voa 科学技术: Daylight Turns Thin Plastic Barrier into ...

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Daylight Turns Thin Plastic Barrier into Germ-Killing Material

FILE - A health worker sprays a colleague with disinfectant during a training session for Congolese health workers to deal with Ebola virus in Kinshasa, Oct. 21, 2014. The process of removing the full-body protective suit is a prime opportunity for infection if the surface of the gear is contaminated.

Daylight-powered germ-killing equipment may someday help protect health workers from deadly microorganisms like Ebola virus disease.

That is a finding from a study published in the journal Science Advances.

Study organizers say they have developed membranes that produce very small amounts of hydrogen peroxide when they are left in sunlight.

Membranes are thin structures that can serve as barriers. They let some things pass through, but other things are blocked. Hydrogen peroxide, a liquid sold in drug stores, works as a disinfectant.

Nearly 500 health workers died in 2014 when Ebola spread through parts of West Africa. Caregivers wear full-body protective suits when they come into contact with patients with infectious diseases. But the process of removing the suits is a time when infection can spread if the surface is covered with microorganisms.

"If there's any live bacteria or virus on the surface, it's still transmissible and could cause infection," said Gang Sun of the University of California, Davis. He is one of the researchers that worked to develop membranes that could cover the outside of protective equipment.

When the chemical molecules on the surface of these membranes are put in sunlight, they react with oxygen in the air to produce small amounts of hydrogen peroxide.

Gang Sun explains that the process creates less hydrogen peroxide than what you would use to remove dirt on clothing, for example. But it is still enough to kill organisms.

Rohan Tikekar is a food scientist with the University of Maryland. He described the development as “quite novel,” or new and different. Tikekar was not involved with the recent study.

He said others have developed materials that produce disinfecting chemicals. But most only work under high-energy ultraviolet (UV) light, and not usual daylight.

The new membrane also works in the dark for at least an hour or two because of chemical properties that can recharge its germ-killing powers. Tikekar called that an important improvement.

Gang Sun said the new membranes could be used for things other than protective gear for health workers. They could also be added to packaging for fruits and vegetables to keep foods fresher and reduce the risk of contamination.

Some versions of the material use natural chemicals. Sun says that one of the next steps is to make it safe to eat.

I'm Jonathan Evans.

Steve Baragona reported this story for VOANews.com. George Grow adapted his report for Learning English. Ashley Thompson was the editor.

We want to hear from you. Write to us in the Comments Section.

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Words in This Story

germ – n. an organism known to cause disease

journal – n. a publication, such as a magazine or newspaper

packaging – n. material used to contain something

transmissible – adj. able to be spread to other people

approach – n. a method; a way of doing things

novel – adj. new or unusual

contamination - n. the process of polluting; the act of harming something

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