近日，中国东部再次被雾霾笼罩。面对爆表的PM2.5数值，人们纷纷戴上防尘口罩(anti-dust mask)，这些口罩都有哪些常见类型？哪种对抗PM2.5最有效？

 

March is supposed to be a beautiful month. Birds start singing again, trees start showing the first signs of spring, and balmy breezes blow around street corners. But sadly, that’s not all. Flus are common in early spring, pollens are getting ready to cause sneezing and stuffy noses, and PM2.5 is still bothering us.

三月本应是个美丽的季节——莺声燕语，草木新绿，和风送暖。但很可惜，事实并非如此而已。早春时节总是流感高发，还有花粉让人们遭受喷嚏和鼻塞的困扰。此外更有PM2.5依旧令人烦心。

 

This potent combination spells trouble, so take extra precautions with the right mask.

面对这支威力不小的“麻烦军团”，我们要加倍小心，正确选择口罩进行防护。

 

Activated charcoal mask

活性炭口罩

 

If you have to stay in a recently painted room, you should consider wearing an activated charcoal mask to protect yourself against formaldehyde and benzol. Activated charcoal is efficient at absorbing such carbon-based impurities.

如果你不得不待在一处刚刚粉刷过的房间里，那么佩戴一个活性炭口罩以预防甲醛和苯的危害。活性炭能够有效吸收此类含碳物质。

 

Many other chemicals, however, are not attracted to carbon at all. This means that an activated charcoal filter will remove certain impurities from the air while missing others.

然而仍有许多化学物质是碳无法吸附的。也就是说，活性炭在过滤空气中某些杂质时却对其他物质不起作用。

 

Note also that an activated charcoal mask is no longer effective when all of its “bonding sites” are filled. At that point you must replace it with a new one.

同时也要注意，一旦空隙构造中的微孔都被填满，活性炭口罩便会失效。这时候你就要更换一个新的了。

 

Particulate respirator

防颗粒物口罩

 

The intended use of a respirator is to help reduce the wearer’s exposure to airborne particles that could be inhaled and enter the human respiratory system.

防颗粒物口罩的用途是帮助减少空气中可吸入颗粒物进入人体呼吸系统。

 

In the US, to qualify as a certified respirator, the mask must be approved by National Institute for Occupational Safety and Health (NIOSH) as to its respiratory protection efficiency. One of the most common respirator masks is NIOSH N95, which filters at least 95 percent of particles with diameters ranging from 0.1 to 0.3 μm. That means the respirator is effective against dust, pollen and PM2.5.

在美国，防颗粒物口罩必须根据其呼吸防护的有效性，来获得美国国家职业安全卫生研究所(简称NIOSH)的鉴定认证。最常见的一种便是NIOSH N95口罩，它可以过滤掉95%的直径介于0.1至0.3微米之间的微粒。也就是说这种口罩可以有效过滤灰尘、花粉以及PM2.5。

 

Surgical mask

医用口罩

 

Surgical masks are often used to protect the wearer against body fluids from other people. As flu viruses are spread mainly through droplets when infected people cough, sneeze or talk, experts recommend surgical masks to prevent the spread of the illness. “If you’re caring for a family member with influenza, I think a surgical mask is perfectly adequate,” Carol McLay, an infection control consultant, told The New York Times.

医用口罩通常用来有效阻隔人与人之间的体液传播。由于流感病毒主要通过流感患者咳嗽、打喷嚏或说话时的飞沫传播，因此导师建议佩戴医用口罩来阻止病毒的传播。“如果你担心家人感染流感，我想医用口罩就够用了。”传染病防控顾问卡萝•麦克雷在接受《纽约时报》采访时说。

 

But surgical masks are not designed to prevent inhalation of airborne particles, so they aren’t as effective in protecting PM2.5 or pollen.

但医用口罩无法阻隔空气中的可吸入颗粒物，因而无法有效地隔绝PM2.5或花粉。

以上就是新航道托福频道为大家整理的托福阅读材料之雾霾天气应该买什么样的口罩，希望对大家有帮助，更多资讯、资料请访问新航道托福阅读频道 https://www.xhd.cn/toefl/yuedu/