研究称空气污染可能加速大脑衰老

 　　Exposure to air pollution may hasten brain aging, a new study has found.

　　一项新研究发现，暴露在空气污染中可能会加速大脑衰老。

　　Researchers studied 1,403 women without dementia who were initially¹ enrolled² in a large health study from 1996 to 1998. They measured their brain volume with magnetic resonance³ imaging scans in 2005 and 2006, when the women were 71 to 89.

　　这项研究的对象为1403名未患痴呆症的女性，她们曾在1996年至1998年间参与过另一项大型健康研究。在2005年和2006年，研究人员用磁共振成像扫描的方式，测量了这些年纪在71岁至89岁之间的女性的脑容量。

　　Using residential⁴ histories and air pollution data, they estimated their exposure to air pollution from 1999 to 2006. They used data recorded at monitoring sites on exposure to PM 2.5 — tiny particulate⁵ matter that easily penetrates⁶ the lungs.

　　研究人员利用居住记录和空气污染数据，对她们从1999年到2006年暴露在空气污染中的情况进行了估算。他们使用了监测PM 2.5的站点记录的数据。PM 2.5是一种容易进入肺中的微粒物。

　　研究称空气污染可能加速大脑衰老

　　Each increase of 3.49 micrograms per cubic centimeter cumulative⁷ exposure to pollutants⁸ was associated with a 6.23 cubic centimeter decrease in white matter, the equivalent of one to two years of brain aging. The association remained after adjusting for many variables.

　　每立方厘米中累积污染物每增加3.49微克，脑白质就会减少6.23立方厘米，相当于大脑衰老一到两年。根据多个变量进行了调整后，这种相关性依然存在。

　　Previous studies have shown that air pollution can cause inflammation and damage to the vascular⁹ system, but this study, in The Annals of Neurology, showed damage to the brain itself.

　　之前的研究表明，空气污染可能会导致血管系统发炎受损，而发表在《神经学年报》(The Annals of Neurology)上的这项研究表明，空气污染会导致大脑受损。

　　“This tells us that the damage air pollution can impart goes beyond the circulatory system,” said the lead author, Dr. Jiu-Chiuan Chen, an associate professor of preventive medicine at the Keck School of Medicine at the University of Southern California. “Particles in the ambient air are an environmental neurotoxin to the aging brain.”

　　“这告诉我们，空气污染带来的危害不仅限于循环系统，”文章的第一作者、南加州大学凯克医学院(Keck School of Medicine at the University of Southern California)预防医学副教授陈居泉(Jiu-Chiuan Chen)博士说。“对日渐衰老的大脑来说，周围空气中的颗粒物是自然环境中的神经毒素。

1 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

2 enrolled   

adj.入学登记了的v.[亦作enrol]( enroll的过去式和过去分词 )；登记，招收，使入伍（或入会、入学等），参加，成为成员；记入名册；卷起，包起

参考例句：

• They have been studying hard from the moment they enrolled. 从入学时起，他们就一直努力学习。 来自《简明英汉词典》
• He enrolled with an employment agency for a teaching position. 他在职业介绍所登了记以谋求一个教师的职位。 来自《简明英汉词典》

3 resonance   

n.洪亮；共鸣；共振

参考例句：

• Playing the piano sets up resonance in those glass ornaments.一弹钢琴那些玻璃饰物就会产生共振。
• The areas under the two resonance envelopes are unequal.两个共振峰下面的面积是不相等的。

4 residential   

adj.提供住宿的；居住的；住宅的

参考例句：

• The mayor inspected the residential section of the city.市长视察了该市的住宅区。
• The residential blocks were integrated with the rest of the college.住宿区与学院其他部分结合在了一起。

5 particulate   

adj.微小的；n.微粒，粒子

参考例句：

• A special group was organized to dig up the particulate of the case.成立了一个专门小组来查明该案件的各个细节。
• Lungs retain relatively insoluble particulate material.肺脏内留有不溶解的颗粒物质。

6 penetrates   

v.穿过( penetrate的第三人称单数 )；刺入；了解；渗透

参考例句：

• This is a telescope that penetrates to the remote parts of the universe. 这是一架能看到宇宙中遥远地方的望远镜。 来自《简明英汉词典》
• The dust is so fine that it easily penetrates all the buildings. 尘土极细，能极轻易地钻入一切建筑物。 来自辞典例句

7 cumulative   

adj.累积的，渐增的

参考例句：

• This drug has a cumulative effect.这种药有渐增的效力。
• The benefits from eating fish are cumulative.吃鱼的好处要长期才能显现。

8 pollutants   

污染物质（尤指工业废物）( pollutant的名词复数 )

参考例句：

• Pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
• The 1987 Amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条（g）的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法

9 vascular   

adj.血管的，脉管的

参考例句：

• The mechanism of this anomalous vascular response is unknown.此种不规则的血管反应的机制尚不清楚。
• The vascular changes interfere with diffusion of nutrients from plasma into adjacent perivascular tissue and cells.这些血管变化干扰了营养物质从血浆中向血管周围邻接的组织和细胞扩散。