Daily News Archive
From August 22, 2001

New Portable Devices can Detect Pesticides

Researchers at the University of Wisconsin have created a simple way to detect dangerous levels of toxins in the air including pesticides, according to the August 17 issue of the Journal Science. A small device that can be worn as a badge will change color when exposed to organophosphate chemicals and chemicals produced by decaying food. These devices can measure both immediate and cumulative exposures. Early uses will be available within two to three years.

This is how it works: liquid crystals are bonded to a gold corrugated surface. When exposed to certain chemicals that "match" the crystals, they change orientation and also the way they refract light, thus changing color. Although technology for similar uses does already exist, this is the first that is easily portable without having to use electricity.

"The badge could be worn by children or even agricultural workers to measure personal exposure to pesticides," said Nicholas Abbott, a member of the research team. Many are interested in the benefits these devices present. Parents could keep track of the chemicals their children are exposed to. Farmers could detect whether their fields are safe to work in. Food freshness in grocery stores can be measured. Other groups interested in this technology are the U.S. Army and American chemical companies.

Environmentalists are wary of the chemical companies' interest. They fear the companies may buy out the inventor, thereby curbing public knowledge of pesticide use.
To read articles on these devices from Reuters, WebMD Medical News, and New Scientist, go to http://www.mindfully.org/Health/Chemical-Sensor-New.htm.