每日英语：A Buying Guide to Air-Pollution Masks

Blue skies were finally visible in the capital on Thursday after the region suffered fromseven straight days of intense pollution, sending consumers out in droves to buy pollution masks.

in droves：陆陆续续，成群结队

Although Thursday’s weather brought a collective sigh of relief from the masses, if past records are any indication, the pollution is bound to return. So one Beijing doctor is asking: what actually makes a good face mask?

Not every mask is equally effective, says Dr. Richard Saint Cyr, a family physician with Beijing United Family Healthcare.

Wearing simple cotton masks or those that don’t fully seal against the face could actually be dangerous because it leads to a false sense of security and even more time outdoors, he says.

seal:密封

“It disturbs me that people are walking around thinking wearing these things is safe, but they almost certainly are not,” says Dr. Saint Cyr.

Of course, there are plenty of people in Beijing who wear no mask at all. PresidentXi Jinping strolled through the popular Nanluoguxiang neighborhoodTuesday, breathing on a day that the air-quality index reached more than 500. The U.S. Environmental Protection Agency says an index of above 300 is “extremely rare” in the U.S. and typically occurs during events such as forest fires.

stroll：漫步，闲逛，巡回演出

But Dr. Saint Cyr suspects that the lack of scientific data on the most effective types of masks has made many people wary of buying any at all. The doctor, who also keeps a blog called My Health Beijing, has started a project to test masks currently on the market, using a crowdfunding approach to pay for testing as many as 200 masks, which will be evaluated by a California company.

wary of：小心翼翼，谨慎的

For those looking for protection right away, Dr. Saint Cyr offers these tips for mask shopping:

• The most important element is how a mask fits against the face. Air gaps that allow particulate matter in render the mask basically useless, he says. Some of the popular Chinese-brand masks sold in 7-Eleven stores around Beijing are no good, he says. One, Ludun, touts its 99% efficiency, he says. But within the mask, the filter is just a tiny square inside a cotton mask. The vast majority of the mask is cotton, with lots of leakage. “It just doesn’t fit well.” What’s most worrisome, he says, is “people are walking around thinking they’re protected.” One good test is whether eyeglass-wearers find their glasses steamed up. If so, the masks aren’t air-tight.
• The mask’s material – its ability to filter out the smallest particulate matter – also is important. Cotton masks or surgical masks aren’t effective, Dr. Saint Cyr says. The U.S. National Institute for Occupational Safety and Health offers mask certification based on the amount of particulate matter filtered out. An N95 rating, for example, means a mask filters out 95% of airborne particulates.
• Good ventilation matters, especially for those who might want to exercise outside in the mask. Some masks rest away from the face, creating a comfortable breathing space, while others feel too suffocating for heavy exertion.
• Style, too, is a consideration. Some masks, like Respro, make the wearers look like Darth Vadar, while others, like Totobobo, resemble some sort of alien with white gills. Some blogs suggest placing a second mask over the powerful one, topping off the look with a mask that may be ineffective but aesthetically pleasing. After all, if people feel ugly wearing their masks, they may be less likely to wear them.

particulate matter：微粒物质，悬浮微粒    leakage：泄露      surgical masks：手术口罩

airborne：空气传播的           ventilation：通风设备，空气流通      suffocating：令人窒息的，呼吸困难的

aesthetically：审美地，美学上

The Shanghai Consumer Rights Protection Commission in 2013 tested 17 disposable pollution masks, and rated them (in Chinese) on its website. Dr. Saint Cyr translated the results and published the findings on his blog, calling it “a useful treasure of evidence-based data.” Two of the top five  disposable masks, he reported, were made by 3M.

disposable：一次性的

His new study aims to widen the scope of the Shanghai test, evaluating both pricey reusable masks like Vogmask, Respro and Totobobo as well as cheaper versions by 3M.  Cost, Dr. Saint Cyr says, is one factor that doesn’t seem to matter much. In fact, he says he uses the disposable five-yuan (82-cent) 3M masks himself. “They’re probably better than anything on the market.”

pricey：高价的，过分昂贵的      reusable：可重复使用的

Dr. Saint Cyr estimates his study will be completed by April or May.