如何降低空气质量差带来的风险
📖 逐句对照翻译
Air quality differs from place to place and day to day.
空气质量因地点和日期而异。
But about 99 percent of the world’s population breathes air at some point that does not meet pollution guidelines set by the World Health Organization (WHO).
但全球约99%的人口在某个时刻呼吸的空气不符合世界卫生组织（WHO）设定的污染标准。
Different forms of air pollution kill about 7 million people each year, the U.N. health agency estimates.
联合国卫生机构估计，不同形式的空气污染每年导致约700万人死亡。
But health experts say there are some actions individuals can take to protect themselves, even in the world’s most polluted cities.
但健康专家表示，即使在世界污染最严重的城市，个人也可以采取一些行动来保护自己。
The first step is to start with the understanding that air is not only polluted when it looks smoky or smoggy, said Tanushree Ganguly.
塔努什里·甘古利表示，第一步是要认识到，空气并非只有在看起来烟雾弥漫或雾霾严重时才算受到污染。
She is an air quality expert with the Energy Policy Institute of Chicago’s India program.
她是芝加哥大学能源政策研究所印度项目的空气质量专家。
“Blue skies can’t guarantee you clean air,” Ganguly told The Associated Press.
甘古利告诉美联社：“蓝天并不能保证空气清洁。”
Pollutants and their sources
污染物及其来源
Air pollutants often come from people burning things.
空气污染物通常来自人们燃烧物品。
Examples include fuels as well as clearing operations involving crops or trees.
例子包括燃料以及涉及农作物或树木的清理作业。
Pollutants can also be released from wildfires.
污染物也可能从野火中释放。
Among the most dangerous particles we can breathe in are called particulate matter.
在我们能吸入的最危险的颗粒中，有一种被称为颗粒物。
The smallest of these are known as PM 2.5.
其中最小的被称为PM2.5。
This is because they are less than 2.5 microns in diameter.
这是因为它们的直径小于2.5微米。
These particles can travel deep inside human lungs and are mostly created by burning fuels.
这些颗粒能够深入人体肺部，主要由燃烧燃料产生。
Larger particles, known as PM 10, are linked to agriculture, roadways, mining or wind-blown dust.
较大的颗粒物，称为PM10，与农业、道路、采矿或风扬尘有关。
Other dangerous pollutants include gases like nitrogen dioxide or sulfur dioxide, which are also produced from burning fuels.
其他危险污染物包括二氧化氮或二氧化硫等气体，这些气体也是燃烧燃料时产生的。
This information comes from Anumita Roychowdhury, an air pollution expert at the Center for Science and Environment in New Delhi.
这一信息来自新德里科学与环境中心的空气污染专家阿努米塔·罗伊乔杜里。
Health effects
健康影响
The American-based Health Effects Institute says air pollution is the second-largest risk factor for early death worldwide, behind high blood pressure.
总部位于美国的健康影响研究所表示，空气污染是全球早逝的第二大风险因素，仅次于高血压。
Short-term exposure can cause asthma attacks and increase the risk of heart attacks and stroke, especially in older people and those with existing medical problems.
短期接触可能引发哮喘发作，并增加心脏病发作和中风的风险，尤其是对老年人和已有健康问题的人群而言。
Long-term exposure can cause serious heart and lung problems that can lead to death.
长期接触会导致严重的心脏和肺部问题，甚至可能致命。
A recent study by the U.N. children’s agency UNICEF found that more than 500 million children in East Asia and Pacific countries breathe unhealthy air.
联合国儿童基金会最近的一项研究发现，东亚和太平洋国家的5亿多儿童呼吸着不健康的空气。
The pollution is linked to the deaths of 100 children under age 5 every day.
污染每天导致100名5岁以下儿童死亡。
June Kunugi, UNICEF’s Regional Director for East Asia, said the polluted air limits growth, harms lungs and affects thinking abilities.
联合国儿童基金会东亚区域主任琼·库努吉表示，受污染的空气限制了生长，损害肺部，并影响思维能力。
“Every breath matters, but for too many children every breath can bring harm,” she said.
她说：“每一次呼吸都很重要，但对太多孩子来说，每一次呼吸都可能带来伤害。”
How to tell if air is safe?
如何判断空气是否安全？
Over 6,000 cities in 117 countries now record and follow air quality levels.
目前，117个国家的6000多个城市正在记录并跟踪空气质量水平。
Many mobile apps include air quality information as well.
许多移动应用也包含空气质量信息。
But it can be difficult to know how bad the air is by looking at these numbers.
但是，仅凭这些数字很难了解空气污染有多严重。
To help people better understand air quality levels, many countries have established an air quality index, or AQI.
为了帮助人们更好地了解空气质量水平，许多国家建立了空气质量指数，即AQI。
Larger numbers on this index mean worse air.
该指数数值越大，表示空气质量越差。
Different countries have different air quality standards.
不同国家有不同的空气质量标准。
For example, India’s daily PM 2.5 limit is more than 1.5 times higher than in Thailand and 4 times higher than WHO standards.
例如，印度的每日PM2.5上限是泰国的1.5倍多，是世界卫生组织标准的4倍。
How can you protect yourself?
你如何保护自己？
For individuals, experts say the goal should be to limit exposure when air quality is bad, by staying indoors or wearing a mask.
专家表示，对个人而言，目标应该是在空气质量差时减少暴露，尽量待在室内或佩戴口罩。
This is not always possible, though.
但这并不总是可行的。
Danny Djarum is with the World Resources Institute.
丹尼·贾鲁姆在世界资源研究所工作。
He told the AP there are many people who live or work outside and “can’t really afford” to stay indoors.
他告诉美联社，有许多人在户外生活或工作，他们“实在负担不起”待在室内的费用。
People also need to watch indoor air pollution that can be caused by common household activities like cooking or burning incense.
人们还需要注意由烹饪或烧香等常见家庭活动引起的室内空气污染。
What are the benefits — and limitations — of air purifiers?
空气净化器有哪些好处和局限性？
While air purifiers can help reduce indoor air pollution, experts say they do have limitations.
虽然空气净化器有助于减少室内空气污染，但专家表示它们确实存在局限性。
The devices work by pulling air from a room and then pushing it through a filter that traps pollutants.
这些设备的工作原理是抽取室内的空气，然后将其推送通过一个能捕获污染物的过滤器。
The filtered air is then sent back into the room.
过滤后的空气随后被送回室内。
Air purifiers work best when used in small spaces and when people are nearby.
空气净化器在小空间内且有人在场时使用效果最佳。
This is because they can only clean a certain amount of air, said Rajasekhar Balasubramanian of the National University of Singapore.
新加坡国立大学的拉贾塞卡·巴拉克里希南表示，这是因为它们只能净化一定量的空气。
He added, “If we have a tiny air purifier in a large room, it won’t be effective.”
他补充道：“如果在一个大房间里放一台小型空气净化器，那将不会有效。”
I’m John Russell.
我是约翰·拉塞尔。
And I'm Caty Weaver.
我是凯蒂·韦弗。
Aniruddha Ghosal reported on this story for the Associated Press.
阿尼鲁达·戈萨尔为美联社报道了此事。
John Russell adapted it for VOA Learning English.
约翰·拉塞尔为VOA英语学习频道改编了它。
