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進入英語學習論壇下載音頻 去聽寫專區一展身手

Ever wondered how far your sneeze goes? Or if you can stop germs from spreading by cupping your mouth with your hand when you cough? With a giant mirror and high-speed camera, scientists in Singapore are trying to find out how airborne transmission of flu viruses takes place, or if it happens at all.

The equipment allows them to observe real-time a person's spray of minute liquid droplets when coughing, sneezing, laughing and talking, and they hope the results can be used to make better guidelines for infection control.

Julian Tang, a virologist and consultant with Singapore's National University Hospital said: "It's really to inform infection control teams, because there is controversy now about which pathogens, e.g. flu, are airborne and if so, how significant this route is compared to others, such as direct contact," said team leader.

While it is likely a flu sufferer can infect others by coughing or sneezing, little is known about the distances a cough or sneeze travels and the volume of air - and viruses - packed into it. Are flu viruses transmitted while airborne? Which is more dangerous: Coughing or sneezing or even laughing? Infection control guidelines are mostly based on modeling studies and expert estimates, not hard scientific data. In their $833,000 study, funded by the National Medical Research Council of Singapore, Tang and colleagues designed a large concave mirror, akin to those used in astronomical telescopes.

Along with a camera that can capture up to 250,000 frames per second, the scientists can observe the aerosol, or spray, produced by a cough or sneeze across the mirror.

Using volunteers, Tang and his colleagues will study the velocity and distance of exhaled airflows, or plumes, produced by coughs and sneezes, and even laughing, crying, singing, whistling, talking, snoring and breathing.

"We will be studying these other forms of plumes, where possible, as all forms of exhaled jets have the potential to carry infectious agents over greater distances," Tang said. They will evaluate interventions such as coughing into a loosely clenched fist, a tissue and different types of face masks to see how effective they are in containing airflows.

"What people do every day, we can visualize in real-time. Studying intervention is very important because we want to know how effective they are," Tang said.

"This may have budgetary implications when planning for the next pandemic."

去聽寫專區一展身手

（中國日報網英語點津 Helen 編輯）

About the broadcaster:

Lee Hannon is Chief Editor at China Daily with 15-years experience in print and broadcast journalism. Born in England, Lee has traveled extensively around the world as a journalist including four years as a senior editor in Los Angeles. He now lives in Beijing and is happy to move to China and join the China Daily team.