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toxins

New cloth self-cleans by killing bacteria

Tossing clothes into the wash when dirty is so last year, thanks to a discovery by chemists out of the University of California at Davis. Near-ordinary cotton may simply need be exposed to light to get busy killing bacteria and breaking down toxic chemicals such as pesticide residues.

Ning Liu, a doctoral student at UC Davis, worked with textile chemists Gang Sun and Jing Zhu to develop a method that incorporates a compound (2-AQC) into cotton fabrics. When exposed to light, it produces reactive oxygen species such as hydrogen peroxide that kill bacteria and break down toxins.

While Liu says 2-AQC is more expensive than other compounds, it is difficult to remove from cotton due to strong bonding, and cheaper equivalents should work, too.

"The new fabric has potential applications in biological and chemical protective clothing for health care, food processing, and farm workers, as well as military personnel," she says.

The team reported on its findings in the Journal of Materials Chemistry last month, shortly before another study out of the University of Iowa chronicled the vast presence of even drug-resistant disease-causing bacteria on hospital curtains.… Read more

Material alert: Toxic flame retardants in baby products

About 80 percent of commonly used baby products recently surveyed by researchers at the University of California at Berkeley, contain toxic or untested halogenated flame retardants, and 36 percent contain chlorinated Tris--a toxin that, along with the related brominated Tris, was banned for several years in the 1970s.

What's more, the flame retardants--there to meet California standard TB117 that consumer items withstand a small open flame--are easily rendered ineffective when put in, for instance, baby furniture with fabric covers that are not required to be resistant, says chemist and visiting scholar Arlene Blum, who helped organize the study just reported in in the journal Environmental Science and Technology.

"The California furniture flammability standard called TB117 does not provide proven protection from fire," she says. "If we can change that requirement, we can have a positive effect worldwide, because these flame retardants are not just a California or U.S. problem--they've become global pollutants."

The semi-volatile chemicals get into the air and then into dust, where researchers say they can be ingested or form films on walls and windows. (An April 2011 UC Berkeley study found that Latino children in the U.S. have seven times the level of flame retardants in their blood than those living in Mexico.)… Read more

Silicon 'nose' turns cell phones into toxin detectors

The developers of a tiny silicon chip that can be embedded in cell phones say it could detect and then map the location and extent of gas leaks and toxins in the air.

"Cell phones are everywhere people are," says Michael Sailor, professor of chemistry and biochemistry at the University of California at San Diego, who heads the research effort. "This technology could map a chemical accident as it unfolds."

Sailor's team at UCSD is working with a San Diego start-up called Rhevision to develop the tiny sensor. They're currently building a prototype that … Read more

Recyclables take a world tour

Ever since I came to the United States from my native Europe, I have been curious about the country's recycling practices. What happens to the mess of old newspapers, plastic boxes, food cans, and wine bottles that piles up each week? (Back home, we have to arrange it all neatly in separate containers.)

I got the answer when I visited the Davis Street Transfer Center, a waste management center in San Leandro, Calif. Here is a photo gallery showing how that facility sorts through those messy heaps.

I was surprised to find out that, after being sorted at the … Read more