apple pie are each made up of volatile organic compounds.

The assumption that has incorrectly been made is that all VOCs are equal and are harmful.
Mankind has evolved over hundreds of thousands of years breathing VOCs from plants, nearly all of which are harmless at the concentrations encountered in nature. Unfortunately over the last 150 years there has been a logarithmic increase in the number of synthetic chemicals from other sources to which we are now exposed. A number of these are extremely harmful and in some cases, lethal. These undesirable volatiles represent a serious health problem that is responsible for more than 1.6 million deaths per year and 2.7% of the global burden of disease (WHO, 2002).

Critical questions with regard to VOCs include: What chemicals and what are their
concentrations? In the website account, much was made of a minute amount of volatiles derived from pesticides applied to the plants. In reality, these pesticide-derived volatiles emitted from the Peace lily represented less that four hundredth of one percent (0.038%) of the volatiles given off by the plant. Finding minute amounts of chemicals indicates the extremely high level of sensitivity of the analytical techniques but does not imply a potentially harmful situation.

Our research has shown that while plants give-off a small amount of harmless VOCs, they also
remove significant amounts of toxic VOCs from the air. The net effect is overwhelmingly positive. Plants in homes and offices are not only aesthetically pleasing, they can also increase the quality of the air we breathe and thereby the health of the inhabitants. As we continue to research and learn more about the potential of plants to remove harmful volatile compounds we should generate knowledge that will enhance our ability to create exceptionally healthy indoor environments.

Stanley J. Kays, Professor
University of Georgia

More info and contact for Professor Kays can be found here and I will try to get my hands on the report and see if there are any nuggets of info out there. And thanks Susan for the heads up on this!


  1. At this level of concentration, any VOC's emitted would dissipate before reaching anyone's breathing area...

  2. ...but what about the mold & mildew issues with indoor plants?

  3. The use of a dehumidifier helps with the mold and mildew issues in indoor environments with indoor plants...

    New Jersey Landscape architect NJ Landscape Designer


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