研究称PM2.5增加老年女性患痴呆症风险

Older women living in places with high concentrations of fine particulate matter — the kind common in air pollution across China — may be at much greater risk of dementia, including dementia related to Alzheimer’s disease, according to a study overseen by scientists in Southern California that was published this week.

本周发表的一项由南加州的科学家负责的研究表明，居住在细颗粒物浓度较高地区——中国各地大气污染中常见的那种——的老年女性患痴呆症的风险可能要大得多，包括和阿尔茨海默氏症有关的痴呆症。

The study, led by researchers at the University of Southern California, found that older women who lived in areas where the fine particulate matter exceeded limits set by the United States Environmental Protection Agency had an 81 percent greater chance of general cognitive decline and were 92 percent more likely to develop dementia, according to a report of the research on the university’s website.

该研究由南加州大学(University of Southern California)的研究人员主持。刊登在该大学网站上的一份研究报告称，这项研究发现，所居住地区的细颗粒物超过美国环境保护局(Environmental Protection Agency)设定上限的老年女性一般认知功能下降和患痴呆症的可能性分别高出81%和92%。

The study says air pollution could be responsible for up to 21 percent of dementia cases, if the findings translate to the general population, the report said.

该报告称，研究认为如果研究结果适用于普通人群，大气污染可能要为高达21%的痴呆症病例负责。

The paper was published Tuesday in Translational Psychiatry, a Nature journal.

研究论文周二发表在《自然》(Nature)旗下的期刊《转化精神病学》(Translational Psychiatry)上。

The fine particulate matter is PM 2.5, which is 2.5 micrometers or smaller in diameter. It embeds deep in the lungs and penetrates into the bloodstream. It is the most damaging element of toxic air in China, which has some of the world’s most polluted cities. Most of China’s PM 2.5 comes from coal-fired plants, but a significant portion is generated by vehicles.

这种细颗粒物是PM 2.5，即直径不大于2.5微米的颗粒物。它能够深入肺部，并进入血液。它是中国有毒空气中危害最大的成分，这里有全球污染最为严重的城市。中国的PM 2.5大部分来自燃煤电厂，但车辆产生的PM 2.5也占很大比例。

The study is especially relevant to China in other ways. China has one of the world’s biggest and fastest-growing populations of older adults. Ten percent of its 1.4 billion people are 65 years old or older, according to statistics from the World Bank.

这项研究和中国的相关性特别大还体现在其他方面。中国的老龄人口规模和增长速度在全球名列前茅。根据世界银行(World Bank)的统计数据，中国14亿人口中，65岁及以上者占10%。

The report on the University of Southern California website said PM 2.5 enters the body through the nose and can then embed in the brain.

南加州大学网站上的这份报告称，PM 2.5会通过鼻子进入人体，并且可能会进入大脑。

“Cells in the brain treat these particles as invaders and react with inflammatory responses, which over the course of time, appear to exacerbate and promote Alzheimer’s disease,” said Prof. Caleb Finch, one of the authors of the study, according to the report. Professor Finch works at the U.S.C. Leonard Davis School of Gerontology.

报告称，该研究论文的作者之一凯莱布·芬奇(Caleb Finch)博士表示，“大脑中的细胞会把这些颗粒物当作入侵者，做出炎症反应。随着时间的推移，炎症反应似乎会恶化，并促使阿尔茨海默氏症的发展。”芬奇博士任职于南加州大学莱昂纳德·戴维斯老年医学学院(U.S.C. Leonard Davis School of Gerontology)。

“Although the link between air pollution and Alzheimer’s disease is a new scientific frontier, we now have evidence that air pollution, like tobacco, is dangerous to the aging brain,” he added.

“尽管空气污染和阿尔茨海默氏症之间的联系是一个新的科学前沿领域，但我们现在有证据证明，空气污染就像烟草一样，对不断老化的大脑有害，”他补充说。

Women with the genetic variant APOE4, which increases the risk of Alzheimer’s disease, were more likely to be affected by high levels of air pollution.

基因变异APOE4会增加患阿尔茨海默氏症的风险，携带该基因变异的女性受严重空气污染影响的可能性更高。

A growing number of studies look at the long-term health effects of air pollution. Research done in the 1990s in Los Angeles and published in The New England Journal of Medicine showed that children can suffer permanent lung damage from prolonged exposure to high levels of air pollution.

关注空气污染对健康长期影响的研究越来越多。90年代在洛杉矶进行并发表在了《新英格兰医学杂志》(New England Journal of Medicine)上的研究表明，长期暴露在严重空气污染环境下的儿童可能会受到永久性的肺部损伤。

Columbia University researchers found that prenatal exposure to air pollution could result in children with greater anxiety, depression and attention-span disorders.

哥伦比亚大学(Columbia University)的研究人员发现，产前暴露在空气污染环境下的产妇生下的孩子可能会出现更严重的焦虑、抑郁和注意力障碍。

In February 2016, a group of scientists from the United States, Canada, China and India said they had found that air pollution caused more than 5.5 million premature deaths in 2013. Of those, 1.6 million were in China and 1.4 million in India.

2016年2月，来自美国、加拿大、中国和印度的一批科学家称他们发现2013年，空气污染导致逾550万人过早死亡。当然，中国和印度分别占160万和140万。

Among Chinese, awareness of toxic air has soared. Years ago, some prominent Chinese internet personalities began publishing on their microblogs the PM 2.5 concentrations in Beijing that were being reported in real-time by a United States Embassy Twitter account. The attention generated by those posts and a particularly severe bout of toxic air in January 2013 compelled senior Communist Party officials to allow state news organizations to publish many more stories on air pollution.

中国民众对有毒空气的意识急剧增强。数年前，中国的一些网络名人就开始在自己的微博上公布北京的PM 2.5浓度。相关数据由美国大使馆(United States Embassy)的Twitter账号实时通报。那些帖子引发的关注和2013年1月爆发的一次特别严重的空气污染，迫使共产党高级官员允许官方新闻机构发表更多有关空气污染的报道。