好英语网健康无价 城市空气污染毁人一生幸福
A recent study has likened city air pollution to smoking a pack of cigarettes each day for 29 years. While the effect on our lungs is undoubtedly troubling, we should also be wary of what the air we breathe is doing to the rest of our bodies.
最近的一项研究将城市空气污染比作29年来每天吸一包烟。虽然空气污染对肺部的影响令人担忧，但我们也应该警惕空气污染对身体其它部位的影响。
The new study monitored ground-level ozone exposure in 7,000 adults living in cities across the US. Generally, urbanites were exposed to between 10 and 25 parts per billion of ozone, where an increase of three parts per billion equates to smoking an extra pack of cigarettes each day. So, even moving from a low-pollution area into one of the cleaner cities could still increase your risk of respiratory diseases like emphysema – which is more commonly associated with smokers.
这项新的研究监测了美国各城市中7000名成年人的地面臭氧暴露情况。一般来说，城市居民接触到的空气中臭氧含量在10亿分之10至25之间，而每增加10亿分之3的量，就相当于每天多吸一包烟。因此，即使从低污染地区搬到更清洁的城市，仍然会增加患肺气肿等呼吸道疾病的风险，而肺气肿通常与吸烟者有关。
The World Health Organization (WHO) now calls urban pollution levels a “public health emergency” because 91% of us live in areas where air pollution exceeds the agency’s guidelines. Right now, 55% of the world’s population lives in urban areas. That figure is expected to rise to 68% by 2050, the United Nations estimates. If urban life is a serious concern for our health, mental wellbeing and outlook, then it is only going to become a greater issue for more of us as time passes.
现在世界卫生组织（WHO）将城市污染程度称为“公共卫生紧急状态”，因为91%的人生活在空气污染超过该机构制定标准的地区。目前，全球55%的人口居住在城市。联合国预计，到2050年，这一比例将升至68%。如果城市生活对我们的身体健康、心理健康和认知状态构成负面的影响，那么随着时间的推移，它将成为许多人的严重问题。
Mental wellbeing
心理健康
Prevalence of psychiatric disorders is significantly higher among people living in urban areas, says a meta-analysis of 20 pieces of research conducted over the past 35 years. Specifically, people in cities suffer from mood disorders and anxiety at a disproportionately high rate.
一项对过去35年进行的20项研究的荟萃分析显示，城市居民中精神障碍的患病率明显偏高。特别是城市里的人患情绪紊乱和焦虑的比例高的离谱。
Compare this to residents who have a sea view – for every 10% increase in the amount of ocean people can see, people’s scores on the Kessler Psychological Distress Scale decreased by one-third of a point. The researchers suggest that “a 20 to 30% increase in blue space visibility could shift someone from moderate distress into a lower category”.
相比之下，住在海边能看到海洋的人数每增加10%，凯斯勒心理压力量表（Kessler Psychological Distress Scale）的得分就会下降三分之一。研究人员表示：“蓝色海景的能见度增加20%至30%，可能会将一个人从中度抑郁转变为较低的抑郁类别。”
Education
教育
Perhaps one of the more surprising ways that cities affect us is by making us less clever. Comparing the results of students taking exams with levels of air pollution on the day of exams shows that performances are worse when pollution is highest. The performance of students completing the same exams in the same cities on different days was compared to the levels of pollution on those days. Even small differences in pollution levels were found to have an effect on educational outcomes.
城市空气污染还有一个更令人惊讶的影响，它会让我们变得不那么聪明。将参加考试的学生成绩与考试当天的空气污染程度进行比较，结果显示，污染程度越高，学生成绩越差。研究人员将同一城市中的学生，在不同时间完成相同考试的表现，与那些日子的污染程度进行比较。发现污染程度的微小差异也会对考试成绩产生影响。
This has a real effect on outcomes later in life. A study in Israel found that high levels of fine particle pollution in the air on the day of high school exit exams had a negative effect on wages in adulthood.
对以后的生活也有实际的影响。以色列的一项研究发现，如果高中毕业考试当天空气中微粒污染程度较高，可能会对成年后的工资产生负面影响。
Weight
体重
Airborne pollution has also been linked to obesity. While the exact mechanism is still debated, and research has largely been conducted in animals, it is thought that pollution alters the body’s metabolism. This is perhaps due to inflammation in the lungs caused by particles of pollution, which triggers a stress response. Hormones released as part of this can also reduce the effectiveness of insulin, raising blood sugar levels. This response is intended to make sure we have a kick of energy at the ready in stressful situations, but, if we are constantly in a state of slight stress caused by air pollution, then it can have long-term effects on how able we are to process sugar – a first step towards diabetes.
空气污染也与肥胖有关。虽然确切的机制存在争议，而且研究主要是在动物身上进行的，但人们认为污染会改变人体的新陈代谢。这可能是由污染颗粒导致肺部炎症引起的，炎症会引发应激反应。应激反应中释放的激素会降低胰岛素的效力，提高血糖水平。应激反应的目的是为我们在紧张的压力状态下准备好能量，如果空气污染不断造成轻微压力，就会对我们如何处理糖产生长期的影响，这也是迈向糖尿病的第一步。
Large studies, such as one conducted in Canada on 62,000 citizens, seem to corroborate this research. In this case, risk of developing diabetes rose by 11% for every 10 micrograms of fine particles per cubic metre of air.
比如，加拿大对6.2万民众进行的一项大规模调查，似乎证实了这一结论。在这种情况下，每立方米空气中每增加10微克微粒，罹患糖尿病的风险就会增加11%。
What can we do to improve our cities?
我们能做些什么来改善城市空气质量？
A small amount of green space can make a big difference – particularly for people in lower socioeconomic categories. But smells can also make cities a more pleasant place to live. Providing an area to retreat away from the bustle of a city can improve people’s psychological wellbeing.
少量的绿地也能产生很大的作用，尤其是对社会经济地位较低的人群。清新的气味也能使城市成为一个适宜居住的地方。提供一个远离城市喧嚣的地方，可以改善人们的心理健康状态。
In Beijing, a “smog free tower” about 7m (23ft) high is claimed to be able to clean the air in an area the size of a football pitch. The structure resembles a giant beehive. Electrical charges suck airborne particles into the tower. The particles are then trapped by a negatively charged dust-removal plate.
在北京，一座高约7米（23英尺）的“雾霾净化塔”据称能够净化一个足球场大小区域的空气。它的结构像一个巨大的蜂巢。电荷把空气中的微粒吸入塔中。然后粒子被带负电荷的除尘板捕获。
In Mexico City, a giant honeycomb-like structure adorns the side of Hospital Manuel Gea Gonzalez. This structure works in a similar way to the catalytic converter in your car. A catalytic coating reacts with dangerous nitrogen dioxide leaving a harmless salt. The designers claim it can remove the equivalent of 1,000 cars-worth of pollution per day.
在墨西哥城，曼努埃尔·盖亚·冈萨雷斯（Manuel Gea Gonzalez）医院的一侧也安装着一个巨大的蜂巢状结构的“空气转化器”。它的工作原理与汽车中的催化转化器类似。催化涂层与有害的二氧化氮发生反应，生成无害的盐。设计师称，它每天可以清除相当于1000辆汽车的污染。