Soil retention of pharmaceuticals accurately predicted

BALTIMORE, Maryland, September 20, 2004 (ENS): Researchers and public officials concerned about pharmaceuticals, personal care products and pesticides that have been detected in soil and water now have a new mathematical tool that accurately predicts how long such pollutants will remain in soil.

Johns Hopkins researchers have created a way to determine the extent to which hazardous contaminants will linger on a piece of land and the rate at which they will migrate toward water resources.

The new approach will help regulators decide whether the pollutants need to be removed and how best to accomplish this, the researchers say.

"If we release chemicals into the environment, we need to know what will happen to them," said Thanh Helen Nguyen, a graduate student who played a leading role in adapting the math tool and demonstrating its effectiveness.

"For many years, we've made predictions with a method that doesn't work very well on many chemical pollutants in soil. This new tool does a much better job."

For years, environmental chemists have made predictions about how long the non-ionic pollutants will stay there by using octanol, an organic solvent, as a chemical stand-in for natural organic material. "But this technique doesn't work very well for polar pollutants that interact with surrounding solids in a more complex way," Nguyen said.

The doctoral student gathered 359 data points from published experiments involving 75 chemical pollutants. She then borrowed a medicinal chemist's method of converting each of the 75 pollutants to a mathematical representation.

"We worked with these numbers and came up with a very simple equation that predicts what fraction of these non-charged chemicals will make their home in the soil rather than water under any given set of conditions," Nguyen said. "The equation works very well with complicated chemical structures like pesticides and pharmaceuticals."

Nguyen, who is working toward her doctorate in the Department of Geography and Environmental Engineering, described the improved pollution predictor during an August 26 presentation in Philadelphia at a meeting of the American Chemical Society. "We've had a generally positive reaction to this technique so far," Nguyen told meeting attendees. The researchers' goal is to now move the technology into the mainstream where more environmental regulators and practitioners will have access to it.

Nguyen grew up in Vietnam and completed her undergraduate studies at the Ivan Franko National University of L'viv, Ukraine. Before enrolling at Johns Hopkins, she earned a master's degree in earth and environmental sciences at the University of Illinois at Chicago.

http://www.ens-newswire.com/ens/sep2004/2004-09-20-09.asp#anchor7


Recent news and research

[an error occurred while processing this directive]

Stay Up-to-Date –
Sign up for our Newsletter

NewFarm.org changes daily! Don't miss out on the latest interactive features, columns and news. Sign up now for our monthly e-newsletter and stay connected.

ACTION ALERTS

•Free the meat markets! End packer ownership and stop closed-door deals

• Support Saskatchewan farmers in efforts to block GM wheat

• Stop budget cuts to conservation programs--the one's that help you pay for environmentally sound farming practices!

Share Your Stories

Are you a farmer? A consumer? Whatever story you have to tell, let it be an inspiration to others.
Share it with us now...

T H E    N E W    F A R M – R E G E N E R A T I V E    A G R I C U L T U R E    W O R L D W I D E